Oiling problems?

[jamsilvia]

OK, so here's the story - maybe someone can shed some light:

I've got an ITS S13. The car has always run high oil temps, so I've got an oil cooler installed in front of the radiator. I also had noticed a good bit of oil starvation on right handers, so I've also got an accusump plumbed in.

I ran a few races at Summit Point, and things seemed to be OK. Recently, however, the oil pressure even at idle would jump wildly (like a nearly instant 20 PSI drop with another quick bump back up to where it was). When I'd hold revs with the motor, it would be a similar story.

So, I took the motor out. I'm not comfortable running it like that, and it was acting up last time out at Nelson (with very high oil temps: > 280 after only 4 laps and poor pressure in the long right handers). I replaced: oil pickup, oil pump gears, oil pump cover, and the pressure relief. I rechecked all of the bearings on the bottom end and in the cams for excessive wear that may cause a large clearance and a oil "leak" point. Everything looked good. I reassembled and reinstalled.

It still seems to have the same issue. At least with some circles in front of the house. I'm going to the Glen this weekend, so I may have more information about at-speed running. However, the idle is still pretty wacky.

Letsee - FYI, I also run Mobil1 20w50. The gauges are Nordskog pro series.

So a few questions:
- Any ideas on what could cause the weird jumpy pressures?
- Anyone else find they need to run an accusump for hard right handers?
- Have others seen high oil temps with these motors?

I'm a bit disgruntled recently with the car. The original motor in it was never opened and ran 3 seasons (including 2 - 12 hour enduros, a 13 hour, and a couple 4 hour enduros). When I ran the car, the motor had > 175k miles on it, ran with no oil cooler, no accusump. And it ran for that long without issue! Despite the additions, it seems like I'm going backwards with reliability!

Any help is appreciated.

Thanks, all (especially if you read this whole thing!!)
joe

[joeg]

Are the gauges electric or mechanical?

Does it otherwise run well and how are the water temps?

[CCARVER]

Guages would be suspect.
Also check the oil squirters next time the motor is out.
I had one that was cracked causing weird oil issues.

Another option is keep running junk yard motors and not worry with it. Keep a spare on the lift.

Carver

[jamsilvia]

Gauges are electrical, BTW. And having the gauge be the issue would not surprise me. I've had 7 Nordskog gauges so far in this car. Of them, I've returned all but 2 now (for a grand total of 5 returns), all of them with different problems.

As for water temps, GENERALLY, they're good (sub 200). But the last time I had the car out at Nelson, I was getting in the 220 range w/o traffic.

Sooo....if I keep running junkyard motors - should I keep the accusump and oil cooler on there? Or do most people run without it and are a-OK.

(The one person I had spoken to, Kryder, said he's not had problems, and he runs no cooler, no sump - just a biggie radiator).

joe

[DavidM]

I'm in ITA with the single cam motor so may not be the same, but I have an oil cooler with no accusump. An oil cooler is pretty much a necessity for racing. I don't think a lot of ITA 240 guys are running a sump, though I could be wrong. I make sure the oil level is a little above F on the dipstick (which is what Bob said), but that's about it. I don't have an oil temp gauge at the moment so don't know what temps I'm running.

My water temps are 180-190 on hot days, seeing 200 when I'm behind someone. I'll see 170-180 on cooler days and maybe even in the 160s at the ARRC in November. Put in the biggest radiator you can fit. I don't have a mechanical fan on the motor so that opens up a lot of room. I added in an electrical fan that I use when on grid or sitting for some reason and also to cool down after a session.

I've got a Cendyne electrical oil pressure gauge and I think mine is starting to act up as well. It'll spike to 80 psi for no apparent reason and hold there then drop back down to normal pressures again for no apparent reason. If you want to see if it's the gauge, remove the electrical sender and hook up a mechanical gauge to see if you see the same thing.

David

[ecugrad]

If it's any consolation, my 96 240sx ALWAYS looses pressure on long right handers. T3 (Fishhook) at Rockingham. This was measured on both electrical and mechanical OPG's

Hell its worth a shot to try a inexpensive mechanical OPG.

[ScottOk]

I run an '89 with a single cam, no sump or cooler, Only a big radiator. I have no mechanical fan and I rarely run over 210 even in traffic (at Sebring in July). I have never seen the oil pressure spike or drop. I run an Autometer mechanical guage. I agree with the earlier posts to run a mechanical and see what's happening before tearing the car apart.

[jamsilvia]

Thanks, everyone, for their input!!!

Looks like I'll be diagnosing a bad gauge or bad pressure sender at this point.

I ran at the Glen this weekend (fun one). I just ignored the bouncy gauge, and when it was wet and cool out, the motor ran in the sub-180's. On Sunday, it got hot, and racing was tight. Temps crept up over 210. Going by what you guys see, that still seems a little high.

I also took a look at the other 240's there. They all had bigger radiators than I have. So I think that, along with the advice here for my gauges, is the first thing to look into for keeping the car cool.


Thanks again, all, for the input!
joe

[CCARVER]

Any updates?

[jamsilvia]

Update:

So, attempting to check one more thing off the whole running really hot list, I decided to get the car dyno'd with a wideband O2. I've got no adjustable FPR or anything - so it really was a dyno run to see if I was too lean. Well, sure enough - I ran very close to 14:1 from 4500 on up. Although that's stoich, that is apparently really lean for a race engine. Ah-ha! Superb! I have a fix on the way, and I plan on re-running the dyno to see if we can get closer to a good AFR. Some testing after that should (hopefully!) show temps staying lower.

As far as the oiling being jumpy - I'm pretty convinced it is now the gauge or sender. I am going to swap the gauge with a friend's to see how the gauge reacts...and I'm ordering a new sender to test that too. More updates as I get that working....

Thanks again, guys!
joe

[chuck baader]

Put in mechanical gages...they work or not:026: Chuck