Thread: L67 Connecting Rod Length

Okay, I have searched until Im blue in the face and I cannot find anything. Alldata has nothing either. I thought I had a Haynes manual around here that had the info in it, but I cant find it either. The really bad part is that I had the information at one point, had it wrote down and now I cant even find that.

So, can anyone tell me what the connecting rod length is for the L67?

No one knows?

When I read this, I reached for my Haynes. But, it doesn't cover the L67.

I poked at my SI manual but didn't have much time. I'll look some more when I get the chance.

I know I had it before, I had it wrote down and I had thought I got it out of a Haynes manual, but I guess your post blows that out of the water.

If you come up with something, let me know. Ive been looking for probably the last week or so and have not found anything. Who would have thought such a piece of information would be so hard to find.

Originally Posted by SyntheticShield

I know I had it before, I had it wrote down and I had thought I got it out of a Haynes manual, but I guess your post blows that out of the water.

I'm not saying it's not in any Haynes. Just that it's not in mine. Mine covers Impalas and Montes up to 2003 (someone gave it to me for free, and so little changed in the 2004 year that I find it useful). The L67 wasn't in Impalas and Montes until 2004, so there won't be anything about it in there.

Does it show the connecting rod length for motor your manual covers? I dont know about the lengths, but the only other difference I am aware of between the NA and SC motors are that the wrist pins are different sizes.

It would seem it has everything but that.

Yeah, thats what Ive been running into. I can find just about every tolerance, every dimension, every statistic except what the rod lengths are.

Since I am about to build a new bottom end for the Cutlass soon I will dig out a connecting rod and measure everything for you. My GM service manual says nothing either.

What is up with that? Is it like some cold war star wars defense initiative secret or something?

Rod length would be the same for an L32 if I'm not mistaken.

I have a bunch of engine parts on my shelves in the garage, and I know I have some rods sitting there as well I can measure one for you.

What do they do for measurement numbers, center of the wrist pin hole to the center of the crank bore? Thats what I would do if I were to measure them. I can get you pretty close that way I believe.

~F~

Well I'd like to have both overall and center to center, but when you buy connecting rods they use center to center for the measurements.

I just took an L67 connecting rod and measured all around and here are the important specs.

Big End - 2.37378 - 2.3745 (GM Spec)
Small End/ID of Pin Bushing - .906 +/- .0005 (as measured)
Edge of Big end to edge of Small end-bushing is 4.000"

After doing a little math you see that these connecting rods have a 5.94" center to center which is a common GM length among other engines.

The machined width at the big and small end of the rod is .843" +/- .001

OUTSTANDING!! Thank you Dave, I really appreciate that.

No, not exactly, but now that you mention it, that would be a good way to do so though I would be concerned about throwing off the overall reciprocating geometry.

It was a piece of information that I needed in order to look into some other things I was considering. Nothing concrete at this point, just some ideas I had floating around.

Awesome Dave, thanks. You saved me from getting dirty today. LOL

~F~