Das Beast: My E30 track / street build

[Northern]

Has anyone tapped their block for turbo oil return on the flat spot where the A/C compressor mounts? Or at one of these bolt holes?

(snip)

I drilled there for my iX's M20, and on both my 24V cars.



Drilled, Tapped, -10AN union with the back shaved down so it doesn't protrude into the block (I wasn't even close, but maybe an 89.6mm crank would need this?)

JB weld seals it and stops it from rotating when you ins/rem the drain.

[dvallis]

Did you go the simple pan baffle route, like the one from IE?

We did exactly that: An IE oil pan baffle. Even though I researched the HELL out of it, obviously that solution not up to the task, at 1 - 1.5 G lateral acceleration.



I'm not the first E30 track rat to be be here. Physics is physics. Anyone else running an E30 should have similar oil slosh. So what's up?

[Digitalwave]

It's totally oil slosh. Watch the G meter and oil pressure.



So ........ where are rest of the the E30 track rats? Need some informed opinions.

Sorry bud, I think you have a major oiling problem and probably have a spun/toasted bearing, or something similar. That is a scary low number. I would be concerned if a new motor was so much as idling at that pressure.

On my previous M20's final track event, I was getting down to ~20psi on high G left hand corners. Drained the oil afterwards, and the oil looked like a glitter bomb from a failed bearing. That motor had an IE baffle (only). I don't know how the baffle played into the failure or not. For all I know, that motor was on it's last life in any scenario. My new motor has both the IE baffle and an Ishira-Johnson crank scraper (windage tray), and it hasn't had any oil pressure issues after almost 3 full seasons of use. Again, I don't know if the I-J crank scraper has truly done much, this is just anecdotal. It's peace of mind, at least.

I would guess my car does 1.3ish sustained lateral G's on the Hoosier R7 slicks. The oil pressure does not *ever* drop below mid-50psi on track, even in long, sustained high G left-handed sweepers, at any RPM.

A quote from another member when I was diagnosing the failure of my last motor:

If you were dropping to 20psi in the corners you have trashed the bearings at least. Remember your "oil pressure" gauge is just a PRESSURE gauge that is reading pressure in the oil galley of the engine. When you slosh the oil away from the oil pump pickup in the pan the pump starts to suck AIR. With the residual oil coating the pump impeller the pump can actually move the enough AIR to still make PRESSURE in the oil galley, or at least pump some percentage of air along with the oil. AIR IS NOT A GOOD LUBRICANT!!! If you have ANY drop in oil pressure that does not correspond to a drop in engine speed you are SUCKING AIR and need to baffle the pan, run more oil, run an Accusump o something to fix the problem or you are going to trash your engine every time you go to the track!

[dvallis]

Excellent post. Thanks for sharing that knowledge. Luckily I enjoy wrenching so pulling the engine is Zen, not a hardship.

We removed the crank scraper during an oil leak extravaganza. Probably a bad idea in retrospect.

So tell me about your failed bearings. Were they main bearings, rod bearings ... ? What am I looking for, besides stripper glitter in the oil.

[Northern]

What are you running for oil level? Do M20 guys overfill a bit like with the 24v stuff?

[dvallis]

By the way, I'm getting oil pressure from where the idiot light pressure sender used to be. Seemed like a good spot. Will this location return accurate pressures?

[dvallis]

What are you running for oil level? Do M20 guys overfill a bit like with the 24v stuff?

Just middle to top of the dipstick marks. Checked before we went on track.

[dvallis]

Oil 'O Rama

Here are some interesting quotes from the SPEC30 guys on oil pressure:

"E30's have oil starvation issues in long sweepers. A crank scraper definitely helps"

"Hot oil pressure around 5psi at idle isn’t all that unusual"

"A good measure of bearing health is oil pressure hot at redline. >45 PSI with xW50 is Good. 40-50 psi, some wear. <30 psi, rebuild"

"E30 peak hot oil pressure is ~68 psi, set by oil pressure relief valve in block"

"E30 hot oil pressure is set by resistance to flow as seen by the pump"

"E30 flow resistance is from (1) Crank bearings (2) Rod bearings (3) Intermediate shaft bearings (4) Cam journals (5) Cam sprayer. Too much gap in either can cause low oil pressure"

"The stock oil pressure sensor location is good for measuring transient pressure losses at the pump, but less good for measuring transient pressure losses at the galley"

"Crank scraper is critical. The pump going dry in virtually every left turn was painfully obvious in the gauges."

