Block groove above main bearing?

[CNC BLOCKS]

I questioned it last year.

viewtopic.php?f=1&t=31464

Here is quote I did last year

Those grooves were also used for piston oilers as well!!!

Having those grooves in the block and drilling 2 holes in the bearings that have a goove that is already pressurised with oil it really seems like a waste of time drilling the extra holes JMO.

Pin oiling you need the grooves.

[Kevin Johnson]

27 responses 900 views and not one reason as to why this groove is there!!!

Page 3, paragraph "1." of Meernik. I am not transcribing SAE papers. It makes sense that GM Research would be seen in GM motors.

[robert1]

I see one paragraph not 3 pgs.

[Chipped tooth]

I have a small air die grinder with a black smith looking jig affixed to it, it has a 1/4 round bit with a way to set depth by sliding bit in and out of the chuck, I used to notch the main about 3/4 from center and around .060 deep on the trailing edge.

Then drill a hole in the bearing for the extra oil feed notch

It was a old Pontiac trick I was shown, I did it on Chevy and mopar after that.

Not shure if it helped but I never hurt parts, I haven't used it in years though

If I find it ill post some pics of it, its crude but functional.

[Walter R. Malik]

27 responses 900 views and not one reason as to why this groove is there!!!

REALLY ...?
Must be selective reading,

[robert1]

Perhaps you'd like to point out why.

[Warp Speed]

Perhaps you'd like to point out why.

The Jeopardy soundtrack should be playing right now!
LOL

RWtech could probably tell you exactly why. I've only known it as a way to feed various oiling architectures but......?


I'm still waiting for someone to answer my bearing groove comment..............

It may help answer why you wouldn't want to introduce the oil at 3 o'clock?

[Kevin Johnson]

I see one paragraph not 3 pgs.

When you download the paper the numbering of the paper itself runs to seven pages. That is the page reference system I am using. Maybe you are thinking about the abstract or summary for the paper on the SAE website.

SAE 932785 from Choi, Min and Han discusses oil aeration in bearing oil supply. There is a lot of good information in the paper on pressure distributions and a very important note on the effect of the shock when registration switches. This paper cites Meernik and I believe the GM LS designs help to ameliorate this. I also downloaded several of the other papers in the bibilography.

[robert1]

Perhaps you'd like to point out why.

The Jeopardy soundtrack should be playing right now!
LOL

RWtech could probably tell you exactly why. I've only known it as a way to feed various oiling architectures but......?


I'm still waiting for someone to answer my bearing groove comment..............

It may help answer why you wouldn't want to introduce the oil at 3 o'clock?

I think RW must have gotten tired of the banter. I don't see him around much anymore.

[Kevin Johnson]

So why do they use a partial groove on 1 2 4 5 mains, but use a full half groove on 3?

More even oil distribution on the thrust bearing surfaces and presumably to try to prevent over oiling of the center two bays via ejected oil.

It is interesting to compare the orientation and sizes of the relief slots on the upper and lower thrust bearing surfaces moving from the earlier LS bearings to the LS7 bearings (which also have full half slots on the other mains).

Aside: when you compare other earlier systems oiling to the LS7, say, keep in mind that the endurance testing for the LS7 probably plopped it on peak rpms at peak output for hundreds of hours on end (ala solution looking for a problem -- found).

[robert1]

So are we any closer to an answer to this question?

[Kevin Johnson]

So are we any closer to an answer to this question?

I thought this was answered. The groove helps with oil distribution at sustained high rpms. Look at the BMW S62. That was developed at least 15 years ago so it is not bleeding edge. It is a solution arrived at by OEMs that have the resources to sit an engine at 6600 rpms for hundreds of hours at peak output.

[Warp Speed]

So are we any closer to an answer to this question?

Evidently not!!!!! HAHAHAHAHAHAHAHA

[Kevin Johnson]

So are we any closer to an answer to this question?

Evidently not!!!!! HAHAHAHAHAHAHAHA

Ok.

So why did Porsche use it 40 years ago in the 928?

Why did Mercedes use it 40 years ago in the M100?



PLEASE enlighten us about the solution looking for a problem.

[Warp Speed]

So are we any closer to an answer to this question?

Evidently not!!!!! HAHAHAHAHAHAHAHA

Ok.

So why did Porsche use it 40 years ago in the 928?

Why did Mercedes use it 40 years ago in the M100?



PLEASE enlighten us about the solution looking for a problem.

First of all, the phrase you keep using "solution looking for a problem" wasn't mine.
Second, I already stated my views, and it is to free up oiling architecture in different combinations. Be it main oiling or accessory oiling such as piston oilers ect. Maybe it is driven by cost saving along with the oiling deal, as that would be a great place to save some material over a couple million pieces. As I said earlier, RWtech would probably know exactly why in the case of the LS engine.
I'm still waiting to hear a clear explanation as to why the varying oil feed grooves in the main bearings?