Cam Tech

[frnkeore]

I thought I'd start a new thread on cams for the V8, rather than add more to the other thread. But, this will apply to all engines, including, OHV and the L head 6.

There is a lot to cam selection and there are many cams to choose from. Even though the cam is the heart of a engine, the cam can't do everything for a engine. It can only allow the port to try to fill the cylinder, with fuel and air.

The V8's biggest problem is the port. It's way to small for any serious HP. The stock diameter of it, is 1.312". It takes a LOT of porting to just enlarge it to 1.38.

I don't know the specifics of the porting work, of the flow test I'm posting but, it has 1.6 valves and is the only test that I've been able to find It seems to have been done in the best way possible for the V8.

144 cfm, isn't very much flow, at all. A OHV SBF with aluminum heads, can flow double that, w/o a problem. A well designed OHV port, can deliver 2 - 2.2 HP per cfm, for a V8. It is my opinion, that the flathead V8, can only deliver 1.4 - 1.6 HP per cfm and that is regardless of how many CI it has. If it was a OHV engine, that 144 cfm, would only get you 288 - 317 HP max, regardless of the displacement.

Does anyone else have any flow tests for a stock or ported engine? As a guess, I think a stock port, would be in the 110 - 120 cfm range, with a good valve job.

The cfm flow, works with the displacement. It takes more duration to fill a larger cylinder than a smaller one hence, the reason why one cam can't work, with all engines. So, it takes more duration to completely fill a larger cylinder.

HP, is a product of BTU's and BTU is a product of how much air and fuel, your able to burn.

A engine is a air pump and will produce so much air per revolution. The bigger the cyl, the more air but, if you spin a smaller cyl, at a higher rpm, you can attain the same volume as a bigger cyl. BUT, in either case, you have to have a hole, big enough to allow the cyl to fill so, the port is the limiting factor on HP. The undulations that a L head has, limit flow, so the flathead, can never keep up, with a OHV engine.

I have a lot of detailed cam info to post on old and currently available cams but, I can't add the L100 to the comparisons, w/o the advertised or the .015 cam lift duration. I have the .050 info and lift but, I need the .015, seat to seat or advertised duration to do it. Can anyone help with that?

I also will be posting a way to, advance and retard a cam, accurately.

More to come.

[JWL]

I have done hundreds of flow tests with various port/head/relief configurations. Your numbers are strong representatives. It is allot of work to get 150CFM @ 28". There is a point at which the valve can be completely removed and no flow increase detected. Without finding my records I seem to recall the stock flows to max out at 90 CFM. If I get in the mood I will try to find my notebook.

[Ol' Ron]

Yes, I've been working on a new port for the past few years and came up with a method of removing the bowl under the valve to eliminate turbulence at hi flow. unfortunately my flow bench is long gone. i'm now working on improving the port. An interesting cylinder head is the 96 chevy smaller valves greater flow more HP????? The block is 258ci.
Gramps

[Tim Ayers]

Originally Posted by Ol' Ron

Yes, I've been working on a new port for the past few years and came up with a method of removing the bowl under the valve to eliminate turbulence at hi flow. unfortunately my flow bench is long gone. i'm now working on improving the port. An interesting cylinder head is the 96 chevy smaller valves greater flow more HP????? The block is 258ci.
Gramps

LS series motors use smaller valves I believe. Totally different animal than a flathead, but...

[vincent]

On a Vincent motorcycle you gain 3 hp when the exhaust valves are 1/8 smaller ...

[Ol' Ron]

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Tim, sometimes you have to look outside the box, nover know what you'll find. I'm sour someone had tried EVERTHING to improve the flathead. I look at JWL's input and say. "Good idea". At my age I can only wonder id we missed something. So I came up with a "BOWL" remover. Will it work?? I don't know?? might, might not. I'll post a picture of it and when the engine is done we can dyno the engine and find out??
Gramps
PS Fantastic information here, Makes that 200 hp flathead even harder to find.
G

[Tim Ayers]

Originally Posted by Ol' Ron

Tim, sometimes you have to look outside the box, nover know what you'll find. I'm sour someone had tried EVERTHING to improve the flathead. I look at JWL's input and say. "Good idea". At my age I can only wonder id we missed something. So I came up with a "BOWL" remover. Will it work?? I don't know?? might, might not. I'll post a picture of it and when the engine is done we can dyno the engine and find out??
Gramps
PS Fantastic information here, Makes that 200 hp flathead even harder to find.
G

Totally agree. When you look at science breakthroughs, a lot of advancements came by numerous attempts at improvements or going against the norms.

