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.

Re: Stroker 21 stud
 

I haven't tried it with modern H beam rods. With 21A rods some grinding on the block was needed. No where near getting into water..The big problem was the extremely short skirt required on the pistons. It hurt ring life with .012/.014 clearance.

Re: Stroker 21 stud
 

They are very "SHARP"
I dont believe Al Sharp made any 21 stud heads .
Man I love them !!!!
It will be tough for me to decide which of my Sharp intakes to run with those heads , or my "Burns" intake would also look way cool !!!:D

Re: Stroker 21 stud
 

If I were having a crank welded I would start with a used crank. You are going to have to straighten and grind the journals afterwards anyway. Why do that to a new crank? What other crank are you going to find that will fit all those NOS standard bearings out there?

Allard, Tornado, and those weird waterless Federal Mogul heads are the only center water 21 stud aftermarket heads made back in the day that I know about.

edit: I meant Cyclone, not Tornado, wrong bad weather reference.

Re: Stroker 21 stud
 

Tony, they do look very nice!! Let me know if you hear anything on the actual cost for a pair of these for pump in heads.

Re: Stroker 21 stud
 

The Eddie Meyers go for 1100. Being that there is no other heads it might be comparable. Probably a deal if you want 21 finned aluminum heads.

Downloaded h&hs catalog off thier website for 2015. Man they are really keeping flatheads going. Much respect.

Re: Stroker 21 stud
 

In the late '50's, I had a set of Cyclone 21 stud center outlet finned heads. Try as I might, I couldn't make them work on my '36.

Re: Stroker 21 stud
 

i bet they looked alot like these heads ...wink wink ...;)
why would they not work ?

Re: Stroker 21 stud
 

If stock '36 engine and center outlet heads, there would be no place for water pumps ;) :)

Re: Stroker 21 stud
 

good point John , I was thinking 37 block .
Mike text me pics yesterday also , I will let you know when I get any price info.

Re: Stroker 21 stud
 

I wonder if the spark plug is still in the original location? Be nice if the people that take the trouble to make these heads, would take the time to up grade the combustion chamber.

Re: Stroker 21 stud
 

SCAT makes stroker cranks for the small journal 21's. Check out their part number 9-221-4000-2000.

Re: Stroker 21 stud
 

SCAT makes stroker cranks for the small journal 21's. Check out their part number 9-221-4000-2000.

Thanks for that most interesting information...hmmm...now you've got me thinking.
Has anyone on here got first hand experience with the above Scat crank?

Re: Stroker 21 stud
 

With that 4.750 crank did you run the real early style rods for cam clearance etc.? Must have been tight in there. I do like big motors though. :)

Re: Stroker 21 stud
 

That is interesting. I wonder what mains diameter you could get on these stroker crankshafts? It really didn't say in their on line catalog.

Re: Stroker 21 stud
 

21A rods.

Re: Stroker 21 stud
 

I called them a few months ago and they verified that part number had 2.399" main journals with a 4" arm. I did not ask if it had an oil slinger. At that time they had no stock and the price was high (don't remember exactly how much) but it may be possible to get one at a lesser price if it wasn't purchased direct from SCAT.

If a late merc crank was ground to 2.399" on the mains how would one address the oil slinger/ rear main seal. There is not enough diameter there to create the slinger. Boring the mains out to use the 2.499" bearings and using a 59A rear main cap with a seal seems possible but expensive.

Re: Stroker 21 stud
 

Slingers can be added simply by soldering

Re: Stroker 21 stud
 

In the 37/38 block, Reds headers mad an adapter to convert to the rope seal, Using several Ford parts, Pretty simple