8BA stroker kit
 

Machine shop called me this am to tell me the 4” crank I brought them was cracked on a main journal. Time for a stroker kit.

This is a stock engine, stock carb/ignition. How big of a stroke can I go with? I want to go with at least 4 1/8 stroke but would to go 4.25 if possible, thoughts?

JB

Re: 8BA stroker kit
 

4” crank on the way. I just didn’t like having to bore this good block out to 3 5/16 for the 4 1/8 and 4 1/4 stroke. 4” is plenty

JB

Re: 8BA stroker kit
 

Good choice. Did you order a brand new 4" crank?

Re: 8BA stroker kit
 

I did.

JB

Re: 8BA stroker kit
 

Just an FYI. you don’t need to bore block just because you install a 4 1/8” or 4 1/4” crankshaft. Either would have been a great addition and additional c.i.

Re: 8BA stroker kit
 

I was wondering the same. I think because the stroker kits usually come with pistons, rods, etc. as part of the "kit".

Re: 8BA stroker kit
 

If anyone knows of affordable (same price or very close to 4" stroke) cast pistons for +0.060 or smaller overbore and a 4 1/8" stroke please let me know.
All the available 4 1/8" and 4 1/4" stroke pistons I find these days are +0.125 or larger over bore and many are forged. Unless building a hot rod engine these don't make sense to me. Given piston availability the 4" stroke crank makes sense to me.

Re: 8BA stroker kit
 

38 Coupe,

Have you called Egge? I'm pretty sure they'll do any size. Ross will as well, but I'd assume they would be out of your budget range judging by what you said in your post.

Re: 8BA stroker kit
 

When I talked to H&H yesterday it seemed like a 4.125 stoke was not in the cards without a 5/16 bore. But I see a 4.125 scat with standard size rod journals and Ross makes a 4.125 stroke 60 over piston so not sure why that combo will not work with standard rods. I am going to call H&H this morning and dig around a little more.

JB

Re: 8BA stroker kit
 

This went from being a stock build to a stroker motor real quick and I love it! LOL!

Re: 8BA stroker kit
 

I would not build an 8BA without a 3 5/16 bore. I have done 3 of them and the machinist said they all would have gone more. ("OL' Ron" has mentioned 3 7/16"+ engines). To be fair, I did have to have one cylinder sleeved because of a casting flaw that caused a pit in the wall. The machinist said we could run it as is, but a sleeve would be good insurance.

The pistons cost about the same and like they say, "There is no replacement for displacement".

Re: 8BA stroker kit
 

Exactly!

Re: 8BA stroker kit
 

Yes - I would bore to 3 5/16 as well and if you're ordering a kit (depending on the rods you'll be using), I'd go to 4.125 or 4.250 stroke. There is nothing like the additional torque and cubic inches to bring a broader smile to your face! LOL

Here is the kit I'd order:

https://www.scatcrankshafts.com/product/1-94617bi/

Re: 8BA stroker kit
 

These are not modern castings that are "done" at .060" over. Henry made 'em to last.

Re: 8BA stroker kit
 

The problem with the 4.125 crank is the lead time on 4.125 60 over pistons. Well over 4 weeks to have them built. 4” 60 over are much more readily available.

JB

Re: 8BA stroker kit
 

Gosh, I remember when I bought a complete 296 stroker kit with floating rod bearings and Jahn's pistons from Crankshaft Co. in CA in 1967 for about $500. Then it cost me a whopping $5 per hole to have it bored. My pay back then was $1.15 per hour. Took a lot of "saving up".

Re: 8BA stroker kit
 

3twinridges , I sent you a email or pm , I forgot what I clicked on . Its about a motor I have that I’ll not be needing now . It sounds exactly like the one you want to build .
Gary

Re: 8BA stroker kit
 

I am going stay with the 4”. Machine shop talked me out of a 4 1/8. They were afraid the extra stroke would put strain on the bearing caps and introduce more wear than a 4” for not much gain.

Re: 8BA stroker kit
 

Appreciate it but the purpose of the build is to introduce the kids to an iconic engine build. I want them to see one get put together and help me. Again appreciate the offer. Follow along as we have fun with it!

JB

Re: 8BA stroker kit
 

For what you are looking to do, makes sense.

While you are in there, may I suggest cleaning up the exhaust and intake ports?

You can do this with sand paper rolls and a long arbor. The little effort/time it would take, it would make a difference and it will sound a little more like a hot rod flathead if you can get it to breathe better in & out.

