Stroker 21 stud
 

Guys looking for input here ! I have a 37 core engine .
I was talking to a very good friend on mine last Friday (well known flathead builder from LA) about building a 21 stud to put his NEW Sharp heads on (I have a very large collection of Sharp speed equipment) & he suggested I put a 4in Merc crank in it . Well after some thought , I would have to grind Merc crank mains to 37 size , cut the counter weights down plus grind rod journals down to 2" , use a set of NOS 21A rods so all of that comes with a nice bill from my crank guy .
So here's what I think I may do , take a 37 crank (I even have a NOS one) have my crank guy weld the rod journals & make it a 4" crank , he confirmed today that he can do that for me no sweat .
I would bore it to 3 3/16 & of course it would get the "Famous" KiWi-L100 cam!!!
Th 37 crank I believe would be way lighter I believe (Brian from NZ will like that !)
So what do you think guys ????
Cheers
Tony

Re: Stroker 21 stud
 

I'd say talk to Walt... Maybe talk to a 'higher authority' to get that bore. :)

Re: Stroker 21 stud
 

Tony, don't you mean bore to 3-3/16" :)

Re: Stroker 21 stud
 

That JM don't miss a lick,he always correcting me too.

Re: Stroker 21 stud
 

Don't you have to do a offset bore on early blocks and 4+ cranks...

Re: Stroker 21 stud
 

Giggle.

Re: Stroker 21 stud
 

Just imagine if we could bore a '37 block to 4-3/16"

4.1875" x 4.1875" x 4" stroke x 8 cylinders x 0.7854 = ~ 441 cubic inches

We might tear up some transmissions and break a few axels with that one :)

Re: Stroker 21 stud
 

Several years ago, I cut down an 8BA to 2.398, had to increase the width of the front and center maind aprox.'050" Bored the block to 3 3/16, installed an L-100 cam.
This engine went into Paul Howard's (AV9 Paul)roadster and is still there.
This was a prelude to installing a 4" crank I used 8 BA rods and the engine spun a bering after 20k plus miles. Thank goodness Walt fixed it.
The engine ran very well and was clocked by the Arazona SP at 105 MPH, so I was told. Yes it would be expensive, but I just wanted to prove a point and it worked.

Re: Stroker 21 stud
 

Just a thought, why not line bore too 2.498" and use the 81A bearings? If I did it, I'd bore it 3 3/16" and use 8BA rods and bearings. Sure this would be a chunk more cost effective. Yes the 21 stud crank is lighter, would you be able to feel the difference? I doubt it. With a welded and stroked 21 stud crank, you wallet would be considerably lighter!
Now about these Sharp 21 stud heads?
Martin.

Re: Stroker 21 stud
 

H&H Flatheads is bringing the 21 sudders back to life. They have posted pictures of them on Facebook.....beautiful!!

Re: Stroker 21 stud
 

Are they centre outlets 37- early 38 type? Have they got a price? I don't do face book.
Martin.

Re: Stroker 21 stud
 

They are water pump in head 32-36 style .
Sorry guys typo on the bore size = wishful thinking !
My crank guy can fix me this crank for a very reasonable cost . It would cost me more to rework a Merc crank.
I just have to decide whether to pull crank from my core engine & give him or have him use the NOS crank I have .:D

Re: Stroker 21 stud
 

They are doing both scooder. I downloaded pictures posted by H&H on Facebook to post here. Patterns, castings, and finish machining. No idea on price, but guessing about the same ball park as Don Orosco charges for his reproduction Eddie Meyer 21 stud heads.

Re: Stroker 21 stud
 

Thanks for that John, they do look sharp! If they got those patterns maybe they got the four carb manifold pattern too. That would be brilliant. I want me a Sharp four two.
Martin.

Re: Stroker 21 stud
 

He can weld up and regains too four inch cheaper than grinding up a Merc crank? I wouldn't have expected that! Makes me start thinkin about four and a half inch strokers!
Martin.

Re: Stroker 21 stud
 

4.5" welded cranks were quite common in the old days among the top drag racers. It was all that was available for practical purposes.
Depending on how much nitro was applied, they usually lasted about 10 to 15 runs.
I welded several for circle track engines running on gas and they never had any problems with them. I even made a 4.75 stroker once.
We welded diesel truck cranks every day and never had any problems with them.

Re: Stroker 21 stud
 

Funrunr, I actully meant 3-3/16". Thanks for catching my mistake while trying to correct someone else's mistake. LOL :D

Re: Stroker 21 stud
 

4.75! Damn!
Martin.

Re: Stroker 21 stud
 

Pete I would think a lot of clearance in the block would be needed for the 4.750 stroke ending up opening into the water passage was the block filled solid?
Ron

Re: Stroker 21 stud
 

I hope Brian chimes in on this thread. He is a demon with the early engines.