anybody ever build one? i would like to know if anyone has built one using a 394 block with a 4.25 stroke crank. any info would be greatly appreciated!
394's were stroked like me on prom night... all the time, and by EVERYONE.. search the rocket threads, there is some info in there, otherwise im sure donwow and the other olds gods will chime in
not sure about the combo you asked about, but i have heard that you can take a 403 and put a 455 crank in it (after having the main journals machined down) and end up with a 500+ cube engine....
haven't done it myself but talked to a couple different guys who had they both said with the 394 you want to limit the stroke to a half inch max, for skirt clearance, use the Buick 455 rods and of course custom pistons. hmm... .125 overbore, .500 stroke.... 475 cubic inches..
C-T Automotive sold 5/8s stroker arms ,,lots, used with .060+ bore =476 inches,,,,.125 overbore and the 5/8 arm gives 489 inches. Slight grinding to get 1/16 gap at bottom of bores to clear rods and use of 371 ,,57-58 rods gets you home with throws turned down to 371 size. And number 23 heads are by far the strongest---no beefing needed. Machine shop in midwest ---Terre Haute ---did one for me forty years back way cheaper than C-T price. This shop is still in the know and open. Yeah ,an arm in a 394 has some twist.
Could be,, Reath or any other from way back when this was popular, 9/16 stroke with 371 rod size was a standard build for a AA/SR along other combos.
Hi We do stroker early Olds kits and completes Do a search of my user name and see the speed parts we have to offer Tony Ross Racing Engines 1763 North Main St Niles,Ohio 44446 330-544-4466
do you guys offer high performance camshafts for the 394's? i tried calling your shop but nobody answered
One of the most famous cars using stroked 394 (alias GMC V8) was Hugh Tucker's "Ventura Motors" 1928 Chevy AA/SR with blown 476".
Ok old post but I want to bring it back up again. I was on you tube and saw a video of a guy in sweden with a g***er 55 buick with a blown 394, I messaged him to find out more about it. I said he put a 425 crank in the 394 block, I asked what machine work he had done. He said none he used the 425 bearings, and used 455 rods and pistons. That took him to about 8.5:1 compression. So I got to looking and the deck height on a 394 is 10.631 and the deck height on the 425 and 455 are 10.625 so I added up the 455 crank and rods and pistons comes out to 10.610. So has any one here tried the combo in a 394 yet?
My only Olds experience is with the DRCE only, but simple engine math and your formula comes up to pistons only .021" in the hole. A nice skim cut of .015" on the block deck to square and true, you pistons are now only .006" down. I would only deck .010"- .012", since you are using stock production rods and crankshaft, as this will allow for any varience in center to center length dimension, throws of the crank slightly off, and still keep the pistons below deck zero. BDM
Just what I was thinking bulldogmafia. I think it would work but wondered if anyone has tried it yet.
few things here, 394 uses rear thrust bearing 425 uses a center thrust 425 is a 2 year only crank and not at all common Block would need machined in rear and I seem to remember center main web is to narrow for 425 bearing and crank doesnt have any material to create a rear thrust Also its been quite some time since I checked all this and was trying to do it ,but I believe there was something different in the main bearing spacing and length of the shaft as well as timing gear alignment Ive done lots crafting in my time and anything can be done,but how nice is the end result? I can get you to around 440 ci with one of my strokers with a lot less h***le using more duable parts and not maxing the bores out Just my thoughts, Tony
No, you can't. Theres the fact that you cant take the mains down that far and end up with anything, same with the rod throws. You can, however, take a 425 (3.970 stroke) crank and cut its counterweights down enough to put in a 350 diesel block, and take the block up to 4.250 bore. Taking the rod journals down to BBC and evening up the stroke at 4.000....I have one under construction at the moment, and it comes up to a 454" olds. Smitty @ M&J in Louisville, Ohio is doing the short block.
Actually, the 65-67 400 and 425 Olds motors all used the same crank. It is forged and not really that hard to find even today.
Guys above here^^^^^ We are talking about earlier generation 394 Olds here Whole different animal what we call a late model Olds ....1965-80something Tony
Thank you Tony, I brought it back up to see what or if anyone body else tried anything new or what I was talking about. I wish the guy I found on youtube was a hamber. He is adamit that the set up I explained is what he is running with no extra machine work to the crank.
I think your talking about Thom in sweden Hes a customer of mine and a good guy I didnt sell him a crank so I cant verify what he did But I have had all the pieces in front of me and I know for sure its not a bolt together without work I also know he has had issuses with that engine ,and is building a new one with all the parts he bought from me Tony
I've got a 394 Olds motor and a 425 motor both of which I'm building for projects. I heard the cranks were interchangible so I tried the 425 crank in the 394 block and it does not fit the rear main area is definitly different. Pat
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