[Ronnieroadster]

Frank there's a small group of like minded serious flathead Ford V-8 power producing guys. Each of us never accepted the idea The V8's biggest problem is the port. It's way to small for any serious HP. Now serious horsepower means different things to different people.

First I realize to the purist having 85 to 110 HP is more than enough. Then there's the guys who are happy with the thoughts of 150 to 200 HP. Then there's the forced induction crowd who expect 225 to 300HP the last two groups I'm part of for sure.

Then there's the small group I referenced to at the beginning who expect and get well above the 350 HP range. Some of us still use the original port layout of the production block I fall into that category.

I can't add anything to your port flow numbers since I have never taken the time to flow my ports. However I'm interested in the numbers you posted and anything else you add. If I can locate anyone in my area whos willing to work with me on testing ports maybe I can add something in the future.
Ronnieroadster

[40 Deluxe]

Some bench racing thoughts, if I may: Flow benches measure a steady flow of air, BUT it does not work that way in a real engine. Every time the intake valve closes, airflow completely stops at the underside of the valve and stays stopped during the compression, power and exhaust strokes. Since air has weight, it also has inertia and continues flowing into the port from the intake manifold and "piles up" behind the intake valve. These changes in velocity and pressure of the air/fuel mixture cause reverse pressure waves to travel back up the port into the intake manifold. Then the intake valve opens and the mixture behind the valve has to accelerate from a dead stop to enter the cylinder. Remember, the mixture is never "pulled" into the cylinder, it is always "pushed" in by atmospheric pressure (the air entering the carb).
Question #1: How much does this "start-stop" phenomenon of air flow affect the CFM readings of the flow bench?
Question #2: Is it better to enlarge the bowl as much as possible to "store" the incoming mixture until the valve opens, or better to shape the bowl to maximize flow once the mixture begins moving? (Probably some of both).

[Ol' Ron]

40 Deluxe, I think you have a good reason to believe this. I have the same feeling and for years felt the same way, however, one engine i built over 1400 miles by phone, made me think I might be wrong. The engine was that of Richard Koncs. AS his engine was going together, he asked about the ports?? I said, for your application I said "forget about it "
Several years later I had a chance to drive it. 276, l-100, hcheads and 500cfm carb and stock ports and valves. Y-5/4.10.
Bought the revs up, dumpt the clutch, poundes second. And the 3800 lb car supprised the sh#@ out of me.. 5 grand aall the way,
Not bad for stock valves and ports.
Gramps

[outlaw]

Thanks for starting this thread! I love it when you guys start talking engine mods, especially cams & I try to absorb all the information!

[frnkeore]

I really know nothing about how to port a flathead. All I know is that you do not have much to work with! The 1.312 factory port is very limited, even to how large to can take it. I would be surprised if you can safety enlarge it to 1.44. There is water above it. The radius of the port, doesn't lend itself to being able to even see what your doing and getting 8 ports the same...... good luck.

I do believe you can work the bowl and valve guild area, successfully, that and a good 5 angle, valve job will increase flow but, by how much, I can't say.

There are many talented people in high performance engine building but, since the end of the '60's, not many of them work with the FH. If this engine were still popular in racing, I think port work, would have advanced to much higher level. The more minds, the more advancement.

In addition to what 40 Deluxe brings up, there is also overlap that has to be dealt with. Some amount of overlap is good, as it continues to draw on the intake port at higher rpm but, I suspect it's less desirable on a L-head engine. Here is where a dyno would be most helpful.

Regarding lift, it isn't needed much for the V8 and can have negative results if, after some point, the flow becomes turbulent. If it doesn't, even if the flow stops increasing, you'll still get more "area under the curve", with the higher lift.

Increased compression, will always create more HP, if you can get it. That is also hard to come by, on these engines. I spoke before about, what is called dynamic compress ratio, it the actual compression event, after the intake valve closes. Static compress ratio, as we all know, is the difference between the cyl volume and the cyl head volume but, that cyl leaks, until the intake is fully closed. The charts are increase duration, L to R. Note the LSA, ICL and overlap.

