Ford Model A & B Motors

[old28]

Looking for some information on Ford A & B Motors.

1 -- Will a 1939 Ford top loader trans bolt direct to the A or B block?

2 -- Is an adapter needed for this setup?

3 -- Who sells rod & crank insert bearing mod kits for these motors?

4 -- Who sells HC flat top pistons for a hot rod motor build on A or B?

5 -- Does any one sell a HP kit for these motors?

Thanks in advance, my first Ford A motor build

[Mike V. Florida]

Be sure to also ask these question in sister site to this one "H.A.M.B." if you have not already done so.

[SteveB31]

1. Yes with$500 adapter.
2. Yes
3. Several vendors. Bert's, Brattons, Snyders, Mikes etc
4. same answer as #3
5. Higher compression head, cam, carb. Makes more HP.

Steve Becker
Bert's Model A Center

[Tom Wesenberg]

#4 isn't really possible for the Model A and B, but a head will give you more compression and power.

[old28]

Thanks guys, I will check them out.

[old28]

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If you bore the (A) block .125 over and install a set of 3 ring pistons from Snyder with a milled stock head can you get 7.5 CR?

H & H says 7.5 CR is max for babit bearings to live?

Any one in the Ventura County, CA or LA area know of good machine shop that works on these motors for boring, bearings, Valves?

[MikeK]

Originally Posted by old28

If you bore the (A) block .125 over and install a set of 3 ring pistons from Snyder with a milled stock head can you get 7.5 CR?

No. A stock head is 4.22:1 CR. Taking 0.100" off it (likely too much!) and then facing the .125 over piston tops so you have 0.040" squish clearance with a 7013 R3 compressed gasket will give you ~4.9:1 CR. Milling a stock A head is a losing proposition. Also, 0.125 overbore leaves you with a block that has very narrow siamese areas that will be prone to gasket blowout if you want to make more HP than stock.

You really need to talk to the HAMB guys on one of their banger threads.

[old28]

MikeK -- After reading your information it sounds like a HP flat head is called for. With the same piston setup and a HP Flat head what CR range would I be looking at?

I do not want the cost of an OHV setup. This is my first build of an A or B motor after 40 years of BBC front motor dragster fun. I am learning as I go.

[Mike V. Florida]

Originally Posted by old28

MikeK -- After reading your information it sounds like a HP flat head is called for. With the same piston setup and a HP Flat head what CR range would I be looking at?

I do not want the cost of an OHV setup. This is my first build of an A or B motor after 40 years of BBC front motor dragster fun. I am learning as I go.

There are other heads between the stock and OHC.

The first question you need to ask is how much HP do you want to make?

While there are knowledgable people here, this site leans way towards the stock Model A. The absolute best place for your questions of HP, in my opinion, is the HAMB forum.

[colin1928]

Go to the HAMB look at the at the monthly Banger Meet on the 1st page is a list with lots if tech and build threads read a few that are simular to what you want you engine to be when finished they have from 50 hp to 200 hp builds

[old28]

I am looking at building an A motor a bite like this.
.125 bore
stock stroke (steel crank)
aftermarket intake, headers
2x2 94 carb setup
mallory ign
Larger intake & exh valves
May run insert rod & main bearing (May be to costly)
6.5CR head

Hope to make 75 100 HP. What do you guys think??????
Am I on the right track or out to lunch.
I am thick skin so let me know a better way if there is.

I have a thread on the HAMB also.

[Dodge]

Your off to a good start, maybe you can get one of Tod's new heads, search the threads
here. Also maybe a Stipe 330 or 340 camshaft.
See what others chime in with.

[hardtimes]

Hey old28,
Regarding intake and exhaust valves. You can get benefit/improvement from enlarged INTAKE valves. However, you do not need to change the exhaust valves as they will do the needed work as is. So, save $ and leave exhaust valves as Ford made them.

[old28]

Dodge -- Do you know if a 330 or 340 camshaft will make 75+ HP? New to this forum, who is Tod"s Heads?

hardtimes -- That good news on the exhaust. Do you have a intake size in mind for my
HP range.

[James Rogers]

Originally Posted by old28

Dodge -- Do you know if a 330 or 340 camshaft will make 75+ HP? New to this forum, who is Tod"s Heads?

hardtimes -- That good news on the exhaust. Do you have a intake size in mind for my
HP range.

What are your objectives here? You will be dissapointed in some aspects of a build like this simply because of the design of the engine.

[Kurt in NJ]

here are some dyno tests for a few combinations--
http://www.modelaparts.net/dynosheet...ynosheets.html

[hardtimes]

Originally Posted by old28

Dodge -- Do you know if a 330 or 340 camshaft will make 75+ HP? New to this forum, who is Tod"s Heads?

hardtimes -- That good news on the exhaust. Do you have a intake size in mind for my
HP range.

Well, you had best look into which (A or B) block that you want to start with...this is VERY important , IMO !
In the attached picture of my latest new build, I've used a B block with 1.75" intake valves and stock exhaust valves.
B blocks have distinct advantages, IMO, in some aspects and the A block has what is said to be a THICKER deck ...I'm not sure that this is accurate/true after 85 yrs of rust, wear, etc...

Here is the BEST piece of info/tip that I can give you to start doing what you are saying that you want (i.e.-figure out what block to start with etc).


Get and study a book written by a senior senior ...member here ! This is written information for beginners and for those familiar with the subject.
It will answer many , if not all, of your inquiries.

I used the guidance of this book to build the B that you see here. After getting the 'bugs' ironed out of it, it is a fine piece of equipment/history to listen to. Like Beet Hoven and CCR playing together, eh !!

[old28]

Kurt in NJ ---Thanks for the Dyno Sheet tests. A lot of information and combinations. As I start moving forward on this project I feel like a motor in the 75-90 HP range will work well for my project. I am looking at running a 28 roadster with an A motor, 39 trans & a Banjo rear end in the TROG race on the beach at Pismo Beach, CA in 2017.

hardtimes -- What Cam, Bore, Pistons, Head & CR, Est HP in the B Motor?
What is the name of the book you are talking about? Thanks for any help.