Re: 8BA stroker kit
 

I would get a new machine shop if he truly said this. He clearly has limited flathead knowledge. JMO. Good luck.

Re: 8BA stroker kit
 

The spare engine for my Roadster is a 3 7/16 by 4 1/8 stroke, with a Potvin 400 cam. This engine was built in the late 50's, in LA by Joe Reath.

Re: 8BA stroker kit
 

Out of curiousity, how many cubes would that be? And none of those 'overseas parts' ! Has it been run?

Re: 8BA stroker kit
 

This is just me thinking.
Been in engines since mid 80’s, but not FH, but racing in NHRA stock with Hemis 9.70’s and 3.700 LBS, but sold China stroker kits for some years until low pricing cruched market ( that was over 15 years ago and quit as I did not like the smell of the Chinese oil and help their business ) and I has grind cranks, balance crank and linebore is my daily work, sell line bore fixtures world wide( BlockLiner ) and I’m European dealer of Turner balancers and sold near 200 of them since 2002.
Started in a WInona and a Berco 1985 cutting steel.

-I dont like Taiwan parts or steel in a old Henry.
A crank Merc crank from the swap remove plugs, hot tank it, check on cracks, grind it.
Use the std rods and if cylinders was Ok just leave rhem up ruff upp clean and get Ross pistons and 1.5 mm rings.
Shore pistons might cost but crank/rods is not that pricy plus good ol’ Henry.

I know a guy had a 8BA and std bore and 4” crank and std rods and idea was thickest possible wall and not press in cylinders more than needed.
Ok this was racing, you has a street motor.
I actually has one of his old rods here.
He was RPM it and went 156 MPH at 7K foot 20 years ago in a big Merc.
For me that say something and hat off and cool factor big.

But again, just my ideas.
I has a Eagle CSB up in balancer now and it sad to see we need to has Chinese make it for us.
Sweden us famous on steel and forgings.
Ex where I live ( mid Sweden ) they brought up the metal Henry used for bearings ( SKF ) but now in north Sweden idea is ’green steel’ and it cost all here a fortune in taxes and its a big disastre ( green people in charge ) as no one will pay more for green steel, and Chinese will not invest in green steel…
So the Chinese or Taiwan made steel is not just my cup of tea.
But dont take my word on it.

Re: 8BA stroker kit
 

GB, i think its 306, the engine was originally in a 40 ford coupe that was a show car. i got the engine from the nephew of the owner, who passed away many years ago.

Re: 8BA stroker kit
 

306 is correct. :)

Re: 8BA stroker kit
 

Just wondering................ does increasing the bore (decreasing the thickness of the cylinder walls) especially to 3 7/16", affect the ability of the block to dissipate heat resulting in higher operating temp?

Re: 8BA stroker kit
 

Jim,

If I may jump in and share my experience. My motor is 3 3/8" +.030. Not quite 3 7/16", but close. I am able to run without a fan 90% of the time. Only in stop and go traffic in high temp/high humidity does it get close to 230+ and on the 2nd day of TROG racing did I need to put it back on.

Most of the time, it barely gets to 180 degrees.

I was methodical about cleaning the block and sonic testing indicated I had a decent amount of wall left even going that big. (I'll need to look at my notes to say exactly how thick).

I also run water with 180 degree thermostats, Skip's pumps and a Walker radiator.

Re: 8BA stroker kit
 

I don't think a stroker kit is a practical move for a street engine. The cost is not justiable, considering the application. also most stroker kits have the wrong pistons. Just get another 4" crank and use a stock style 4 ing piston. also the use of milled EAB heads and cam will bring the CR near 8:1 all this is reasonable in cost and reliability . Properly tuned good fuel mileage and Lots of low end torque.
Gramps

Re: 8BA stroker kit
 

To follow up on what "Ol' Ron" posted, it's perfectly alright and actually beneficial to leave the fourth (bottom) ring off of the pistons if you have the rotating assembly balanced. I did on my last build an everything is fine. SWord has it that some engineers Ford borrowed from Studebaker (or was it GM) added it to solve an oil consumption problem. Modern ring technology has that whipped, so the fourth ring is superfluous.

Re: 8BA stroker kit
 

I has a cool old book, 'How to hop up Ford & Mercury V8 engines'.
1951 edition by Roger Huntington.
I like it as it describe the era.
It's allot of dollar to dollar vs overbore vs stroke and in page 45 they mean the best way is to get a new 4" Merc crank and not stroke a 3.75" but they don't recommend to stroke the 4” vs the dollar to dollar and the 3% it get back.
-One must love the reading !
So they figure out the stroke get not much return but bore get decent back, vs dollar to dollar.