In the charts I'm posting all the engine sizes are the same, 3 5/16 x 4.0 (275.69 ci) and all static C/R are 8.70.

I would also, like I said earlier, like to do the L100 cam and if I can get that info, I'll also post the HV 12 cam (I have the specs for it) and some other lower duration cams.

Thank you all for your input, especially John and Ronnie.

Tomorrow, I'll explain a way to advance and retard a cam, accurately.

[Ronnieroadster]

Originally Posted by 40 Deluxe

Some bench racing thoughts, if I may: Flow benches measure a steady flow of air, BUT it does not work that way in a real engine. Every time the intake valve closes, airflow completely stops at the underside of the valve and stays stopped during the compression, power and exhaust strokes. Since air has weight, it also has inertia and continues flowing into the port from the intake manifold and "piles up" behind the intake valve. These changes in velocity and pressure of the air/fuel mixture cause reverse pressure waves to travel back up the port into the intake manifold. Then the intake valve opens and the mixture behind the valve has to accelerate from a dead stop to enter the cylinder. Remember, the mixture is never "pulled" into the cylinder, it is always "pushed" in by atmospheric pressure (the air entering the carb).
Question #1: How much does this "start-stop" phenomenon of air flow affect the CFM readings of the flow bench?
Question #2: Is it better to enlarge the bowl as much as possible to "store" the incoming mixture until the valve opens, or better to shape the bowl to maximize flow once the mixture begins moving? (Probably some of both).

Your correct in the idea of the valve being closed has now created in a way a reverse flow situation. In a performance application the intake manifold design can take advantage of this reverse velocity so you now gain increased port flow. The Tunnel Ram design is the solution.
Ronnieroadster

[Ol' Ron]

where do we get one of those?? What doz it look like???

[Ronnieroadster]

Originally Posted by Ol' Ron

where do we get one of those?? What doz it look like???

Ron I think this is what your asking about. Limited production so far.
Ronnieroadster

[Tim Ayers]

Originally Posted by Ronnieroadster

Ron I think this is what your asking about. Limited production so far.
Ronnieroadster

I believe Mike Davidson from Australia was making a base intake that takes the 1 X 4 or 2 X 4 top of an Offy tunnel ram. According to Mike's data, it worked very well.

[glennpm]

Tunnel ram design

[frnkeore]

This is a attempt to enlarge the smaller text.

[glennpm]

Larger text

[frnkeore]

That didn't seem to work, if anyone would like full size copies, give me your Email and I'll send them.

[Ol' Ron]

I built something lik that 25 years ago, and I still have it.. Gota get an grand kid over here so I can post somepics.
Gramps
PS this one is much nicer tho.
G

[Flathead]

Are the port flows mentioned here done with or without a head in place?

[Elmo Rodge]

I think I attached a photo of my injectors.
Wayno

[Elmo Rodge]

This plays to the tunnel ram idea. This is Flat32s design and I went 189 m/ph at Bonneville on gasoline 2 months ago.
Wayno

[Ol' Ron]

Atta boy Wayno. Sure miss those Bville days. Stay safe
Gramps

[Bored&Stroked]

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Originally Posted by Elmo Rodge

This plays to the tunnel ram idea. This is Flat32s design and I went 189 m/ph at Bonneville on gasoline 2 months ago.
Wayno

I think you need to add dual plenums on top (one for each side) and a pair of appropriately sized turbos . . . throw the boost too it Wayno!

Hope all is well with you - looking forward to seeing you at BVille once again. I'm just now going through the FlatCad engine to determine our next plans for an upcoming BVille build. We have lots to do, hopefully we can get er' done! Have a great Holiday Season.

[frnkeore]

Originally Posted by Flathead

Are the port flows mentioned here done with or without a head in place?

It says in the one I posted, that it has very thing but the piston.

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First, before I forget it. It looks like the cam blanks that Comp Cam uses, are on 107 LSA, for those looking for tighter than 111/110 lobe centers to start their grinding on.

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So, how do we make a adjustable timing gear.........

I'm posting a picture of the front of the cam and a aluminum timing gear so, you can see what we are dealing with, also a set of 1/2" bushings I made years ago, for a different application.

First, you will need a lathe and milling machine to do this accurately. Your going to be moving the cam by degrees. The radius of the bolt circle, is 1.06 so, each degree will be .0185 and the max you will be able to move it, will be +/- 5°.