[CarlG]

Originally Posted by old28

...
hardtimes -- ...What is the name of the book you are talking about?...

4-Bangers & Me
by Jim Brierley

[old28]

Thanks CarlG Unable to find it on Amazon, other places I can try?

[Charlie Stephens]

Originally Posted by old28

Thanks CarlG Unable to find it on Amazon, other places I can try?

The author (Jim Brierley) posts here. He posted his contact information as: [email protected] or 951-695-3713 He is a good person to know.

Charlie Stephens

[hardtimes]

Originally Posted by old28

Kurt in NJ ---Thanks for the Dyno Sheet tests. A lot of information and combinations. As I start moving forward on this project I feel like a motor in the 75-90 HP range will work well for my project. I am looking at running a 28 roadster with an A motor, 39 trans & a Banjo rear end in the TROG race on the beach at Pismo Beach, CA in 2017.

hardtimes -- What Cam, Bore, Pistons, Head & CR, Est HP in the B Motor?
What is the name of the book you are talking about? Thanks for any help.

You are welcome to any info that you hopefully find helpful , as that's what this place/forum is about.
My bore is 4", pistons are Egge with special ordered compression height...that makes piston tops EVEN with top of block. Use of pistons with modern thin rings is what I did. Cam/lifters are special treat for this engine, as the lifters are Chrysler part #VL-20, what I call BIG FOOT lifters, as no lifters avail have a foot as large. In some A/B engines, this lifter has to be prepped to avoid cam, etc. But not in my B as they fit/cleared everything perfectly ! The lifter bore has to be enlarged slightly(reamed) to fit these lifters, but good news here, is that old worn out bores are made perfect again ! The CAM is a NOS B cam that I sent (lifters and cam) to Pete , senior member here. Pete is a cam expert for half century or more. Pete matched my lifters and cam profile perfectly to compliment each other with HIS special grind ! The lifters rotate amazingly well with his work ! Pete will have to know how your engine will be configured (carb(s), bore, comp ratio, etc, etc) to know which grind will make engine work well...and mine does
I happen to be lucky to have a choice of heads and comp ratios to work with, from 6:1 thru 8:1 and also an original Schofield OHV Head 6:1. originally. I've just taken off a 7:1 super Winfield alum that worked well. It now runs great with a Snyder 6:1, but I'm about to install Tod's head which I now have at near 8:1.
You will find in THE book, how to full oil Pressure your block and ,IMO, well worth the meager time/effort and $. This is a poured babbitt main and rod B block, drilled C crank with special V8 flathead oil pump (45lbs). I did custom oil pan work to keep oil available, at all times, to the pump. You will have fun doing as much as you can do yourself ! Good luck.

[hardtimes]

Originally Posted by old28

Dodge -- Do you know if a 330 or 340 camshaft will make 75+ HP? New to this forum, who is Tod"s Heads?

hardtimes -- That good news on the exhaust. Do you have a intake size in mind for my
HP range.

'who is TOD's Heads'
Tod is a senior member here and a maker of 'things extraordinary' ! He builds stuff (Heads and Blocks) for us A/B guys , blocks for V8 racers and stuff for others in industry ! Read all back threads with Tod name, including recent threads about the Newly minted crowfoot flathead on the B engine pictured below. You can contact Tod , if so inclined, for his products/heads. I've done some 'field testing' on the pictured Winfield (red) Crowfoot and that is in the threads for you to read/know
One head pic is from Tod at about 6:1. Other pic of same head now at approx. 8:1cr.

[old28]

hardtimes -- Thank you for the extra information on your motor. This A/B stuff is all new to me after 40 years of front motor drag racing with BBC engine. I have always built my own motor so I look forward to doing an A unit in the future.
Do you feel (IYO) that this motor at around 85-90 HP and 6.5 or a bit more CR will hold up with poured rods & mains in 1/8 mile drag racing on the sand with street tires. Really don,t want to go to the high dollar insert rods & main. I read a bunch of Tod's posts that are on the forum, very good stuff. I will cal on the book so I can continue on my learning program. Better to get it right the first time as parts are no cheep.

[CarlG]

Originally Posted by old28

Thanks CarlG Unable to find it on Amazon, other places I can try?

Send him a PM here on the Ford Barn.

[PC/SR]

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Poured babbitt rods and mains will handle 85-90 hp up to about 4000 rpm without full pressure oil. I have babbitt in an A block with more HP than that, do hillclimbs with no probs, have stock oil except for pressure center main and opened up the stock oil pump and a full flow filter. The key up in that HP range is ports and cam. Agree with Hardtimes no need to increase the exhaust valve size.

[hardtimes]

Originally Posted by old28

hardtimes -- Thank you for the extra information on your motor. This A/B stuff is all new to me after 40 years of front motor drag racing with BBC engine. I have always built my own motor so I look forward to doing an A unit in the future.
Do you feel (IYO) that this motor at around 85-90 HP and 6.5 or a bit more CR will hold up with poured rods & mains in 1/8 mile drag racing on the sand with street tires. Really don,t want to go to the high dollar insert rods & main. I read a bunch of Tod's posts that are on the forum, very good stuff. I will cal on the book so I can continue on my learning program. Better to get it right the first time as parts are no cheep.

Pay attn. to PC/SR has said, as good info, indeed ! My intakes are 1.75 which seem to fit well in the B block. No matter which block you use....use CAUTION when porting or having porting work done. Smoothing out is GOOD, but taking tooo much where there ain't much, can lead into water ! Since you are an experienced drag guy, your questions make more and good sense now ! When you contact Mr. (B block ) Brierley, ask him the same question....i.e.-poured mains/rods and using to drag race. Jim has maybe gone as fast on salt with B banger, as you have on strip with BBC ! Also , on drag strips with banger, when most here weren't, or were pups ! His book WILL save you time and $, but he seems very available to answer/clarify for those of us who need pictures, eh

Contact Tod for possible 6.5 head info, as he is the 'maker' of stuff.
And, as said priorly...full oil pressure is the A/B friend.

