i have like .040" of clearance between my rods, i thing that is a little much. it is a new fordged 2 piece rear main seal crank and forged h-beam eagle rods. i know that GM calls for .015". will it be ok to run it like it is or should i have it checked out.

 

If you're referring to rod side clearance, .040 is way too much unless you're running aluminum rods.

The downside of running .040 is a lot of oil will get thrown back on the crank creating a windage drag. It may effect oil pressure too, but the wider clearance won't necessarily hurt the engine.

To my knowledge the only way to tighten rod side clearance is to use a different crank or different (wider) rods. There are some that claim the crank had be welded up and then turned down to tighten the clearance, but I don't trust that method.

Jake

 

GM spec is ~.015". My recent motor has .020" which everyone claims is acceptable.
Seems to me that .040" would have a negative effect on oil pressure.

 

what year is your block, lt1 uses a 1 piece rear main

 

.020 is OK but .040 is too much.

 

it is a lt1 block but it has been converted to a two piece rear main seal. i bought it this way from a guy on ls1tech.com and every thing looks awsome but the side play in the connecting rods.

 

How is the thrust clearance on the crank? .040" is a good amount but it's not a huge problem the rods are just going to talk to each other more. Is that .040" found on all of the sets of rods or just one? Did you find this with feeler guages?

Bret

 

well when i took apart the rods and crank i noticed it and it looked about .040" , but after putting the crank and rods back in after checking all the bearings i used a feeler gauge between the two rods and it was only ay .027". i don't think it is that big of a problem. i should have used the feeler gauge before i made this post but i wanted to see what kind of problem i was running into. and my thrust on my crank is good it is at .004".

 

i guess you put your good eye on that, huh

 

I put together an engine @ .028; all tensed up about it. No problems.

 

Thrust is on the low side but more guys don't pry the **** out of it both ways to get the max reading. At .027" I wouldn't worry too much about the rods.

Bret

 

i believe that the gm book calls for .003" to .006" on the crank thrust. and no i didn't pry really hard just enough to get the crank to move.