Oil squirters, cause of spun bearings?

[John Monnin]

I found a REALLY interesting DSM page that theorized that 2nd gen DSM crank walk is caused by press in oil squirters that can stick open and starve thrust bearings at low idle.

Please read this article completely before posting on this thread.

http://www.magnusmotorsports.com/tech/crankwalk.htm

DSM owners often bypass thier clutch switches so they can start thier cars w/o applying the clutch, this reduces the load on the trust bearings. 1st Gen owners do not seem to have this problem.

1st Gen DSMs use bolt in style oil squiters squirters.



But 2nd Gen DSMs use tiny press-in oil squirters that are easier to contaminate and get stuck open easier. Oil squiters have check valves that only open at high pressure to prevent taking oil away form bearings at low RPMS when the oil pressure is low and the oil squiters are not needed to cool pistons.



Here is a detailed picture of a 2nd gen DSM press-in oil squiters



A 3s short-block uses 12 oil squirters that are very similar to this.
6 in the block and 6 in the rods.

See this pictures of 3s oil Squirter, it also gets its oil supply from main bearings



If multiple oil squirters are sticking open at low RPM would that be enough to starve bearings?

Do aftermarket 3S rods like Pauter and Crower use oil squirters?
From pictures on GT-Pro, 3SX and Dynamic's Webpages it looks like aftermarket rods do not have oil squirters.



If Aftermarket rods don't use oil squirter's converting to 1st gen DSM squirters might be good insurance.

I know several people who have had bearings fail, re-built the engines, checked clearances and then failed the same bearings in less than a year. This might explain that.

[Gatecrasher]

You know, that's a really interesting theory. I had never thought that the DSM crankwalk problem might in some way be applicable to our bearing problems.

It would be great for someone to disassemble a wrecked block and dissect the oil squirters. For that matter, what would it take to have a spent block cross sectioned on an industrial band saw? Actually seeing the oil and coolant passages would be a huge benefit. I believe Magnus did this with a couple of DSM blocks.

Judging by the pictures though, I don't really see how we could retrofit DSM squirters. It looks like everything is in the wrong location. would it really be that harmful to just eliminate them completely?

I've never seen an aftermarket rod with an oil squirter. This doesn't mean they don't exist, but it would surprise me if they were out there.

[John Monnin]

Originally posted by Gatecrasher
It would be great for someone to disassemble a wrecked block and dissect the oil squirters. For that matter, what would it take to have a spent block cross sectioned on an industrial band saw? Actually seeing the oil and coolant passages would be a huge benefit. I believe Magnus did this with a couple of DSM blocks.

If anyone within a 200-300 miles of Southbend Indiana has a damaged 3S TT block, I can pick it up and get it sectioned at work, I think the industrial band saw in the lab is big enough. If not I have friends at several local machine shops that would do it cheap.

We sectioned my buddies spare GN head a few weeks ago so he could figure out how much porting he could do w/o getting in-trouble.

P.S. Grand Nationals have HORRIBLE heads compared to a 3S. I will post some pictures later tonight. Cast iron, small ports, bends in the ports, HUGE holes in exhaus ports for EGR.
The best mod Sam probably did was grinding off the huge cast valve guides and replace them with slim pressed in guides.

[Multiades]

... so as extra insurance (since spinning two rod bearings in a row) I now use thicker engine oil. 15w50 is very helpful for anyone with a 60k + engine as bearing clearances start to open up. Thicker oil is harder to push through the squirter oriface too.

I think the added cooling from under-piston jets should not be just thrown away by removing them. Cast pistons, with their inferior thermal transfer, could probably benefit from such cooling -- especially as thermal loads become higher in modified engines.

-Chris

[John Monnin]

Originally posted by Gatecrasher
.......Judging by the pictures though, I don't really see how we could retrofit DSM squirters. It looks like everything is in the wrong location. would it really be that harmful to just eliminate them completely?

I've never seen an aftermarket rod with an oil squirter. This doesn't mean they don't exist, but it would surprise me if they were out there.