[old28]

PC/SR --- I think that any time and money spent on a full flow pressure oil system will pay back well. Any advantage in back cut stainless valves? I will go with 1.75 intake and stock exhaust. As I ran a dual 94 carb setup on my last 194" Chevy 6 cylinder dragster I will run the same setup on this A motor with a home built intake. That is good news to the pocket book on the HP/Babbitt combination. I think the A & B motor are a lot like some 6 cylinder as they like a little port & polish, and HP is all about intake, air flow & cams.

I have not been on this site until now. I have spent years over on the HAMB site and have build thread of my last 50's style 6 cylinder dragster http://www.jalopyjournal.com/forum/t...thread.603598/. Lots of good information & good people on the HAMB. I feel right at home on the FORD Barn and have got a lot of fine information, I am one of the guys that for sure does not have any background with A motors and will ask questions until I think I am ready to test the waters on a build.

hardtimes --- I agree with all you said and full oil pressure setup will be in the motor. I ran a Blowen/Alcohol 502 BBC in my N/E-1 dragster and off the index (7.50) my wife has ran [email protected] and I am sure Jims B would put us to shame. Cubic Inches ain't every thing as we had a 292"+ 6 cylinder dragster in the class that ran the same 7.50 index and was very competative. It aways comes back to the old saying (SPEED COST MONEY, HOW MUCH YOU GOT). At a young 69 I want to play in a new sand pile. I think this will be very rewarding.

[hardtimes]

Originally Posted by old28

PC/SR --- I think that any time and money spent on a full flow pressure oil system will pay back well. Any advantage in back cut stainless valves? I will go with 1.75 intake and stock exhaust. As I ran a dual 94 carb setup on my last 194" Chevy 6 cylinder dragster I will run the same setup on this A motor with a home built intake. That is good news to the pocket book on the HP/Babbitt combination. I think the A & B motor are a lot like some 6 cylinder as they like a little port & polish, and HP is all about intake, air flow & cams.

I have not been on this site until now. I have spent years over on the HAMB site and have build thread of my last 50's style 6 cylinder dragster http://www.jalopyjournal.com/forum/t...thread.603598/. Lots of good information & good people on the HAMB. I feel right at home on the FORD Barn and have got a lot of fine information, I am one of the guys that for sure does not have any background with A motors and will ask questions until I think I am ready to test the waters on a build.

hardtimes --- I agree with all you said and full oil pressure setup will be in the motor. I ran a Blowen/Alcohol 502 BBC in my N/E-1 dragster and off the index (7.50) my wife has ran [email protected] and I am sure Jims B would put us to shame. Cubic Inches ain't every thing as we had a 292"+ 6 cylinder dragster in the class that ran the same 7.50 index and was very competative. It aways comes back to the old saying (SPEED COST MONEY, HOW MUCH YOU GOT). At a young 69 I want to play in a new sand pile. I think this will be very rewarding.

Well, I did not mention a LOT of 'things' done with my new B. But, you have hit upon one of these things. My stainless valves are cut tulip shape/back cut, to encourage best flow.
IMO, if you are going for HARD work from your A/B, besides full flow oil/filtered, balancing is real important. I've just installed a custom crank balancer on my older B (in roadster) and since it was finely balanced when built, I'm expecting more longevity from the new C drilled crank that I use. I know guys who have broken their cranks/engines....until they put a balancer on the nose of their crank.
You in Bakersfield ? 100 mi away, or I'd like to help you. You guys have too much fun up there. I hear that you are having swap meet this Friday/Saturday, is that true ? Along with antique nationals

[old28]

hardtimes -- Sorry for that, I have moved back to Camarillo, the city I worked at for 35 years. We moved back last June and i had not been on this site for a long time. As I am just getting all my facts in order it will be a while before any building is started. I will let you know. Where are you located?
The A & B are a lot like the Chevy 6 when it comes to balancers. Lots of 194 & 250 that have been built up a little will brake a crank or mess up main and rod bearing for need of a balancer. Nice thing was that you could install a nutral SBC unit with only a little work and cost.
Don't know about the swap meet, but a few years ago the Model A club had a big meet at the fairgrounds in Bakersfield and they had a great swap meet.

[hardtimes]

Originally Posted by old28

hardtimes -- Sorry for that, I have moved back to Camarillo, the city I worked at for 35 years. We moved back last June and i had not been on this site for a long time. As I am just getting all my facts in order it will be a while before any building is started. I will let you know. Where are you located?
The A & B are a lot like the Chevy 6 when it comes to balancers. Lots of 194 & 250 that have been built up a little will brake a crank or mess up main and rod bearing for need of a balancer. Nice thing was that you could install a nutral SBC unit with only a little work and cost.
Don't know about the swap meet, but a few years ago the Model A club had a big meet at the fairgrounds in Bakersfield and they had a great swap meet.

Located in SFV, westerly end.

[old28]

Only a 25 min trip if traffic is moving or an hour and a half at rush hour. When I get some parts on site I would love to have you take a look & set me in the right direction. Thanks for the offer, your good people on this site as on the HAMB.

Any one know where I might find a stock 28-31 Model A frame for cheep?
A boxed frame would be a plus.
Will be installing an A motor & banjo rear end with closed drive line.

[old28]

PC/SR -- I have been reading everything I can dig up on A & B motor and I would like to pass a few things your way if I can. I am leaning to a motor set up this way for a TROG car for the hard pack 1/8 mile sand drags at Pismo Beach in 2017.

All others please jump in as I want to get input from as many builders as I can.

Car will weigh between 2500 - 3000 #'s
Street tires only, 4.11 or 4.56 rear gears
A motor Babbitt bearings, pressure center main oiling.
Bore - 4" (.125 over), 7.1 head, Stipe Windfield Full race Cam (mid to top end)
Mill .060 to .075 of head to reduce chamber size & help increase CR.
1.70 intake, fabricated 2x2 or 2x3 intake W/94 carbs
Run a 1939 Top Loader trans.
I will balance the whole rotating assembly
Lighten the fly wheel & run an 9" clutch
Hope to make 95 - 100 HP

This motor will be raced only two weekend per year, about 20 1/8 passes and the build is for TROG racing only.

