Scat 221 stroker cranks

[Yoyodyne]

Originally Posted by Talkwrench

Well at least you're moving along Brian. Im still screwed and cant find a decent 37 crank around here that hasn't had more than .022 of the mains already .. Really need a set of .040 flanged floaters to move on ..oh yes and there is the problem as you know of my machinist than cant find my bearing caps ..pfft!

I have 2 pairs of .040 flanged bearings if that will help you, I've been too slack to list them for sale, and haven't found any more to make a full set.

[A bones]

Originally Posted by rotorwrench

The Tex Smith flathead book had an article about a 37 engine that was modified for the Great American Race (GAR). They used a late 255 Merc crank with a lot of mods to work in a 1935 coupe. They wanted 3 3/16 standard 255 pistons and 4-inch stroke all in a little 221. They bored through the cylinder walls to get larger sleeves to fit. I know they turned the crank and it seems like that had to clearance somewhere else to get the 4-inch assembly to work but I'm not sure where. These things become apparent after you get a rotating assembly in there and start turning it though. It wouldn't take long to find any other clearance problems at that point.

Gotta love that era! Guys could just grind, cut, slice, and dice. If it didn't work out (blew up) they'd simply go back to the 'well' (pile) grab some more engines and have a re-do.

[Brian]

Well...there has been several emails back and forth between myself and Scat. Their last correspondence reads;
Hello Brian,
I talked to our engineers and he says we know our crank will fit in late 221 blocks. There are a few variations of the 221 and some will require extra machine work. We have a 33 and a 34 in the shop and will be seeing if it fits into that block too


My reply:

Hi Alex, There are three basic versions of the 221 block, with corresponding three different crankshafts;

The 1932-mid 1936 versions run 2" diameter main bearings.

Mid 36- 1938 the main bearing diameter was increased to 2.4"- this is the version of the crankshaft you are fobbing off as fitting, when indeed, I assure you, it does not!

1939 and later 221's had increased main bearing dias again of 2.5", BUT with the reduced lengths of front and centre main journals as you've made!

Has your 'engineer' got a contact number please? I'd like him to explain exactly which series engine this crankshaft purportedly fits.

Realise please, I am in New Zealand, I am NOT making any form of warranty claim, the logistics and time delay in sending this back to you make that impossible! I have to 'fix' the problem; I am simply drawing to your attention that you guys have made this this incorrectly, in order you may rectify the problem in subsequent production. As it is, this particular crank will not fit into any 221 block-well it would fit into a post 39 block, but the journals would be 0.100" undersize!

There you have it! I'm being nice! Should you guys continue to bury your heads in the sand and refuse to see there is a problem, then that tells me much about your organisation.

I've just tried ringing you, operator informed me you were out to lunch. Wouldn't put me through to engineering dept. I've fixed the crankshaft my end, you guys need to sort out this simple engineering operation your end.

Regards, Brian

So....my original heads up to anyone contemplating purchase of one of these cranks stands; they will not fit without subsequent machining operations.

[rotorwrench]

They shouldn't have misrepresented the crankshaft for what it is not. My guess is that they didn't do enough research to find out the dimensions for the late 21 stud version of the 221. Grinding the journals smaller was only part of the work that was required. You would think that they would find an original late 21 stud crank to spec it out properly.

I think they either need to tell perspective buyers that it needs the cheeks & journals machined out or do the diligence to get them to where they need to be. Too many folks overlook the details when they offer up specialized parts like this. Cutting the cheeks wouldn't be too bad an operation but the journals need the correct radius in them too.

[Talkwrench]

mmm reminds me of the time I emailed MT [Bolling ] regarding the workmanship and part they welded wrong and scored a drum. Sent me back a reply that said "we have had a few plates move during welding" . And that's it, nothing more ..? Makes you wonder..

[quarterinchbore]

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Buy Asian garbage;support their economy;help them copy and overrun everything our forefathers sweated and slaved to produce and perfect. Henry would roll over in his grave!

[rotorwrench]

Not to worry. Word gets around pretty well now days just like this thread. If folks make crap (no matter where it's made) then their sales will be lower and lower as more folks find this out.

[KiWinUS]

Originally Posted by quarterinchbore

Buy Asian garbage;support their economy;help them copy and overrun everything our forefathers sweated and slaved to produce and perfect. Henry would roll over in his grave!

So all that being said
What is your solution for a brand new 21 stud 4” crank? That some of us want but don’t own a bank?

[Lawrie]

What would be involved in using a 2.139 journal 239 crank,offset ground to 2.00 and 4in stroke, machining wise to make it fit into the early block.
Surely some one has looked at this.
Lawrie

[Bored&Stroked]

Originally Posted by Lawrie

What would be involved in using a 2.139 journal 239 crank,offset ground to 2.00 and 4in stroke, machining wise to make it fit into the early block.
Surely some one has looked at this.
Lawrie

You can't offset grind that to a 4.00" stroke - only 3 7/8" stroke . . . which is a real odd-ball as far as pistons go. You'd probably have to have custom compression height pistons made - to get the pin in the right location.

If I was going to get into all of this, I'd probably 'hack up' a 4" Merc crank - but that will get expensive in short order. After all the screwing around, it might actually be easier to have a billet crank made - though that ends up being a $3000 bill and lots of lead time to get it done.

Stroke wise, would be fun to get to about a 4 1/8" stroke 221 - with a light-weight and correctly designed billet steel crank - that would be fun!

[Lawrie]

OK my maths was out the window.
Maybe you are right.a custom crank.$$$
Lawrie