rod bearing clearances

[Randy954]

Well I just put my rods back in and I measured the rod bearing clearances on the plastic gauge it measured .006 i believe. Is this ok? Im running a 4g64 crank with 1g rods and aftermarket pistons.

 

[Randy954]

anyone???

 

[Randy954]

note: there is a tiny tiny bit of side to side and up and down play but its very small and thats with no oil or grease... Is this normal?

 

[donniekak]

No that is to much clearance. If you run that engine it will spin a bearing the instant it starts. The clearance should be .002".

 

[92AWDHX40]

Do you have a manual it will tell you the specs for your engine.

 

[Randy954]

No that is to much clearance. If you run that engine it will spin a bearing the instant it starts. The clearance should be .002".

So what do i need to do? they were standard bearings.

 

[Randy954]

No that is to much clearance. If you run that engine it will spin a bearing the instant it starts. The clearance should be .002".

Ok well i just got off the phone with showdown motorsports whos shop builds 1000hp+ dsms and he said that .002 is ENTIRELY too tight.. Mine is .006 which he said is on the loose side but i should be fine if i run thicker oil. He said my clearances are .003 top and .003 bottom which gives me .006. He also said he runs his race motors at .008 and they are fine

 

[IceMinion]

Yeah, I have heard that .002 was a too tight, and that you can have greater tolerances almost up to .010

I really wish there would be more definitive information online.

The more room, the thicker the oil right?

Anyone?

 

[Randy954]

Yeah, I have heard that .002 was a too tight, and that you can have greater tolerances almost up to .010

I really wish there would be more definitive information online.

The more room, the thicker the oil right?

Anyone?

yes thicker oil. From what I hear people run bigger clearances so more oil can get in there and cool better.

 

[Randy954]

doublepost

 

[donniekak]

For a stock rebuild .002" is what these engines run. I run .003" for a 4-500 whp build. The service manual lists .004" as the max . Huge clearances are fine for a track only high power, high rev build. If your in traffic idling, .006" is to much room for your oil pump to fill at 750 rpm's. What are your goals?

 

[Randy954]

Its a 2.3 stroker setup. Im running a 6bolt 4g63 block, 4g64 crank, 7bolt head, 1g rods, wiseco .60over stroker pistons and an evo 3 16g. Im looking for about 350-400hp. So should I get oversized bearings?

 

[donniekak]

Oversized bearings come in .01" incriments. What it looks like to me is that a shop polished your crank out of spec. If you want to use oversized bearings you'll need to have the crank ground. I would just get another crank.

 

[e85_4g63]

Who did the machine work on the crank? The machinist should have told you the correct bearings to order. Did you have the crank cut?

 

[Randy954]

The crank was done about 10k miles ago. So I didnt have it redone. Do I need to?
history:
I bought this car at a junkyard and they nor I had any idea what was done to it before I bought it. Im guess the mileage is between 10k because I know the guy who owned it before did the work or had it done. And between him and me it was only about 10k miles. I bought this car thinking it was stock for about $2300 and it turned out to be a semi built stroker motor with a brand new e3 16g. I thought i got lucky when I found out what it really had for such a cheap price. they didnt even know if it was turbo or not when I got there. But anyways this rebuild has taken me over 6months instead of the 1month i was expecting.

 

[G-UNIT]

If you have the crank out I would take it to Castillos Crankshaft in LaMirada and have him measure and look at it. If it needs work I would not let anyone else but them do it.