[PC/SR]

Basically sounds good to me. Some random thoughts. Without pressure oil you are limited to about 4k rpm or a bit over if the line is close and you do not want to shift. (4k is the conventional wisdom for peak rpm anyway. Have never seen it documented and have not had the inclination to go faster and test it.)
Nor have I run on sand, so cannot really comment on the rear axle ratios, but I tend to think the 4.56 may run out of rpms fairly quick, even if the sand slows you down. Talking to TROG racers would be more help on that. You might think about using the '38 transmission gearset, which has higher ratios than the '39 and let you last a little longer before the shift. Check the Van Pelt transmission website for specs on the ratios.
Ports were mentioned above. The A's can be opened up.
Don't know the specs on that Stipe cam but again, you do not need a cam that peaks out much over 4k. It's not a Bonneville motor and you do not need a BV cam that peaks way higher. Check with Stipe on that and get his thoughts. Get Dan McEachern metal cam gears. Watch the clearance between the cam and crank gears. .003-.004.
If you plan to mill the head, first check the piston clearance. A friend milled head once and then had to have the piston tops milled for clearance. Measure before spending money on that.
Two 94's will work for 100 hp.
Spend time with Jim Brierely's book.
Good luck. I wanted to get in that race, but my speedster body style does not meet their requirements.

[Jim Brierley]

P/C, Hate to tell you this but '38 and '39 V8 gears are the same eatio, only the syncro was improved. Zephyr gears are a different story.

[Jim Brierley]

p.s., I've now sold over 1,000 books, partly due to the guys on this forum. That doesn't include the one old28 just bought!

[old28]

PC/SR -- I ordered Jim's book, will be here next week. Then I get down to some serious reading & learning.
How much piston clearance would you want for a motor that may be right at 4000 RPM at the finish? I have taken note of the other item's you put out there.
I am surprised that your speedster body (if 1934 or older) would not be OK as they have some belly tank racers that are not OEM bodys. I will be there this year to take pictures, ask questions and learn.

[hardtimes]

Originally Posted by forever4

Tax returns are due Monday, April 18. Don't forget to update yours.

Ha, ha...funny , but true
Ya know how when 'family' shows up when a guy is perceived as being rich ? Well, I heard this rumor that his uncle, spam/sam/something or other..is looking for him...

[PC/SR]

Jim B: I always defer to your knowledge, wisdom, experience and expertise, not to mention deference to my elders. I am now running the 28 tooth cluster with the 2.82 1st gear, which I understand was standard in '38(and meant as a possibility for Old28) as opposed to the 29 tooth cluster with the 3.11 first gear, which I understand was standard on '39s. However, as I thumb through Van Pelt's book, it looks like you might get both of these both years. (http://www.vanpeltsales.com/FH_web/f...gearratios.htm his book is more detailed.) If I find anything more definitive I will email it down.

Old28: I would not go less than .045 piston clearance with a 3 bearing A crank, but as noted above, would defer to Mr. Brierely. I have heard some guys go under .045. I use .050 myself. Also, if you are building the trans or changing parts, you need Van Pelts book, because these parts are generally interchangable but there are tricks and variations. (My speedster body is not a stock or period creation, hence not elgible for TROC.)

[hardtimes]

Originally Posted by PC/SR

Jim B: I always defer to your knowledge, wisdom, experience and expertise, not to mention deference to my elders. I am now running the 28 tooth cluster with the 2.82 1st gear, which I understand was standard in '38(and meant as a possibility for Old28) as opposed to the 29 tooth cluster with the 3.11 first gear, which I understand was standard on '39s. However, as I thumb through Van Pelt's book, it looks like you might get both of these both years. (http://www.vanpeltsales.com/FH_web/f...gearratios.htm his book is more detailed.) If I find anything more definitive I will email it down.

Old28: I would not go less than .045 piston clearance with a 3 bearing A crank, but as noted above, would defer to Mr. Brierely. I have heard some guys go under .045. I use .050 myself. Also, if you are building the trans or changing parts, you need Van Pelts book, because these parts are generally interchangable but there are tricks and variations. (My speedster body is not a stock or period creation, hence not elgible for TROC.)

Hey PC/SR,
I defer to both of you guys banger knowledge !
My thoughts are that you mean .0045 and/or .005 for piston clearance ?
Anyway, the only trans gears in the '39 era that I'm familiar with, that will give / make a difference from the trans end(i.e.-allowing higher wind up rpm), are the zephyr SECOND gear.
When combined with various rear end gear/tire ratios...I get lost as to end results

[PC/SR]

Hardtimes: I was referring to piston/head clearance, guess that was not made clear. Thanks Zephyr gear set with the 4.56 would be interesting. Yeh, lots of combinations available.

[hardtimes]

Originally Posted by PC/SR

Hardtimes: I was referring to piston/head clearance, guess that was not made clear. Thanks Zephyr gear set with the 4.56 would be interesting. Yeh, lots of combinations available.

Head clearance, got it Wow, .045 is going to be what...8:1 or better

I'm easily confused these days, eh. Did you say that I still owed you that money .
Talking gear ratios makes my grey matter hurt. I've got the better/higher zephyr 2nd ratio, but then I go to kiwi quick change rear and big tires ..and got lost

[old28]

hardtimes / PC/SR / Mr B -- Can I get 8.1 CR with 7.1 heads and a .o45 piston top clearance? Or will I have to mill the 7.1 head a bite?

Better to buy a 8.1 head and set piston top clearance to .o45?

[PC/SR]

Don't know. Depends on gasket thickness, flycut depth(or not), piston popup, combustion chamber size. Bored out will add a bit to the CR. Lots of things to think about and consider.

