wet sump engine oil control, a thread.

[Series8217]

Please post up the results! I'll be very interested to hear them.

It's worth mentioning that oil control applies to more than just the sump, I assume you have a PVC system of some kind? It's possible that the PCV is pulling oil from the valve covers, do you notice any knock retard or knock sensor action at the same time? Being that you're based in California, I'm guessing you're still using a stock ECU/PCM? are you able to adequately log spark advance and knock retard?

Good luck at the track!

Stock PCV. It might be related to the oil consumption, but there is for sure a windage problem. My lifters clatter like crazy if I go above 6000 RPM during or right after a high G corner. Unless my lifters are junk, the clatter is a sign of air mixed into the oil.

Here's some frightening data from this weekend.

X axis engine RPM, Y axis is oil pressure. The color axis is lateral acceleration... green is 0 G's, yellow/red is right turns, and blue is left turns. Dark blue is ~1.4 to 1.5G. This track configuration is CCW hence the small number of yellow/red data points.

What's VERY concerning is the oil pressure dropping to less than 30 psi above 3500 RPM in left corners. Worse, once I get above 6000 RPM after exiting the corner, I feel the engine bog down a bit, blue smoke comes out the exhaust, and the lifters start to clatter. The lifter clatter is a dead giveaway of oil foaming happening. Serious oil windage explains the power loss as well.

I don't know if oil is accumulating in the heads and draining down onto the crank, or just getting whipped up by the crankshaft.

bad-news.png (244.06 KiB) Viewed 225 times

[eHoward]

Never thought I'd see the use of visual analytics on RFT

[ericjon262]

bad-news.png

Is this a 3.4 DOHC?

it is, it would be great to see if/how much a crank scraper helps.

I'm unfamilliar with the oil drains on a LQ1, anyone have pictures of how the heads drain to through the block?


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one of the things I was considering, was to plug the oil drains on the underside of the cam tunnel. this would force oil from the top end to flow from to the oil pan via the front and rear of the valley, instead of onto the top of the crank. which could have significant performance improvements. FWIW, NASCAR engines have flooded cam tunnels, but they also have dry sumps, the problems that arise for us, is that the oil has to get back to the sump, and then get pumped back up top, if the oil out of the sump exceeds the flowrate of oil going in from the drains, we have a problem. if the cam tunnel is truly flooded, we can fill it from above while assembling the engine and determine how much oil is held there, and adjust fill as necessary to maintain the suction covered, but then we may overfill the pan to the degree that the seals have oil on them when the engine isn't running, which could lead to leaks, something we also don't want. it would be awesome if there was an easy way to see how much oil flowed through the different galleries so that we could make reasonable assumptions about how much oil needs to drain from the top end.

anyone want to sponsor me with dry sump parts so I can quit thinking about it?

[Series8217]

it is, it would be great to see if/how much a crank scraper helps.

I'm unfamilliar with the oil drains on a LQ1, anyone have pictures of how the heads drain to through the block?

There are drainback passages on the outside perimeter of the block at end of the heads. Where the passages enter the crankcase, there's a baffle to coerce the oil to flow along the block wall instead of getting whipped up in the crank.

[ericjon262]

it probably wouldn't be too terribly hard to install a crank scraper with the engine still in the car. it wouldn't be fun to trim it for a close fit, but not impossible.

[ericjon262]

Depends on what rods are being used. The steel scrapers I was getting weren't close enough to the stock rods to require any modification, but the teflon versions obviously were.

are they close enough to the rods and crank to be effective? ideally, they need to be just short of touching, thats frequently easier said than done, I was building a very custom scraper for my engine, I will be again soon, but first I need to fuck up some thieves.

[The Dark Side of Will]

What's VERY concerning is the oil pressure dropping to less than 30 psi above 3500 RPM in left corners. Worse, once I get above 6000 RPM after exiting the corner, I feel the engine bog down a bit, blue smoke comes out the exhaust, and the lifters start to clatter. The lifter clatter is a dead giveaway of oil foaming happening. Serious oil windage explains the power loss as well.

I don't know if oil is accumulating in the heads and draining down onto the crank, or just getting whipped up by the crankshaft.

Of course blue smoke means the engine is burning oil. Oil can make it into the chambers via valve stem seals, the PCV system or going past the rings.
In your circumstance, I'd suspect it's just getting too much oil on the cylinder walls for the rings to clear adequately.

During a 1g corner, the angle of the surface of the oil in the pan wants to be 45 degrees from horizontal. That probably allows bulk oil to contact the rotating assembly, which would make a lot of oil foam in a very short time.

[Series8217]

I just ordered a teflon crank scraper from Ishihara-Johnson. Kevin is also going to help me with some improvements to the windage tray, but I need to source a spare that he can do the work on.

[SappySE107]

I hadn't talked to Kevin in a long time, but he left a message asking about an LQ1 scraper so I figured it had to be you. I might have a windage tray here, ill have to look.

[ericjon262]

I just ordered a teflon crank scraper from Ishihara-Johnson. Kevin is also going to help me with some improvements to the windage tray, but I need to source a spare that he can do the work on.

Kevin replied to my thread on speed talk, I think he thinks we're the same guy... Lol.


I look forward to hearing how it works out, especially since you have the capability to provide very detailed data of how well the changes work!


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In one of my earlier posts I mentioned wanting a crank scraper on the leading edge of the crank, and then worrying about oil piling up on the scraper and not draining, I started considering that the scraper could literally be acting like a pump in this scenario, and actively pushing oil into the sump. Thoughts?

[Series8217]

I hadn't talked to Kevin in a long time, but he left a message asking about an LQ1 scraper so I figured it had to be you. I might have a windage tray here, ill have to look.

Yep he emailed me today and said he left you a message! Please let me know if you find one. Thanks!

[Series8217]

In one of my earlier posts I mentioned wanting a crank scraper on the leading edge of the crank, and then worrying about oil piling up on the scraper and not draining, I started considering that the scraper could literally be acting like a pump in this scenario, and actively pushing oil into the sump. Thoughts?

The scraper goes on the upstroke side of the crank so oil drains off it back into the pan.

[SappySE107]

I found 6 3400 and 0 3.4 DOHC. I had 2 at one point and would have kept 1 for the bowtie block potentially, so i am at a loss.

[ericjon262]

In one of my earlier posts I mentioned wanting a crank scraper on the leading edge of the crank, and then worrying about oil piling up on the scraper and not draining, I started considering that the scraper could literally be acting like a pump in this scenario, and actively pushing oil into the sump. Thoughts?

The scraper goes on the upstroke side of the crank so oil drains off it back into the pan.

as long as it's installed tangent/radial(with the scraper more or less vertical) to the rotation of the crank, does it really matter? I'm asking as a serious question, it definitely complicates the installation, but it's not impossible to do.