Really would like to get more than 1000miles until my next failure so need some advise from someone who might have seen this before. I will take it back to the machine shop but before I do would like to know what I might expect them to say. Pics and info included below.

Car is a C5Z, block is an LS3, 4" K1 crank FM 152M coated bearings, compstar rods ACL coated bearings and Wiseco pistons. Its blown with an F1A and makes 800 rwhp. Engine was built by a reputable builder LSx builder. Not sure if it's coincidence but my friend picked up the 1200rwhp LSA record holding CTSV engine that had a similar bearing problem with the same builder.

Housing bore: 2.7513-2.7515
Mains Clearance: 1,2,3,4 =.0021 and #5=.0022

I suspect this was an oil issue and a few things could have stacked up to create the hot short on the #4 main. Ever since the breakin, the oil pressure would never go above 40psi, cold or hot, idle or WOT. Ran 35psi hot at idle and would go to 40psi tops, 30,40 and 50 weight oil didn't matter much either. Oil pump is a Melling HV with he lower (10psi?) blue spring. I really think I should have seen more than 40psi even with the blue spring.

A couple of weeks ago was on the dyno and made 3 good pulls, after the 3rd the low oil light came on and was a quart low so added VR1 straight 50 on top of the 10w-40 Castrol that was in there. Drove it home where it sat until the next weekend when I changed the oil to 100% VR1 straight 50. Didn't change the filter (stupid) because I didn't have any replacement cartridges for the 4" Canton billet filter.

The next day I went to a track day and was running hot at 250F water and 260F oil. When it got to 250F I shut it down. I have been plagued by a bad cooling system which is likely the lack of flow from an electric water pump but I do have a 3" DeWitts radiator and integrated oil cooler which helped. I'm going to ditch the EWP and have an Evans on the way but that is another topic. 800 hp hot lapping on a raod course in a vette in the summer is probably not the best with an EWP but I think I learned that the hard way.

The second time out, oil pressure dropped to 7 psi after one lap so knew something happened, luckily was on the last straight before the pits so coasted in. Inspected the filter and had a crap ton of bearing flakes.

#1,3 and 5 were fine, #2 was slightly worn showing tin but #4 was beat to hell. What gets me is the rod bearings look even better than the good mains. Would have thought an oil problem would show more in the #7 or 8 rod bearings. Also the #4 cap has a blue heat ring from all the friction, can I reuse it and if not can I use a new one?

What are my options now and what can I do to keep this from happening again? Align bore, set clearances, new bearings, reuse crank, red Melling spring, what oil weight/type for .002", keep water under 230 and oil under 250?

Thanks.

Toasted #4


Warped


Crank, can't feel any scratches with fingernail


Housing, got lucky and didn't spin


Main cap HAZ


Other bearings


Other caps

 

Conventional oil won't live at 260*, it will break down. Better get an oil cooler to get the temps down and go to a synthetic.

 

I would take it back to the builder and see what they say. You definitely should have seen more oil pressure with the HV pump and those clearances on coated bearings. Take a look at the back of the bearings and see if they're all the same or if there is a .001" bearing snuck in there on accident.

 

Yeah, something doesn't sound right with those clearances and for the oil pressure to be that low.

Did you check to make sure that's correct with a manual gauge?

 

I think the clearances were too loose. Did they give you a build sheet with the specs?

 

Should I install the oil cooler after or before the radiator cooler?

Wow that would suck, didn't think of that so will check the others. The #4 is a standard so if the others were .001, that would be a problem.

Yes early on during break in verified with the 1/8 npt port on the lingenfelter oil filter adapter block.

Yes the build sheet is what I ref for the clearances stated. Thought that .002 on the mains was what many run for a aluminum block forged setup. Is the coated graphite taken into account?

Could one of the DOD ports leaked that bad? I drilled and tapped them but noticed oil on the top of the set screws. Still the valley cover plate should have not let any oil pressure past. I'm going to lock tight those setscrew plugs in this time.