[hardtimes]

Originally Posted by old28

hardtimes / PC/SR / Mr B -- Can I get 8.1 CR with 7.1 heads and a .o45 piston top clearance? Or will I have to mill the 7.1 head a bite?

Better to buy a 8.1 head and set piston top clearance to .o45?

These guys will set us straight, if I say something off key !
Model A stock pistons from Ford....'popped up' about .031. So, it makes sense that you will have to have either piston head reliefs cut in the head, or piston heads which are ordered and/or cut FLAT with top of block. This keeps interference from occurring and breaking things...with flathead heads ! So, you can get a flathead head and cut the flycuts off of it (see the pictures that I showed you earlier) to increase cr, but you have to keep in mind expansion rates and things growing as rpm grow ! Now there is an exception to this , but it does not involve flathead. If you have an OHV Head with say a 'hemi' type comb chamber...now you can popup maybe lots to increase cr. With flathead, remember what PC/SR was just saying about piston clearance at .045. IMO, that is darn close...too close? Maybe

PC/SR also thinks/types faster than I do !!

[old28]

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hardtimes -- With all the information you have put out there I still have questions until I get Mr B's book. With a stock A motor are the pistons .031" above the block top at TDC? If you cut the pistons flat so the pistons meet the top of block do you have to cut Intake/Exhaust valve clearance in 6.1 head or a 7.1 head? This is for a stock motor. What if you have 1.70 Intake? Are there any 7.1 heads out there with the clearance built in that still have .050 piston clearance?

[hardtimes]

Originally Posted by old28

hardtimes -- With all the information you have put out there I still have questions until I get Mr B's book. With a stock A motor are the pistons .031" above the block top at TDC? If you cut the pistons flat so the pistons meet the top of block do you have to cut Intake/Exhaust valve clearance in 6.1 head or a 7.1 head? This is for a stock motor. What if you have 1.70 Intake? Are there any 7.1 heads out there with the clearance built in that still have .050 piston clearance?

Go back and study post #23 , the first two pictures. One picture shows head with .050 'flycuts' , above the piston heads. Other picture shows same head with flycuts removed. However, if you look at the valve pockets, you will notice that there is still plenty of depth in head to accept the biggest cam (lift) that an A will or can use. Even with the .050 cut that took away the flycuts, there is still PLENTY of valve head room...even for 1.70 intakes ! You can enlarge the valve head areas of any head to improve flow somewhat, but this head is doing such a great job driving the attached B engine, that no such enlargement work will be done or indicated as needing done.

Yes as said before, the stock Ford A engine had about .031 piston popup. You cannot run popup pistons with a head cut like the one shown.

There IS one exception to this statement though....you can run more than one head gasket or have a solid copper head gasket made to order to provide the exact piston to head clearance that you wish to have (counter-productive to have popup pistons and have to install two or more head gaskets to get clearance...shoots the heck out of cr then.

At any rate, you have to clay the piston to head clearance to determine your clearance...WITH head gasket in place. Same claying can be done with valve heads, if you want to know what you have.

Finally, answer to your last question; is there 7:1 head with clearance built in , and still have the .050 clearance ? I do not know of any This is because a 7:1 flathead IS going to look like the one pictured...without the flycuts !!
Comp ratio is a combination of a number of things. When all said and done, relative to a 7:1 flathead....the CLEARANCE (and thereby the cr) between piston top and head surface would be set by use of proper head gasket and cc of valve areas in head.

Contact Tod and tell him that you are interested in obtaining a 7:1 cr head... You will most likely be buying a head that looks like the one pictured in post #23.

[old28]

Question, With a stock piston at .031" above the top of the block with a 7013 R3 gasket & 1.70 intake valve will a standard 6.1 iron head work with no other motor modifications? Does a 7.1 iron head have to be fly cut to work in the same situation?
What's an easy way to get 75 -90 HP from an A motor with the least amount of machine work? I will port/polish the block at home and build a 2 x 2 intake with 94 carbs. Will have stock size exhaust & 1.70 intake. Looking at a 330 or 340 cam.
Just trying to get some combinations to think about.

[johnneilson]

An Old Banger Racer told me in the beginning of my exploits, "you will never spend so much money on a motor to go so slow as a Model A".
The other advice he gave, "Start with a B Model, it is half way modern".

There is a ton of opinion about heads a chambers.
I had a 8:1 Winfield repop here that would not flow enough air to make 70 hp. This is a dilemma for the side valve motors. Not to say that it cannot be done, just beware of snake oil salesmen.

[Tom Wesenberg]

Turbocharge it for the most bang for the buck.

[old28]

forever4 -- That may be true, but a smart man asks a lot of questions before he starts throwing money into a project.

johnneilson -- Well taken. As I want to increase the bore to 4" (.125 over) I was leaning towards the thicker (they say) A block. I know what you say on the oil salesman, I have read a few threads from real life conditions that said they could not see any noticeable performance between a 5.5, 6.1 or a 7.1 head. I am with you on dollors/speed on an A/B motor. I have recently built a few 6 cylinder race motors and spent twice what I did on my BBC motors to run slower.

Tom Wesenberg -- Turbo's are out as per the rules in TROG.

[johnneilson]

old28,

just think about this, 4" bore on a motor with bores on 4.250 centers. It doesn't matter A or B. I have seen 4.030 bores, not for my stuff, thank you.

IMHO, a B block with full pressure drilled crank and inserts makes sense. I know of many who have run babbit very successfully, again, not for my stuff.

The best part of this is that there isn't a catalog like Summit or Jegs to choose from, if you want to go fast, you have to massage the parts, gently.

[old28]

johnneilson -- As this motor will be for the TROG race twice a year I want to go with a big inch setup as in a 4.00" bore. I plainned on center main pressure oil & babbitt bearings (both rods & mains). As the motor will be run maybe 10 1/8 mile passes on hard sand I can't get my pocket book around full insert bearings. May change my mind before I start building, I will see what I learn in next few weeks.

I have done years and years of Summit & Jegs with my BBC dragster & altered and I am up for this new game with the A & B. Just got my copy of 4 Bangers & me from Mr B so I have a lot of reading & learning to do for the next few weeks.

