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Cal-look/High Performance => Pure racing => Topic started by: airstuff on December 03, 2008, 17:17:42 pm



Title: Rod ration and lenght
Post by: airstuff on December 03, 2008, 17:17:42 pm
Hello guys,

Can somebody explain thoroughly what is the advantage of running 5.500 rod on the 2276cc engine,versus 5.394 rod,if there is any marginal  difference ::)

Is it easy to assemble.

I assume engine will be much wider with 5.5 rods.


Title: Re: Rod ration and lenght
Post by: Peter on December 03, 2008, 18:34:07 pm
i used 5.5 rods
my engine is only a few mms wider than stock


Title: Re: Rod ration and lenght
Post by: Ohio Tom (DdK) on December 05, 2008, 03:13:22 am
5.500" rods are just plain easier to setup than 5.400" (5.397").
VW length rods with an 82 stroke crank is ceartainly do-able, but you will  have to check the case-to-piston skirt clearance.
Also, the Piston skirt-to-crank shaft will also have to be checked.
You should do these checks in any case, but you will almost certainly have to do some extra clearancing with 5.400" rods.

Plus, I prefer to have longer rods that keep the piston "inside" the cyl at BDC. This reduces "piston scuffing" issues..
 .100" doesn't sound like alot, but every little bit helps...


Title: Re: Rod ration and lenght
Post by: Mohawk on December 08, 2008, 21:20:20 pm
What's the difference between VW rod journal - 5.500" and Chevy rod journal - 5.500"?
If I use 5.500" length on the rods must I use steel barrel spacers? I will run a crank with 82mm stroke and 94mm cylinders. I don't know if I should use normal pistons from Mahle or more expensive one from Wiseco?


Title: Re: Rod ration and lenght
Post by: Zach Gomulka on December 08, 2008, 21:56:00 pm
What's the difference between VW rod journal - 5.500" and Chevy rod journal - 5.500"?

The diameter of the big end of the rod. Smaller diameter gives more room inside the case, but also makes for a weaker crankshaft.

If I use 5.500" length on the rods must I use steel barrel spacers? I will run a crank with 82mm stroke and 94mm cylinders. I don't know if I should use normal pistons from Mahle or more expensive one from Wiseco?


You wont know until you trial assemble the engine. Mahle vs Wiseco... depends on what you are building the engine for I suppose.


Title: Re: Rod ration and lenght
Post by: Mohawk on December 08, 2008, 22:12:56 pm
What's the difference between VW rod journal - 5.500" and Chevy rod journal - 5.500"?

The diameter of the big end of the rod. Smaller diameter gives more room inside the case, but also makes for a weaker crankshaft.


If I use 5.500" length on the rods must I use steel barrel spacers? I will run a crank with 82mm stroke and 94mm cylinders. I don't know if I should use normal pistons from Mahle or more expensive one from Wiseco?


You wont know until you trial assemble the engine. Mahle vs Wiseco... depends on what you are building the engine for I suppose.

Is the Chevy rod journal - 5.500" stronger?
Drive fast I guess but at the same time a engine that I can drive long tripps with without problem  :)


Title: Re: Rod ration and lenght
Post by: Lids on December 08, 2008, 22:23:48 pm
what are peoples thoughts on a 5700 rod, I umed and arghed for ages, I still think this might make better power than a 5500


Title: Re: Rod ration and lenght
Post by: Zach Gomulka on December 08, 2008, 22:42:33 pm
What's the difference between VW rod journal - 5.500" and Chevy rod journal - 5.500"?

The diameter of the big end of the rod. Smaller diameter gives more room inside the case, but also makes for a weaker crankshaft.


If I use 5.500" length on the rods must I use steel barrel spacers? I will run a crank with 82mm stroke and 94mm cylinders. I don't know if I should use normal pistons from Mahle or more expensive one from Wiseco?


You wont know until you trial assemble the engine. Mahle vs Wiseco... depends on what you are building the engine for I suppose.

Is the Chevy rod journal - 5.500" stronger?
Drive fast I guess but at the same time a engine that I can drive long tripps with without problem  :)

The smaller the rod journal, the weaker the crank becomes. The shorter the rod, the stronger it is.
Standard issue Mahle's will work great for your application.


Title: Re: Rod ration and lenght
Post by: airstuff on December 14, 2008, 13:46:34 pm
i decided to torture myself clearencing 5.4 I-beams with the 82 crank :D


Title: Re: Rod ration and lenght
Post by: Fasterbrit on December 14, 2008, 19:45:25 pm
what are peoples thoughts on a 5700 rod, I umed and arghed for ages, I still think this might make better power than a 5500

Peter from CSP runs a 5.7 inch rod on his 78 x 94 turbocharged CSP Ghia. He swears by this ratio for upper end power and revs. It makes 500 hp at 9,200 rpm on the JPM dyno! One hell of a wide motor for a stock bodied car though! :o


Title: Re: Rod ration and lenght
Post by: Lids on December 15, 2008, 21:20:35 pm
thanks for the reply Mat, Jim @ stateside talked me out of it, said it would really need a flanged crank as well, or he wouldn't guarantee it.  If I have a good new year I might change my mind.  84 flanged crank, 94 forged pistons, long barrels and a 5700 rod :)  Should be fun  8)