Block groove above main bearing?

[Kevin Johnson]

HAHAHA............I don't need to become a historian to figure out whats up!!!

I live it every day!

So, go over that again, why did they change the grooves for the LS7?

Which grooves???

You have mentioned both the feed groove in the bearing, and also the slots/grooves in the thrust surface.

Have you actually looked at the LS7 bearings yet? And compared them to those used in the earlier LS engines? That is what I am hinting at.

So, in answer to your question: all of them.

It is worthwhile looking at the others I mentioned as well.

[Pontiac_Puller]

GM 8.1L

[Warp Speed]

Have you actually looked at the LS7 bearings yet? And compared them to those used in the earlier LS engines? That is what I am hinting at.

So, in answer to your question: all of them.

It is worthwhile looking at the others I mentioned as well.

All of the LS bearings I have seen were the same as far as oiling architecture, but that has only been for the LS7 and the LS NASCAR spec engine.
Maybe you could point the differences out and I could probably explain what's up.
Where are we going with this?

[Kevin Johnson]

Have you actually looked at the LS7 bearings yet? And compared them to those used in the earlier LS engines? That is what I am hinting at.

So, in answer to your question: all of them.

It is worthwhile looking at the others I mentioned as well.

All of the LS bearings I have seen were the same as far as oiling architecture, but that has only been for the LS7 and the LS NASCAR spec engine.
Maybe you could point the differences out and I could probably explain what's up.
Where are we going with this?

This picture shows the earlier LS main bearings:
http://www.crank-scrapers.com/LS/3_4%25 ... ngines.jpg

This picture shows the LS7 upper main shells installed in an LS7 block:
http://www.crank-scrapers.com/LS/DSCF4702.jpg

This picture shows a close-up of an LS7 thrust set:
http://www.crank-scrapers.com/LS/3_4%25 ... 20LS_1.jpg

I suspect that it is possible to use earlier bearings in later engines and vice-versa but that would be beside the point.


This image shows the mains for the 2014 LT1:
http://stwot.motortrend.com/files/2012/ ... rings1.jpg
http://wot.motortrend.com/next-gen-lt1- ... z2Q9o5sNPg
Note the 6600 rpm fuel cut-off; after 10 million hours of sims and feedback on the outliers with the LS7, the rpms are a bit more conservative.

The LS7 had a 7000 rpm redline (fuel cut-off at 7100 -- 500 rpm higher than the LT1): http://www.corvettemuseum.org/specs/2006/LS7.shtml

[Walter R. Malik]

AND, what they all have in common is that the OEM main bearing oil clearance is rather on the tight side.

[wyrmrider]

By extension - should we be putting the primary oil feed hole for the main bearings on the lead side of the groove and not having it in the center at all?

works for me
top is just a big oilleak

[robert1]

The slots on the i.d. are a different animal.

[Warp Speed]

AND, what they all have in common is that the OEM main bearing oil clearance is rather on the tight side.

Compared to??????

The 80's......yes they are! LOL

[Warp Speed]

Have you actually looked at the LS7 bearings yet? And compared them to those used in the earlier LS engines? That is what I am hinting at.

So, in answer to your question: all of them.

It is worthwhile looking at the others I mentioned as well.

All of the LS bearings I have seen were the same as far as oiling architecture, but that has only been for the LS7 and the LS NASCAR spec engine.
Maybe you could point the differences out and I could probably explain what's up.
Where are we going with this?

This picture shows the earlier LS main bearings:
http://www.crank-scrapers.com/LS/3_4%25 ... ngines.jpg

This picture shows the LS7 upper main shells installed in an LS7 block:
http://www.crank-scrapers.com/LS/DSCF4702.jpg

This picture shows a close-up of an LS7 thrust set:
http://www.crank-scrapers.com/LS/3_4%25 ... 20LS_1.jpg

I suspect that it is possible to use earlier bearings in later engines and vice-versa but that would be beside the point.


This image shows the mains for the 2014 LT1:
http://stwot.motortrend.com/files/2012/ ... rings1.jpg
http://wot.motortrend.com/next-gen-lt1- ... z2Q9o5sNPg
Note the 6600 rpm fuel cut-off; after 10 million hours of sims and feedback on the outliers with the LS7, the rpms are a bit more conservative.

The LS7 had a 7000 rpm redline (fuel cut-off at 7100 -- 500 rpm higher than the LT1): http://www.corvettemuseum.org/specs/2006/LS7.shtml

I believe you may have the bearings backward. Both of the factory LS7 engines I have been in both came with a partial groove in the bearing.
I beleiev the differance in thrust face grooves may be an update from earlier versions to accomodate the added pressure of a manual trans?

[Kevin Johnson]

I believe you may have the bearings backward. Both of the factory LS7 engines I have been in both came with a partial groove in the bearing.
I beleiev the differance in thrust face grooves may be an update from earlier versions to accomodate the added pressure of a manual trans?

Well worth looking into very, very carefully, I think.

When I looked at LS7 exhaust rocker arms I found at least three distinct variants, for example.

The exhaust valve failures may be tied into partially burned abrasive deposits on sodium valves supercooling during warmup causing progressive wear in the guides *. Excessive oil thrown up on the cylinder walls might be a source versus any excess drawn through the guides. Since earlier generations of LS engines with sodium valves did not suffer the dropped valve problem this might be an attempted tweak to perturb the system back to more forgiving behavior and get rid of the outliers.

* There is a patent addressing this problem in other sodium valves (not GM) in the prior art section.

[miniv8]

Relax, thread's not that old... its a good thread.

I think this is just as much of a personal preference as the location of the cam bearing oil holes.

Where do you clock your hole in the cam bearings? and why would you not want the main bearing to be oriented the same way?

Because of the parting line?