[old28]

What is the compressed thickness of a Fel-pro 7013 R3 ?

What is the compressed thickness of a Best #509 ?

If I order pistons with a CH that will have my pistons even with the top of the block at TDC, Is there a head gasket that will provide .050" piston to head clearance with a 7.1 CR head with no piston fly cut?

Or do you have to set up the motor with the pistons .010 - .013 in the hole?


The more I read my book (Mr B's) the more questions I have. I am learning more each day. Hope you guys with all the right answers don't get tired of the questions from the new guy.

[PC/SR]

The Best gasket compresses to .050--.055. I run it with pistons with no popup or flycut. Be really sure to measure the deck height from the pan rail to the deck. (11.5" stock.) It is critical to calculating popup. I bought a "new" block and took the sellers word for how much he took off and got popup I did not want and the valve lengths were off. Finally measured it and it apparently someone sometime took off more, threw the initial measurements all off.

[old28]

PC/SR -- Thanks for the information. I am thinking that the FelPro-7013R3 will be the same as the best at .050-.055 compressed, but I would like to hear from someone that has used one.

So if I know the block height I can order pistons with a CH that will place the flat top piston even with the block top. Then using a 7.1 iron head with no fly cuts, install a Best 509 gasket and I should have (.050-.055) piston to head clearance. Am I correct or have I missed something?

Are Egg & Ross both good for custom pistons (CH) as I am going to use cast not forged in this Hot Street type build? Piston rings will be the small modern style type.

[old28]

With your years of Model A building knowledge go easy on use new guys that are just getting started in this A & B sand box.

As per the answer from PC/SR above I was unaware that there were two models of the Best 509.

CH -- Compression Height

At the young age of 70 this ain't my first rodeo, been building by own drag race motors for 50+ years but this A & B stuff is a new game and it's like starting over.

[old28]

forever4 -- Thanks for the information. I am working towards a hot street type motor to run in the TROG in Pismo Beach, CA. This car will make maybe (10) 1/8 mile passes on compressed sand at the beach once or twice a year. The more I read Mr B's book the more I am looking at a lower HP mark.
I think a motor for this project in the 65-75 HP @ 380-4000 RPM would work great and do what I want it to do & not have to be working on it all the time.

As this motor will only be run a few passes I would still like to build cubic inches as large as I can at 4" bore (.125" over) and with a uncut 7.1 head and a compressed gasket at (.050-.055) and the original pistons Up .031" out of the hole, how do you maintain a .045-,050 piston to head clearance?

Do you have to flycut the head in the piston area about .031" with the above setup? How much does this lower the CR on a 7.1 head?

Open to other/better ways to get to 65-75 HP. All the normal cam, intake, carb, P&P, will be done. This is not a high buck build, just a fun setup for a fun race, Ain't the Salt or the dry lakes, even thow I love them.

[Spokes]

Originally Posted by old28

Thanks CarlG Unable to find it on Amazon, other places I can try?

Jim B. is a Member on Fordbarn. I have his Book every interesting and complete. Jim is also helpful with Banger Questions. Two Great Magazines on the Subject FAST and Secrets Of Speed both have Web Sites. Hill Climbs, Meetings Ect.

[George Miller]

If you worked on drag engines for 50 years you must know about O ringing the head for stainless steel O ring. Why not do that. That is how I sealed the Olds 455 head on my Model A engine for hill climbs.

[old28]

Spokes -- Thanks for the information on the other magazines. I have Mr B's book and have just finished it, I am going to read it again and ask for as much help on this site as I can get before starting a build.

George Miller -- Ya we did a lot of BBC block o-ring to seal copper head gaskets on our blowen/alcohol nostalgia front motor dragster. This is a totally different motor and o-ringing is over the top for this project. If it looks like I can not get a good seal with the 4" (.125" over) I will see if I can run .020-.030" over bore. I want to stay with a gasket that will work with the 7.1 head I finally get.

[Spokes]

Originally Posted by old28

Thanks CarlG Unable to find it on Amazon, other places I can try?

Jim B. is a contributor on Ford Barn, He sells His Book direct. You Can contact Jim on Ford Barn. Two good groups to join. S.O.S.S Secrets Of Speed Society . .and F.A.S.T Hot For Hot Fords. They both have WEB sites, Hill Climbs stock and Members speed parts for sale . Hope This Helps !!!

[Jim Brierley]

I have my Bonneville engine O-ringed, haven't found a need for my street engines. To do a flathead it would be a lot of work.

[old28]

Jim Brierley --Thanks for jumping in. I have just finished reading your book and I will start my second pass on Thursday. Great book with tons of information. As A young old dude at 70 the more I read, the more questions I have. Group on this site has been great and are treating the new guy nice.

After reading the book I am leaning more towards a "hot Street" style motor for my future A build.This motoris is for a TROG car to race on the sand at Pismo Beach, CA once or twice a year. My first idea was to shot towards a 85-95 HP motor. After your book and talking to a lot of people on this site I think a 65-75 HP motor with a B trans with 39 gears would work out better. Motor will have all the normal High Performace things done, cam, intake, P&P, Ign,ect. I still would like to max the cubic inches with a 4" bore & stock stroke. I would like to run a Winfield 7.1 repo head. This is all in my head right know so there is lots of room for changes.

I would like to send you a PM to ask you a couple of questions on piston CH and head relation if I can. Thanks for any and all help.

[Charlie Stephens]

Originally Posted by old28

Jim Brierley --Thanks for jumping in. I have just finished reading your book and I will start my second pass on Thursday. Great book with tons of information. As A young old dude at 70 the more I read, the more questions I have. Group on this site has been great and are treating the new guy nice.

