What are the preferred rod lenghts?

NCTURBOS

Gettin' back in action!!
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Joined
May 26, 2001
I was wondering what the preferred rod lenghts are for the below cranks.

3.400 = ? rod ?
3.590 = ? rod ?
3.625 = ? rod ?

I'm wanting to start shopping and I need to know what direction to head. Thanks for any input!!
 
ROD LENGTH

6.25 Works well for the stroker cranks(3.59 -3.625) , gives room for the piston dish ,the thickness of the piston top (needs to be thicker on turbo piston.)and the top of the pin . It gets very tight with the stroker cranks and 6.5 rods,and to try to keep the comp. ratio down in the 8.5 to 1 area. 6.25" length rod with a 3.59 crank is very close to the factory rod to stroke ratio.
 
Bill,

With a 3.625 stroke and a 6.5" rod will the ring package (the oil ring) move into the pin area of the piston? Im also talking about a JE dish turbo type piston. Also will the piston be strong enough for this stroke/rod length?
 
Yes it will be into the oil ring land, this does not cause a problem. Pistons will be plenty strong enough, this will usually make the top of the piston, just above the rod .180-.200 thick at the thinnest part.
 
Bill,

Another question for you. If I were to use a 6.50 rod and a 3.590 stroke instead of the 3.625, would extra .030 be enough to use the thicker ring package as opposed to the 1/16" ring package? Thanks.
 
Really? You dont subtract 3.590 from 3.625? Cause that gives .035 less stroke no? I wanted to use a the thicker ring package for better durability. I have that now on a 3.625 and 6.200 rod. Thanks again Bill.
 
Originally posted by lazaris
Really? You dont subtract 3.590 from 3.625? Cause that gives .035 less stroke no? I wanted to use a the thicker ring package for better durability. I have that now on a 3.625 and 6.200 rod. Thanks again Bill.

.035 less total stroke, but only .0175 at the TOP of the stroke, which would affect what you can get away with on compression height. FYI, I've got a 3.590 / 6.5 combo, with Diamond Racing pistons that use a 1.5 mm top and second ring setup, and the pin is below the oil ring. If it'll make you fell better, the new 3800 SC motor uses a really thin and low-tension ring package, and we know that Buick wouldn't put out something that would fall apart too soon. (Don't we?)

It'll work, like Bill says.:)
 
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