6-Pack vs. LY rods

Postby pscartozzi » 21 Apr 2004 4:08

I am planning my engine build and I had a rod question. I just bought a det of 6-Pack rods on ebay for $50. I couldn't pass for that price. Now that I think about it, I was wondering if it really makes sense to use them. My intention is to build a 400-450 hp street engine. I know the 6-pack rods are stronger but they are heavier. Am I better off using the lighter LY rods? I hear they are plenty strong.
Perry
pscartozzi
 

Postby dave-r » 21 Apr 2004 7:31

I used six pack rods in my engine only because the engine already had them from the factory and I was trying to save money.

If I was doing the engine again I would not bother.

Sure they are strong. But they are heavy.

Six pack engines had to be externally balanced because of the weight of the rods and factory cast pistons.

I used KB pistons which are lighter than the factory pistons but when it came to having the crank internally balanced (which I wanted) they had to add a lot of weight to the crank.

Another thing to think about is rpm potential. These rods should be OK up to 6500rpm (some people say less) but that is a hell of a lot of mass to change direction many times a second. It stresses the rods and soaks up power.

So my advice is use the lightest rods that are strong enough for the power output and the rpm of your engine.

h_beam_rod.jpg
CAT H-Beam Racing connecting rods are good up to 800HP.
User avatar
dave-r
Grumpy Old Man
 
Posts: 9842
Joined: 12 Oct 2003 21:45
Location: North of the Tyne, England