After reading the book I am leaning more towards a "hot Street" style motor for my future A build.This motoris is for a TROG car to race on the sand at Pismo Beach, CA once or twice a year. My first idea was to shot towards a 85-95 HP motor. After your book and talking to a lot of people on this site I think a 65-75 HP motor with a B trans with 39 gears would work out better. Motor will have all the normal High Performace things done, cam, intake, P&P, Ign,ect. I still would like to max the cubic inches with a 4" bore & stock stroke. I would like to run a Winfield 7.1 repo head. This is all in my head right know so there is lots of room for changes.

I would like to send you a PM to ask you a couple of questions on piston CH and head relation if I can. Thanks for any and all help.

Before I send a PM to someone I ask myself two questions, 1) Is it possible someone else would be interested in the answer and 2) Is it possible that the question/answer will generate other input from posters when they see it. This leaves me sending very few PM's.

Charlie Stephens

[johnneilson]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by George Miller

If you worked on drag engines for 50 years you must know about O ringing the head for stainless steel O ring. Why not do that. That is how I sealed the Olds 455 head on my Model A engine for hill climbs.

I see the issue of "O-Ring and or Fire Ring" mentioned here.

IMHO, full on race OHV motors will need the help, I use solid copper gaskets in this application. Putting the wire groove in on the Flat Head is a chore, it can be done. But, you are cutting into a deck that is marginally thick enough to seal a gasket. O-ringing around the bore is fine if placed properly, lots of material.

I contend that the gasket failures, some, are from the head and deck moving caused by being too thin. (this assumes deck and head are properly flat) The only FH motor I currently work on with water jacket does not have a o-ring for the gasket, instead use a BEST graphite gasket and have a sufficiently thick head that supports it. No leaks or failed gaskets.

Carry on, some good discussion here.

[George Miller]

Originally Posted by johnneilson

I see the issue of "O-Ring and or Fire Ring" mentioned here.

IMHO, full on race OHV motors will need the help, I use solid copper gaskets in this application. Putting the wire groove in on the Flat Head is a chore, it can be done. But, you are cutting into a deck that is marginally thick enough to seal a gasket. O-ringing around the bore is fine if placed properly, lots of material.

I contend that the gasket failures, some, are from the head and deck moving caused by being too thin. (this assumes deck and head are properly flat) The only FH motor I currently work on with water jacket does not have a o-ring for the gasket, instead use a BEST graphite gasket and have a sufficiently thick head that supports it. No leaks or failed gaskets.

Carry on, some good discussion here.

I agree I have never found a need on a flat head. The one time I did it was on a olds 455 head on a A engine. I had one bore to 4.030 over. at first it was running a Lion head number 6. then changed to Brumfield 7-1 never had head gasket trouble with that engine.

My 1928 sport coupe is running a 4 inch bore for 22,000 miles {knock on wood} with out blowing a gasket.

[old28]

Charlie Stephens -- I am with you on #1 & #2, but there is a number #3 that I ask myself, Has this question been asked and answered 100 times on this site and the crew does not want to hear it again

johnneilson -- What is the number of the Best Graphite gasket you are using? What head & CR?

George Miller -- As I would like to bore this motor to 4" and use the water jackets, what head gasket do you run?
Looking at a lion Head and a Winfield Repo 7.1, what say you guys? The head needs to breath good as I will be running 2x2 81's or 3x2 94's.

I want the correct gasket for the heads and block that I will not be replacing after each race weekend.

[johnneilson]

OLD28

I have no idea what the number is, the owner just has a stack of them.
As for the head, it is one I made, running about 9:1 per whistler.

J

[George Miller]

Originally Posted by old28

Charlie Stephens -- I am with you on #1 & #2, but there is a number #3 that I ask myself, Has this question been asked and answered 100 times on this site and the crew does not want to hear it again

johnneilson -- What is the number of the Best Graphite gasket you are using? What head & CR?

George Miller -- As I would like to bore this motor to 4" and use the water jackets, what head gasket do you run?
Looking at a lion Head and a Winfield Repo 7.1, what say you guys? The head needs to breath good as I will be running 2x2 81's or 3x2 94's.

I want the correct gasket for the heads and block that I will not be replacing after each race weekend.

On my sport coupe with a Brumfield head and 4 inch bore. I'm using a FEL-PRO 7013C

[old28]

johnneilson -- Had to ask

George Miller -- Thank you for the gasket numbers & head information. With the information I have posted above, would you IYO recommend a head setup that would meet my needs as I don't want to over build the motor for what it will be used for. This is all in the planning stages so fire away.

[old28]

hardtimes -- Just want to get this clear, we talked about it before.

If I run a motor with a flat top piston even with the top of the block, have a compressed gasket of .050" and run one of Tod's crow foot iron heads with no piston index cut into the head, will the CR be at or near 7.1?

[hardtimes]

Originally Posted by old28

hardtimes -- Just want to get this clear, we talked about it before.

If I run a motor with a flat top piston even with the top of the block, have a compressed gasket of .050" and run one of Tod's crow foot iron heads with no piston index cut into the head, will the CR be at or near 7.1?

IMO, given YOUR statements above, the cr of this setup will be between 7:1 and 8:1 cr ! Look my pictures over again. The one pic , without flycut, is what you can have from Tod.

To get exact cr, you will have to do exact calculations, i.e.-bore;stroke;cc of head chambers;gasket compressed. Being an amateur math man, I 'guesstimate' everything in life. Hey, I'm guessing that I'm only wrong 50% of the time


(note here: There is a chart concerning gasket cc, when calculating...I use the 20cc figure that is used by a famous racer member here)

Again, my opinion: This Crowfoot Iron Head from Tod ('Buttermore Special' ) has THICKER surface , so that you can order with flycut and with some WORK, do install/testing/shaving/install/testing/shaving...till you get what YOU feel is best. Or you can calculate and go for 'best' on first assembly , your choice..and choice is good, eh .
Using old/worn Iron heads is felt to be 'cool' looking and impresses the boys. However, IMO, decades of rust scale and milling/repairs (now throw in poor torqueing practices) makes these same heads primary function (no flexing firm clamping to block) lessened. That is a primary reason for leaks/blowouts/cracking, IMO.

