largecar379

I was digging around in my parts and thought I'd compare con rods from different 928 engines.

below is a pic of two rods. one from a US spec 4.5L, the other from a 5.0L.

I was surprised in the differences.

the 4.5 rod is beefier, with nice thick I-beams.

the 5.0 rod looks like something home-made, not very heavy duty, and lousy castings on the sides of the beams.

weights for the rods are about the same, although I do not have a good set of scales to compare.

both rods have the same pin/ bearing diameters and hole to hole lengths, so one might make the assumption that the 4.5 rod maybe a better rod......?

Comments?????

Check it out.......

--Russ

Daniel Dudley

The rod on the right has a sharper bend at the base of the rod next to the bolt head. Stress point ? Rod on the left is beefier top and bottom at those spots by the bolts. Looks to be a substancial increase.

BC

The rods after 88 were like the one on the left. The right side is more like all prior.

largecar379

I had no clue about the rods, so has anyone had any experience with the question of:

Which is better?

I'm curious if there are any appreciable differences......

thanks--

--Russ

BC

Some early 928 rods are considered "forged" though people speak of "powder forged" which seems better than the cast ones that came out of my 89 motor. So I put in rods that were more like the forged ones and used ARP rod bolts.

mark kibort

there are a couple of variations of the type on the right as well. we put scots engine together with a mix of both. all balanced tip and tail. the main difference was the thicknss of the rod at the wrist pin hole. I think a search can find the pics.

mk