I would suggest making the bushings first, using 1/2" round stock. I would use steel but, I think aluminum would work, too.

Part it off at .180 +/- .005. Then holding them in a collect or boring soft jaws in a vise, Drill and ream .310 (to be a close fit on a 5/16 bolt), first one on center, then as many as you want/need, off center, for your application, in multiples or fractions of that number (.0185). 5° is .0925 and the max, before breaking threw the edge of the bushing.


Using a good drill press or mill (square to the table), drill the offset hole (circled in the picture) to 15/32 and then ream it with a 1/2" reamer. You need a rotary table or CNC machine next.

Set up a 2.623/2.6245 spud in the center of the rotary table, D&T a 3/8 or 1/2 hole, in the center, for a hold down washer no larger than 1 3/4 dia. Then, D&T a 5/16 hole at "0" 1.06 off center, on the rotary tables scale. Bolt the timing gear down, with that bolt, install your center hold down and take the bolt out. Then machine +/- 5.5° (for a little clearance), both sides 0, then both sides of 90° on either side of that. The slots should be at least .330 wide. Finally you will need to make a washer that spans the 1/2" reamed hole, for even pressure in the 4 locations.

From there, degree your cam in with the 0 bushing, then install the off set bushing that best matches where you want the ICL to be.

I have NOT done this, myself. For those that want to do this, please give us some feed back as to anything I may have over looked. This is all done based on my timing gear and the Ford cam drawing.

[Tim Ayers]

Epic thread...

[Pete]

The offset bushing method that Frank describes is a very good way to adjust the cam and I have used it many times on OHV engines.
However, on flatheads as long as there are early press-on gear cores available, they are much easier and CHEAPER to use. You just press the gear off, move it and press it back on. If you do the adjusting with only one cylinder mocked up, the process goes quickly.
The straight cut performance gears are available in press-on also.

[Elmo Rodge]

This is the completed plenum.

[frnkeore]

Here are some more. The 21 stud cam timing and the pre '49. Again all the specs are the same for all the engines and 8.70 C/R.

Note that the early 21 stud, has the same lift (.292) but, a lot more duration. Has any one tried it as a replacement for the later cam? If so, how was it?

I'm also including specs for what Comp Cam sells. I did the smallest "Thumper" on one of the other charts. No one ever talks about these. They would be pretty good if you took about 20° out of the exhaust advertised duration and 6° out of the .050.

[Ol' Ron]

During my stock car days, we just slotted the bolt holes, moved the cam where we wanted it. Placed star washers under the bolts and went racing. Never had a problem. However, after a few years, I discovered that the air pressure in the right front was more important than the cam timing.
Gramps

[outlaw]

Frank, this last chart set came out larger & prints out good on my copier. Thank you.

[tubman]

Originally Posted by Ol' Ron

During my stock car days, we just slotted the bolt holes, moved the cam where we wanted it. Placed star washers under the bolts and went racing. Never had a problem. However, after a few years, I discovered that the air pressure in the right front was more important than the cam timing.
Gramps

Yep! When I was racing, the most important item was the logbook that had the initial gears, stagger, and tire pressures to use when running on the many different tracks we encountered.

[Ol' Ron]

I would expect that Bonneville engines have to be perfect to atain the record breaking speeds. Circle track has too many variables. However, I'm sure the timing is one of them!!

[frnkeore]

Originally Posted by outlaw

Frank, this last chart set came out larger & prints out good on my copier. Thank you.

I don't know why but, even though I do everything in the same format to post, the more charts I post, the smaller they get on the forum?

I would still like to get the Advertised or Seat to Seat timing for the L100 cam, if anyone here has that info, it would be appreciated.

[Zeke3]

Frnkeore, thanks for starting this thread, it is very interesting. What calculator are you using, is it one you created?

[frnkeore]

Originally Posted by Zeke3

Frnkeore, thanks for starting this thread, it is very interesting. What calculator are you using, is it one you created?

It is a Pat Kelly program. Search his name with dynamic calculator and it should bring it up.

As promised, I did charts on the L100 and the H-V 12. The info I have on the H-V 12, is that it is a '36-'37 cam and no lift info. I'd say that it would be under .330 lift, from that time period.

Well, Ronnie was gracious enough to give me the seat to seat timing of the L100 off one of his cam cards. Thank you Ronnie!