Whereas, along comes a NEWLY made thicker (in the right areas) iron flathead (Tod's Crowfoot), which eliminates/minimizes such problems...let me think which one should I use...

George gave you gasket info that has worked for him. Also, Best 509 has worked somewhat for 4", but NOT many at all to choose from that will PROPERLY FIT THE 4" BORE AND BIG VALVES !!

I have one made to handle 4" bore and it is NOS Cunningham, maybe only one left on earth ! That's why I'm saving it as is... ..it's a poor boy syndrome thing most wouldn't understand.

IS THAT CLEAR..as mud !!

[old28]

hardtimes -- That's a lot of information to mill around in this old head

It is a great "NEW" head that is thicker in all the right places. I ain't trying to impress anyone with the looks, just want the best iron head I can get for my project.

[johnneilson]

One thing to consider, there has been talk of the practice of using two head gaskets on these motors to "make" piston clearance.

IMHO, it is going to cause more problems. Not only does it provide one more place to leak, it will lead to more deflection in the deck and head resulting in more potential for leaking in the future. (clamping down on a soft surface allowing the deflection)

As with any info provided here by me, it is my opinion. I am sure that many others will disagree, those are your opinions.

J

[hardtimes]

Originally Posted by forever4

It is also a poor boy syndrome to save used head gaskets, in case you might need it someday.

If I had an example of the typical big valve, I could put it in a block and evaluate all the gaskets against it and add that info to the rating guide.

Is there a particular parts store big valve everyone uses which has a 5/16" stem?

click> Model A & B Cylinder Head Gasket Guide on Ford Garage

Hey Vince,
At least I didn't tell them where the Cunningham 4" bore gasket came from...ha, that guy might get mob email for same !

Regarding valves source, in the new B , I think that the stems were 11/32" chev keepers/retainers. The valves were new chev big bore 1.75" ..stainless, all exhaust. However, in my case, I used V8 flathead valve springs (75lbs seat pressure) and Chrysler lifters.
It was necessary to shorten the valve stems somewhat due to height of lifters. So , new keeper notches cut into stems for what seat pressure wanted.
Many yrs ago, used sbc exhaust valves for all new B block build.

[old28]

Thanks guys, all good stuff.

I ran dual copper head gaskets on my blown/alcohol BBC a few times as we were in a bind, Not the way to go, but when your racing you do what you have to & with what you have at the track.

[old28]

hardtimes -- If I use Snyder's .040/.060 over size replacement pistons with stock A rods and crank, the piston will be above the deck .031". If I have a compressed head gasket at .055", that leaves .024" clearance. If I want to run .050" head to piston clearance, does this mean I have to fly cut the head on Tods crow foot in the piston area about .026"? I know that all measurements would need to be exact at time of build.

How much CR would be lost?

App cost of the pistons you purchased from Egge with a higher CH so you could get a -0- piston/deck?

I am looking for a solid 7.2 CR setup.

After reading Mr. B's book twice I am leaning more towards a 60/70 HP motor with a 20/30/40/60 cleanup bore.

[Tom Wesenberg]

"How much CR would be lost?"

If Tod's head compression ratio is based on .050" clearance, then you will have the same ratio if you need to have pistons made to that clearance, or the head flycut.

[George Miller]

Originally Posted by forever4

It is also a poor boy syndrome to save used head gaskets, in case you might need it someday.

If I had an example of the typical big valve, I could put it in a block and evaluate all the gaskets against it and add that info to the rating guide.

Is there a particular parts store big valve everyone uses which has a 5/16" stem?

click> Model A & B Cylinder Head Gasket Guide on Ford Garage

I use a 235 chev intake and turn the head to 1.750 dia. exhaust I use the 235 exhaust as is. For the valve guides I used 11/32 ones from a International tractor.
You can now buy guides from model A parts suppliers. You will have to shim the springs or use different ones, to get enough spring pressure. I also reamed out original guides one time to 11/32.

[old28]

Tom Wesenberg & George Miller -- Thanks for the information to help me get my all this new stuff in a row. I am just finishing Van Pelts book on transmissions along with my 3rd pass on Mr B book, still finding more stuff each pass.

[old28]

What is the CFM on a 97 & 81 Carb?

I have always used 94 carbs that flow 150 cfm, are 97 & 81 a better choice for the motor build I am planning?

Motor build is listed in this thread.

I want to use 2x2's or 3x2's setup.

[old28]

What color of dark green can I paint my A engine? Not looking for a restore color just one that looks nice and can be brushed on. Want the same color on pan, block & iron head.

[KenCoupe]

The Ford engine green paint is available from most of the usual Model A vendors. It comes in both a pint can and spray rattle can.

[Charlie Stephens]

Originally Posted by forever4

Umm? How about Ford engine green?
Is there a better, easier, more obvious choice?

I would use Ford engine green on the cast iron parts but I would use black on the pan out of respect to Henry.

Charlie Stephens

[old28]

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OK I get it, Ford Green LOL

Is there one brand that holds up better?

The pan will be "BLACK"

[Chris Haynes]

Speed costs money. How fast do you want to go?

[old28]

Chris --- Already went fast & spent a ton of cash.

This is about the build & having a project to work on.

[old28]

Just got my model A motor and have started to pull it apart. I do have a question on the valve train side cover. I have seen a few cast aluminum side covers that are not set up to use the stock oil return tube on the side. my motor has a small hole in the case at the front that returns oil to the front of the cam bearing.

As this motor will be used for 1/8 mile sand (Trog) racing only with limited run time, will it be ok to run a none return oil tube side cover?

[colin1928]

Yes it has been done before

[old28]

colin1928 -- Thanks for the reply. Good to hear, I was hoping that was the case as this will be a fresh built motor and should not be using more oil than normal for regular lubrication. I would like to run a 5 or 6 rib cast aluminum side cover. If I find one that is setup for the oil tube I will run it.

[TBone69]

Hey old28 how did the engine build come out? I stumbled upon the thread looking for piston to bore clearances.

I'm in NJ and building for TROG 2018, I've been a spectator for far too long.