Burnt LSX block Main Bearing
Burnt LSX block Main Bearing Need a little help here guys. Got a GM LSX block with a Eagle rotating assembly. Crank is 4.00, 427 overall ci. Motor only has about a hour on it. The mains are gone! Caps and block show rainbow from overheat. Rod bearings are clean. We think the builder put the wrong bearing in. They are Clevite 77 -a1 mb3592hf std. The crank is std also. The front bearing was pushed out. Does anyone have the p# for the correct clevite bearing. Or any other ideas? Thanks for the help.
The MB3592HF is the #3 & MB3591H is bearings 1,2,4,5. These are the correct bearings for the LS block. The complete bearing pack is #MS2199H
Did the builder give you a measurment for the bearing clearance that the mains were assembled at?
Also the Eagle cranks many times have taper in the main journals. The journals can also not be in perfect alignment with each other. This will burn up a bearing fast. When ever using an Eagle crank it is best to have the crank checked out by a reputable crank grinder to ensur the crank is straight and journals are round.
Did the builder give you a measurment for the bearing clearance that the mains were assembled at?
Also the Eagle cranks many times have taper in the main journals. The journals can also not be in perfect alignment with each other. This will burn up a bearing fast. When ever using an Eagle crank it is best to have the crank checked out by a reputable crank grinder to ensur the crank is straight and journals are round.
Thanks for the quick response bryan. We're trying to get a hold of the builder now for crank clearance numbers. Never gonna know about the crank...it's gonna have to be turned now. We are switching to a more reputable builder to cut and check the crank.
Man, I hate to see you having issues. Like Brian, I would be interested to see the bearing clearances. Hopefully it will clean up being turned 10.
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Got an LS2 stroker with an Eagle crank,same problem.We DID however,in this instance,determine what caused it and I wouldnt be suprised if you had a similar issue.Here is a pic of #1 main,less than 1000miles,bearings welded and just starting to spin in the block.
Here is a pic of the crank,all the mains are trashed,look at #4 !
Here is a pic of the crank,all the mains are trashed,look at #4 !
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That's really unfortunate. It's the #1 issue that we see when customers call with oil pressure concerns. We've had a customer install a new o-ring three times with the same result. It showed up at our facility to be fixed, and the o-ring was pinched. Sometimes the smallest of parts can cause catastrophic damage.
Let us know if we can help you out.
Trevor
Texas Speed & Performance
Let us know if we can help you out.
Trevor
Texas Speed & Performance
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FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
Need a little help here guys. Got a GM LSX block with a Eagle rotating assembly. Crank is 4.00, 427 overall ci. Motor only has about a hour on it. The mains are gone! Caps and block show rainbow from overheat. Rod bearings are clean. We think the builder put the wrong bearing in. They are Clevite 77 -a1 mb3592hf std. The crank is std also. The front bearing was pushed out. Does anyone have the p# for the correct clevite bearing. Or any other ideas? Thanks for the help.
There is always a little taper on most cranks with fillets but the LS1 has about an inch across the main journals and the main bearings are about .780-.750 across so they have .100 to either side of themselves where they don't even touch the crank. If you have a LOT of taper you could still be shutting off a lot of oil flow so you'd need to have that addressed and fixed by a good crank grinder.
FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
It probably goes without saying but we also line hone every LSX with the appropriate fasteners as well as some are out of spec. and would spin the mains with any crank if you just put them together.
well, we put the motor through a couple heat cycles. Still good pressure. Made one pass and shut it down cause the pressure dropped. Only spun to 7k. The o ring was perfect when we tore it down. No pinch or cut. Builder said he did mic the crank. When we asked if he just did the center of the journal. Dead silence. Didn't check for taper. After talking to bryan, we looked at the bearings again. You could see the taper in the crank by the wear in the bearing. They are making good on the motor and paying for all parts and labor. Thanks for the help guys.