The DSM oil squiter is probably not right for 3S block

DSM 1st gen Squirter


3S TT block


If we section a block we could determine if a better location was avialable, I like these squirters on a 300Z, But I have no Idea if there is an oil passage close enouhg to use this.



It would be interesting to see if a better quality squirter was available like this one for 944's

http://www.kellymoss.com/pages/partspages/17_002.htm

Oil squirters remove heat from psitons which helps to prevent detonation. I don't feel confident enough to remove them completely.

One other (expensive) idea could address oil volumn concerns too, convert to a drysump sytem that has enough volumn that you dont care if the oil squiters are stuck open. Replace the stock powersteering pump with a drysump oil pump that also has a powersteering pump attached



Or even a half assed drysump system could be used that would provide oil for new oil squirters, turbos, remote oil filters and oil coolers. This way all the stock oil pump would have to do is provide oil to crank, rods and heads.

I just realized I am getting into the practicality level of putting a Skyline transmission in a 3S, It never hurts to dream

P.S.

Originally posted by Multiades
... so as extra insurance (since spinning two rod bearings in a row) I now use thicker engine oil. 15w50 is very helpful for anyone with a 60k + engine as bearing clearances start to open up. Thicker oil is harder to push through the squirter oriface too.
-Chris

I used 20W50 at the NG03 Road Course. ALL of the local Porche Club guys strongly suggested this would give extra protection if oil starvation happened because of the banking. The car ran well and the lifters seemed quiet so I kept using this grade. The first day that the temperature was below freezing I got lifter tick (with 3rd gen lifters) so bad I thought I had jumped teeth on the timing belt. As soon as the engine warmed up the tick went away. A quick change to 10W30 eliminated this problem. I think the thicker oil is a little too tough to get through lifters. I might try 10W40 next.

[J-Ville VR-4]

Originally posted by John Monnin
P.S.


I used 20W50 at the NG03 Road Course. ALL of the local Porche Club guys strongly suggested this would give extra protection if oil starvation happened because of the banking. The car ran well and the lifters seemed quiet so I kept using this grade. The first day that the temperature was below freezing I got lifter tick (with 3rd gen lifters) so bad I thought I had jumped teeth on the timing belt. As soon as the engine warmed up the tick went away. A quick change to 10W30 eliminated this problem. I think the thicker oil is a little too tough to get through lifters. I might try 10W40 next.

I use 20W-50 and I get a bit of lifter tick on cold startups sometimes. Its a little too thick to get there right away, but its usually only for a second or two, so I'm happy with it.

[92vr4ny]

Right now I am using Mobil 1 0w-40 and very impressed with it. Is there any reason that should be a problem?

[Macky]

Originally posted by 92vr4ny
Right now I am using Mobil 1 0w-40 and very impressed with it. Is there any reason that should be a problem?

i dont see any reason as to why it should.

the oil squirters on the SRT-4 are almost identical to the DSM ones, although its a little closer to the sleeve. i dont know if that helps in any way though

[jackhammer]

I think this is worth looking into. Or at least warrants oil jet replacement at rebuild time.

It does seem like most of the bearing failures are coming from high mileage original motors, or motors that have been "rebuilt". I personally have not heard of a spun bearing on a fresh factory new short block, not to say it has not happened.

The oil jets get "coked up" or dirty over time, and not replaced at rebuild time, which means they still have the same mileage as the motor had before the rebuild. A simple "boiling" of the block while rebuilding probably won't clean the jets very good.

I have also never heard of anybody replacing the oil jets. I say since they are available, replace them at rebuild time just for good measures.

Of course cutting up a block (and heads for that matter) would probably shed a lot of light on a lot of different unknowns with this motor.

[Gatecrasher]

I have two TRASHED NA heads I can donate for cross sectioning. They're physically intact, but have about a 1/4" of sludge just caked on them.

One of the local MI guys blew his engine a couple months ago. It scored one of the bores pretty good, so he decided to just replace it with a factory short block. I'll ask him if he still has the old one and would be interested in parting with it.