 

No they aren't. Thats what my mains are at. Mine are all .0021, Rods are .0025. same pump with blue spring. Hot oil pressure 50-55, 70-75 WOT. 10w 30.

Maybe the bypass on the pump was stuck open? I took my pump apart before installing it, found some cast flashing particles in it that needed to be cleaned out. I also checked to make sure the bypass valve moved freely.

If the car never made over 40 pounds of oil pressure from the get go, you should have tore it down. Check the cam retaining plate for signs of leaking if you reused an old one. Other than that I have no idea.

At 43 seconds you can get a clip of my oil pressure at idle, this is not all the way up to temp. Looks to be about 60 PSI.

 

Should I install the oil cooler after or before the radiator cooler? I would go after so it can get the most heat out before it hits the cooler.
If max pressure was at 40# even cold there is something wrong. Did the oil pump get cleaned after the earlier bearing issue? The by-pass may be stuck open. Since it idles at 35# and peaks at 40# I would be suspicious that it's not closing.
If this is reoccurring check across the main saddles to see if they are flat. When a bearing gets really hot it can shrink the aluminum to where it's high at the block wall/pan rail and lower in the center by the bearing. The bearing clearance will change when it the engine warms up if it isn't flat and seated cold.

 

I should have started a thread a long time ago checking if this was normal, guess not and I learned the hard way. Everytime I drove my Denali I would wish the vette had the same oil pressure, close to what you have, 40-45 hot idle and 60-65 at 6500.

Still need to inspect the pump to see if the relief valve is cracked open and that would actually be the best find. The front retainer plate was new and an ls3 style with the countersunk screws.

I am still confused as to why, if I had crap for pressure to begin with, why #4 was hot shorted and the other bearings were ok? I thought #4 and 5 were the first to get oil. What if the DOD provisions were leaking?

At 33 seconds you can see the oil pressure during the dyno a few weeks ago.

 

You need to look at the entire oil system. From the oil pan to the mains.

Your clearances are fine.
Make sure you don't have a leak in the cam area.

Tim at the Car Shop Inc has a few vetts that he has worked with to fix the problems they were having like yours.

It is most likely not one thing but a few little things that are together a big problem. There is no way you should be running anything over 10-30 with your clearances and those oil temps are telling you it has been eating it self up for a while.

I never see over 210 with mine with no cooler in 90 degree ambient

Tim

 

Just checked the oil pump and the o-ring and releif valve seem fine. Appears to be something after the pump.

Cam journals and cam bearings look and measure out good, exactly the same as 1000 miles ago.

LS7 lifters, are not blocking the galleries.

Still thinking DOD provisions not plugged well enough. If each one leaked 2 psi that would be 16psi.

What is the part number for the LS3 cam retainer plate? Will try another new one. Shop supplied the last one so I "assume" it was new.

 

Check the lifter bore to lifter clearance while you have it apart because that can create a big loss.
Also make sure the barbell was in correct with a good o-ring and no damage to the bore where it seals.
Make sure that the mating surface for the oil pump port on the block to pump is flat and the surface is in good shape since there isn't a gasket it needs to mate very good.

 

Do you know of anyone using RTV sealant on the pump to block?

 

Here is what I use

 

what size lines do you have going to your cooler.

I have a gauge on mine before the remote filter and in the back of the intake just to make sure that they are the same.

Tim

 

Nice, 86hatch, I kinda wish GM o-ringed the pump outlet like Schumann did.

 

Schumann has a bunch of nice features. Just put my pump on tonight. Ball bearing bypass, delete the pickup tube o-ring. few other things.
Lots of stuff melling says is not important Schumann has addressed.

Tim

 

what is wrong with the screen. The screen on oem and moroso pickups is way to tight and makes it tough to get the oil to the pump.

Tim

 

If it makes it thru the pump without blowing it up the filter will catch it. The secret is to not have crap in the engine.

Schumanns has spent a lot of time on the dyno with these and found that the stock screens were limiting the flow.

Tim

 

"Should I install the oil cooler after or before the radiator cooler?"

remove the added heat load from the radiator by using a remote cooler..