Hi, I'm Leonard, (Spitfire02) and my current project is building a bracket car with an Opel GT (already tubbed & tubed) . I'm currently concentrating on building a high-rpm sbc for it! :welcome: Does anyone know of a source for spacers or thick bearings to put a small-journal crank into a medium-journal block?
08-25-2006 09:18 AM
Ask you question in the Engine forum and you will get more exposure.
moving it there.................It's my understanding that the 69 302 crank was a large journal crank.......................67-68 may have been different.....which is the same as a 283 crank.
08-25-2006 10:08 AM
TRW, or whatever they're called nowdays, makes/made spacers for this conversion. You might want to try them. I have the part# somewhere. If I can find it, I'll let you know.
08-25-2006 10:16 AM
[QUOTE=poncho62]moving it there.................It's my understanding that the 69 302 crank was a large journal crank.......................67-68 may have been different.....which is the same as a 283 crank.[/QUOTE
poncho62 hit the nail on the head, 69 302 crank is large journal. The 69 302 blocks were 4 bolt mains as well.
08-25-2006 10:29 AM
Why not just make a medium rpm bracket car? According to some, RPM equates to 'ruins peoples motors'.
67 was the only s/j 302. All my68 and later small blocks are large journal - 67 was the last 283, which was replaced in 68 by the 307. Even 68/69 327s (vette only) were l/j.
09-06-2006 08:39 AM
Small journal Chevys
Thanks for all the good info, guys. I found that to put a small journal (rare) crank into a medium journal block(With the 400 being the only large journal sbc) is expensive, whereas the spacers to put a 350 (med. journal) into a 400 block (ie 377) is reasonable. By small journal I refer to 2.30 mains and 2.00 rod journals, by medium, 2.45" mains and 2.10" rods, and for the 400 2.65" mains with 2.10" rod journals. Thanks Again for all the replies! :)
09-06-2006 05:52 PM
Small journal crang
Leonard, I would be a little nervous about using a small journaled crank in a high rpm motor JMO and if i did i would have it checked out by a good machine shop. Again,,JMO. Perry.
09-07-2006 02:03 AM
Yes by all means have it checked out by a GOOD crank shop, and have the whole reciprocating assembly balanced if your going to run some high numbers. BUT...there is absolutely nothing wrong with forged small jrnl. cranks. The highest HP (375) small block for years was the '65 327 F.I. Vette, and it was a small jrnl.
09-07-2006 04:44 AM
Do some research, I think it was Larry Torres who ran an Opel GT and Larry Kopp who ran a king pin Corvette. Either way they both ran small journal small blocks around 287 cu in and over 11,000 rpm in the 70's.
Small journal means less heat, less weight and more rpm. Yeah maybe the metalurgy wasn't as good then but maybe not, everybody wants a pre '64 Winchester because they are beter finished and SHOOT.