olds48

I don't know this for a fact,but have been "told" on more than one occassion that a point of compression is worth roughly 3-5% :? ?????

hammertime

Making another change also was going to just recondition rods but decided to buy new instead while doing so I am changing from 6.385 to 6.535 for a better rod angle. Machine shop thinks this will take advantage of the heads I have. what do you guys think about this swap ? :shock:

zipper06

The longer rod in most cases will help because it reduces side load on the piston and permotes better sealing of the rings due to piston rock. Ofcourse the higher up you get in the piston with the rod the less rock anyway. I think there's also a theory that the piston travels faster on the down stroke with a longer rod, but i don't know how that works. If you look at the Nascar guys, they are running real short pistons, 3.2 stroke and 6.2 lg rods with the sm/blk chevies and i don't think they base that on theory, but instead what works best, produces power, and what runs longest without losing power from piston and ring wear.
How much HP gain? i don't know :wink: only the the car will know.

JMO

Zip.

hammertime

Zip thanks for the reply, I was thinking the less piston rock also main reason I actually decided to go this way, plus if there is a chance ya gain a few horse might as well try it for the same money

I am trying a new rod this go around, always iffy on doing this, I am a big eagle fan with the L-19's, was going to go callies compstars or K1's decided to go K1's with arp 2000 bolts, motor shop has used them a lot in some high HP stuff with nitrous and says they are a great rod, better then eagle and equal to callies compstars for sure. I also elected to go with Diamond Pistons 14:1 compression.

hammertime

Hope to find out the difference here in the next 2-3 weeks, got it started up today for first time. Good to hear a race car again

BEAST477

Yeah hammertime nothing like the sound of big cubes and the smell of race fuel. I'll bet you were glad to hear it fire again.

dparker

David, are you running racing fuel or alcohol on this engine.

hammertime

More then glad to hear the sound of a race car besides on tv and the www lol

hammertime

This will be a alky motor with a terminator on it .

ashbros

I had a 615 BBC on alky that was at 13.5/1 made 974 hp kicked it up to 15/1 made 1084 hp didn't change anything else on motor