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Cal-look/High Performance => Pure racing => Topic started by: 69Stu on October 01, 2008, 12:54:51 pm



Title: Chevy or VW journals ?
Post by: 69Stu on October 01, 2008, 12:54:51 pm
I am starting to collect parts for a new engine, most likely 2332.

Are there any benefits in using Chevy sized journals over VW size ones?
Does it make the crank stronger, or weaker?

I am planning on using a raised roof case, so I don't think that clearance will be too much of an issue inside the case.

Opinions please.


Title: Re: Chevy or VW journals ?
Post by: Zach Gomulka on October 01, 2008, 16:58:21 pm
Larger jounals make the crank stronger because the main and rod journals share a larger cross section.


Title: Re: Chevy or VW journals ?
Post by: Airspeed on October 01, 2008, 17:39:25 pm

I am planning on using a raised roof case, so I don't think that clearance will be too much of an issue inside the case.

Opinions please.
With 84mm crank, the VW journals probably weaken the cam too much because you still to clearence the base circle of that.


Title: Re: Chevy or VW journals ?
Post by: Zach Gomulka on October 01, 2008, 17:47:01 pm

I am planning on using a raised roof case, so I don't think that clearance will be too much of an issue inside the case.

Opinions please.
With 84mm crank, the VW journals probably weaken the cam too much because you still to clearence the base circle of that.

True, but how often does a cam snap? Usually a busted cam is the result of a thrown rod. Not being a smartass, just asking ;)


Title: Re: Chevy or VW journals ?
Post by: 69Stu on October 01, 2008, 19:46:24 pm
I have allready got a pre-clearanced cam, am I likely to need to increase the clearance further if I use an VW rod journal?

And what about case clearance?


Title: Re: Chevy or VW journals ?
Post by: Paul Bate on October 01, 2008, 20:32:45 pm
Hello Stu,

I would recomend Chevy Journal it makes life a little easier go for a 5.500" rod and shoot for 60 thow rod to case clearence.

I hope this helps Kind regards Paul  :)


Title: Re: Chevy or VW journals ?
Post by: 69Stu on October 01, 2008, 21:48:19 pm
Thanks for the advice. :)


Title: Re: Chevy or VW journals ?
Post by: Bruce on October 02, 2008, 16:55:34 pm
If your H-beam rods have 3/8" bolts, it is unlikely you will be able to make a VW journal crank fit.  5/16" bolt rods can work.


Title: Re: Chevy or VW journals ?
Post by: 69Stu on October 02, 2008, 17:07:06 pm
I was planning on using 3/8" bolts, so it looks like Chevy journals are my best option.

So to another question. At what point would you recomend going up to a Type 4 Centre main bearing?


Title: Re: Chevy or VW journals ?
Post by: Mike Lawless on October 02, 2008, 17:38:04 pm
Shouldn't need the type 4 center main until or unless you will be consistently above 7500 rpm or over 225 hp. At that point, you might as well go with all type 4 mains.

I don't think anyone offers a type 4 center main crank anymore do they? I know Bugpack's new stuff is all type one, and their new flanged crank is all type 4 (used to be type 4 center), and CB's have always been all type 1.

To have one welded to type 4 just doesn't make any sense in my mind.


Title: Re: Chevy or VW journals ?
Post by: 69Stu on October 03, 2008, 14:03:10 pm
Scat's web site does actualy list their pro comp cranks as being available with a type 4 centre main.

But, this is for a street engine with occasional strip use, so I won't be turning 7500rpm that often, or producing that much power.

Thanks


Title: Re: Chevy or VW journals ?
Post by: louisb on October 03, 2008, 14:33:05 pm
DPR can do a welded crank with Type 4 center main.

--louis


Title: Re: Chevy or VW journals ?
Post by: NoBars on October 03, 2008, 22:45:30 pm
Yeah, DPR just built me an all type 4 86 mm


Title: Re: Chevy or VW journals ?
Post by: John Rayburn on October 04, 2008, 09:14:08 am
My 84 / VW journal crank and H beam 5.5 rods take the same space as my old 78.4 stock rod combo. VW journal is much stronger and clearance on the cam is no problem for longevity.


Title: Re: Chevy or VW journals ?
Post by: nicolas on October 04, 2008, 22:07:33 pm
My 84 / VW journal crank and H beam 5.5 rods take the same space as my old 78.4 stock rod combo. VW journal is much stronger and clearance on the cam is no problem for longevity.

i am taking notes here.

what rods do you use now?


Title: Re: Chevy or VW journals ?
Post by: John Rayburn on October 05, 2008, 08:12:06 am
They're 5.5 Eagle's.


Title: Re: Chevy or VW journals ?
Post by: 69Stu on October 05, 2008, 15:57:52 pm
So how would the clearance of Eagle rod compaire with other brands of rod?


Title: Re: Chevy or VW journals ?
Post by: Bruce on October 05, 2008, 21:15:05 pm
So how would the clearance of Eagle rod compaire with other brands of rod?
Depends on the bolts in the rods.  John's Eagle rods have 5/16" bolts.  Try to fit Scat rods with 3/8" bolts, not gonna fit.