But if one has a good old block std I would never would bore it to boost HP or fit a 'stroker crank pistons', I should hone it fresh and order pistons and modern rings for hole.

The Bonneville car I talked about could had more cubics ( in class but stayed at 4” and std bore vs keep the wall thickness and he used 1 mm rings and fat cam.
At that time Total Seal had not rings ( as today so it came from a US made 4-cyl car and cam was made in home.
-I’m super impressed on that engine/tech 25 years ago, and wanted to mention of the ideas on bore/stroke and the use of Henry parts that worked just fine up at 7.000 RPM.
US made block as rules say, ported runners std design and 1 carb and headers ( and no blower )
Shore I’m certain the low end TQ was not much, vs low compression and cam ;- )

Re: 8BA stroker kit
 

The only thing that makes horse power in any engine is air, it lets the fuel burn to make the power. getting air into a flathead is why it's hard to make HP. Ask the other Ron he makes alot of HP and he uses a blower, and he knows how to hold the whole darnthing together.
Gramps

Re: 8BA stroker kit
 

I like se Ronsroadster get to 200 MPH less a blower !
But 157 MP in a Merc 49 20 years ago is d-n fast.

Re: 8BA stroker kit
 

I really love these old stories, but the veracity of the timing devices is always in question. Do you have any detail on the timing system that was used and how it was verified?

When I was into vintage racing years ago, we had a saying : "The older I get, the faster I was."

Re: 8BA stroker kit
 

People read this and are into it, know what I talk about.
Timing system was SCTA.
-I’ll just mean ( thread topics ) a Ford is all fine to has a Henry crank/rods and this a very nice example from what 4” and std bore can do with OEM parts.
Matter of fact, its maybe 30 years ago, maybe even more.
I dont mean of racing, my idea is/was much more soul than put in Taiwan stuff.

Re: 8BA stroker kit
 

Like any project, Its all a matter of how much money you can afford to play with, If your on a budget, do what ol Ron said, if you have some money to blow, do a stroker!! They are not a cheap motor to make horse power with for sure but dang it i love the sound of my stroker motor!! LOL Its all good. In any case, I would bore it at least 5/16--- 3/8 is even better as was said once in awhile you have to sleeve a cylinder but that's not the end of the world. If you do bore it and make a stroker , make sure you do a good job of cleaning the block, they have a lot of core sand in them and cleaning them really good makes them a lot easier to keep cool. A nice heavy duty radiator is also a good investment as well. have fun!!

Re: 8BA stroker kit
 

The main reason I "only" bore to 3 5/16 is that this leaves you about 2 more over bores in the future. If you have a good block (especially if it has extensive port/relief and valve work done to it), you sure won't want to have to pitch it when the bores are worn out. Now, this may not happen in your lifetime, but it can sure happen to the "next guy".

Unless you're all-out racing, the few additional cubic inches are really not necessary - so why bore to the typical 3 3/8 max bore diameter?

Re: 8BA stroker kit
 

If I had a good std block I would never bore it.
In my 'new' Merc 41 block that is ported way back and are 1/8 over I was into for 'time line or era before 49' as the resons to has a baby stroked 3.75" crank and then as block is told be 'thick' I did math on bore it max or sleeve it as it get more pay on cubics.
But this block might be vasted as it has a weld repair and one cylinder has a porthole so its not a good decent std block. That's why I will play with it.
But now as I bought a baby stroked 4" crank I leave it at 1/8 over.
But it must be honed so custom piston is needed.
But my main idea ( this is personal ) I like to use the Henry stuff.

-Bore&Stroked, do you know the Merc story ?

Re: 8BA stroker kit
 

Unless you're all-out racing, the few additional cubic inches are really not necessary - so why bore to the typical 3 3/8 max bore diameter?[/QUOTE]


You only live once, so why not? Have fun while you can. Still a bunch of blocks left if, for some reason, you can't clean up the 3 3/8ths one more time.

Re: 8BA stroker kit
 

To each his own Tim! When you have 150 hours into port, relief and lifter bore work and a lot of time/money on fitting things like steel main caps and a bunch more money on oversize valve seats, custom guides, big valves, etc. . . . it is nice to know that it will have some "life" left in it.

I do have a race block at 3 5/16 + .030 . . . just glad I have "more bore to play with"!