rods

[backwoodsE30]

One of the techs at VAC wants me to use 135mm rods apposed to the 130mm rods that I have. His reasoning is that a 2 valve head takes longer to fill so it should remain near and at TDC for as long as possible.
Here's the run down, VAC stage 3 head with 288/272 cam, hone extruded intake manifold, #19 injectors, miller psik and war chip, full header back, custom CP 10.8:1 85mm pistons, M52 crank. What should I do?

[CarsSuck]

If you're using custom pistons, its a no brainer, use the longer rod. It's a more ideal ratio, futhermore, it's the length bmw has used in the m20b25, m52, s50 and s52. The only reason people use eta rods in their 2.7/2.8 strokers is because they're cheap.

[backwoodsE30]

ok thanks for the input. 135mm it is

[Cinnabar325is]

One of the techs at VAC wants me to use 135mm rods apposed to the 130mm rods that I have. His reasoning is that a 2 valve head takes longer to fill so it should remain near and at TDC for as long as possible.
Here's the run down, VAC stage 3 head with 288/272 cam, hone extruded intake manifold, #19 injectors, miller psik and war chip, full header back, custom CP 10.8:1 85mm pistons, M52 crank. What should I do?

That's quite a motor, do the 85mm pistons make it a 2.9? And is CP a brand? Where did you have the intake manifold extrude honed and what did it cost if you don't mind saying?

[backwoodsE30]

Yeah it will be a 2.9l. CP is a brand that VAC carries. IE did the manifold $600 I think

[TobyB]

Smokey Yunik agreed- stuff the longest rod in there that you can without
compromising ring seal....
Free torque, no real drawbacks...

t