I like the 108 LSA and the ICL of 104. I had wondered if that combination would work on the V8. It is what has been used on higher rpm, OHV engines for a long time and I like a narrower LSA.

The info that I had gleaned, off this forum, regarding the L100, is a bit different. They only had the .050 timing and .375 lift but, there sims to be several LSA's. There seems to be 4 (5 including Ronnie's) variations I found. 112 LSA adv 4, 114 LSA adv 2, one that only says 111 LSA and 113.5 LSA adv 3 (called a blower cam). I didn't chart the blower cam or a straight up 111 LSA versions.

Note that Ronnie's cam card version, has the highest DCR of all the others.

Maybe KiWInUS could help us, in what versions he grinds.

[Bored&Stroked]

I've done quite a bit of CAM profiling - starting with graph paper, a degree wheel and a dial indicator when I was about 16 years old (long time ago). I was very interested in comparing Harley KR roller cams with flathead cams - and used my initial research to get Ed Isky to grind a couple flathead rollers for me (I made the billets out of 8620 AQBQ steel).

I graduated to better methods over the years and have owned the CAM Analyzer program for many years. Attached is a document I put together 6 years ago on some summary information on some of the cams I was looking at (that I own).

I'll also include a few graphs of a custom roller cam that I was using for one of my engines . . as compared to the Isky 404-A radius lifter cam. You'll see that while the 404-A has a faster initial ramp than the roller, ,then the roller "catches up" after about .100 lift. As Pete has said numerous times, what really makes the 404-A run are the fast opening ramps on it. Anyway, enjoy the material . . .

I'll have to see if I have a copy of the Isky 505-A profile information with me (am out of town), if I find it, will post it.

FlatheadCamshaftSummaryData.pdf

IskyRR630RollerVsIsky404ARadius2DegreesAdvanced.jpg

[Bored&Stroked]

It is important to note, that just knowing the lift, duration at .050, LSA, intake centerline and timing events are important, but there is a lot more going on in any particular design/profile to understand how one cam compares to another.

Unless you have a full graph of the profile(s), and understand a lot of the details it is difficult to compare them (other than at a really high level). Two cams with the same basic "numbers" can perform very differently . . . based on their profiles, ramps, lifter designs, jerk, etc..

Here is a little PDF from Dema that may help folks get into the details just a bit more . . .

http://www.engineprofessional.com/ar...Q215_62-66.pdf

Enjoy!

[outsider347]

Originally Posted by Bored&Stroked

It is important to note, that just knowing the lift, duration at .050, LSA, intake centerline and timing events are important, but there is a lot more going on in any particular design/profile to understand how one cam compares to another.

Unless you have a full graph of the profile(s), and understand a lot of the details it is difficult to compare them (other than at a really high level). Two cams with the same basic "numbers" can perform very differently . . . based on their profiles, ramps, lifter designs, jerk, etc..

Here is a little PDF from Dema that may help folks get into the details just a bit more . . .

http://www.engineprofessional.com/ar...Q215_62-66.pdf

Enjoy!

Tks

[38 coupe]

If you want more reading on camshafts these folks have a four article series you can read through: http://www.profblairandassociates.com/RET_Articles.html


Shortcuts to each article:
1 - The Right Lift
2 - Making the Cam
3 - Bucket Operation
4 - Pushrod Operation

[21stud]

Great thread, good reading! thanks!

[Ol' Ron]

very interesting article. Gona take awhile for me to read all this. Digesting it is another problem.
G

[JWL]

With the comments about Tunnel Rams I was inspired to uncover and photograph one of the manifolds I fabricated about 15 years ago. I did not use this in competition but a similar one was on the Bonneville car when we set some records. This one was a little better than the other but there is never enough time to do everything you dream about.

I have asked Coopman to help with picture posting to which he kindly agreed and I say a big THANK YOU!

[V8COOPMAN]

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Originally Posted by JWL

With the comments about Tunnel Rams I was inspired to uncover and photograph one of the manifolds I fabricated about 15 years ago. I did not use this in competition but a similar one was on the Bonneville car when we set some records. This one was a little better than the other but there is never enough time to do everything you dream about.

I have asked Coopman to help with picture posting to which he kindly agreed and I say a big THANK YOU!

This is the manifold that John (JWL) fabricated several years back. Talented dude, yes? DD