"An Accusump is a bandaid. The real solution is not letting your oil pump suck air"

"There are folks that have been tracking their car for years with no scraper and have had no problems. That means that there’s aspects of this that still aren’t understood."

"I’m here to tell you that if you don’t have a crankscraper your pump is sucking air on most left turns"

"That being said, there’s guys w/o a scraper that have been running their motors hard for years. I’d like to say that I have an explanation for that apparent contradiction, but I don’t."

"Because our oil pump is a pos, remote oil filters and big oil coolers are a serious liability IF you have problems keeping your oil pump’s pickup submerged."

"Running a quart over is good idea, and not just for left turns. But too much yields blue smoke and fouled plugs"

"So much oil is going up to the top of the engine at high rpm, that it’s lowering the oil level in the pan."

"Prior to a crank scraper, my E30 would drop from normal 50+ PSI down to 16-19 in left sweepers. After adding a scraper but no other changes, the pressure would drop to perhaps 40-45.


So?


We're seeing 60 psi at redline, so I don't think the bearings are fried.

Definitely need a crank scraper.

Our oil cooler is oversized. That's more oil for the already puny pump to push.

Oil pressure sensor is remote from block (long hose). Will effect pressure reading if it drains

Turbo oil pressure regulator return to valve cover is a bad idea

Oil level was middle of the dipstick, which would have made it more susceptible to sucking air

[Digitalwave]

I didn't do a post-mortem on that motor because I had no interest in repairing it. I am assuming rod bearings, I think it's a more common failure than mains. 'bird can probably chime in with more info on M20 failures, he has much more experience than I (don't mean that as a dig).

That location for the oil pressure is fine, and it's advisable to remotely mount the sensor since they are prone to failure. Also, vibrations make the signal very jittery if the sensor is mounted on the block. Mine is mounted on the frame rail, separated by an ~18" -4AN line.

I run my oil level at a minimum of a "tick" above the full mark on the dipstick, usually more like 1/2 qt over full (which is probably 1/4" above the full mark, give or take).

[dvallis]

Then there's this horrible news from Metric Mechanic M20 Engine Booklet ....

"Under hard cornering (.9 g’s or greater) oil in the oil pan will migrate away from the oil pick-up. If the pick-up does not stay submerged in oil, it’s only a matter of seconds before the oil film between the rod bearings and the rod journal wipes away, the bearing goes out and the engine needs rebuilding. Hard long left corners are the most common culprit. During this kind of turn, oil in the pan is climbing up the right side of the block which is laying 20° from vertical. Meanwhile, at high rpms, the camshaft sprayer bar is over loading the head with oil - further robbing the pick-up. The longer the duration of a long left sweeper, the more oil drifts away from the pick-up. Once the oil pressure drops off seriously to 20 or 25 lbs., the rod bearings are already in trouble. By the time the oil light comes on at 7.5 lbs., its usually too late and a rod bearing is already gone."

A cheap fix to this problem is to over fill the engine with 1/2 to 1 quart of extra oil. But there is a downside of course. The extra oil slinging around the crank case causes added drag on the crankshaft consuming HP and makes the engine burn an excessive amount of oil.

[dvallis]

This is in our future. Will have to fab it.

[kronus]

don't bother with a scraper. made no difference in my experimentation. what you need is a baffle.

we had this issue with a race M30 and put deck restrictors in to keep more oil in the pan. much better after.

[Digitalwave]

don't bother with a scraper. made no difference in my experimentation. what you need is a baffle.

we had this issue with a race M30 and put deck restrictors in to keep more oil in the pan. much better after.

He already has a baffle in the pan.

[ForcedFirebird]

Haven't signed in lately, but we have lost enough engine over the years.

Oil drain in the block is fine, I've done it on past builds.

We used to just run 1qt over - that was fine for a stock engine and stock-ish suspension. Car got faster with new rules (like 4-6sec), lost pressure on a right sweeper, lost #4 rod bearing (rod and crank went in the bin).

Added teflon scraper, drilled holes on the stock side baffle, 86'd the level sensor, added pick up baffle, still 1qt over, shimmed the idle bypass (screen side) of the pump, shimmed the pressure relief valve. We see 90psi on cold start with 10w60, 25psi hot idle in the middle of a race. At 50hrs the motor was torn down and there was evidence of #2 & #7 main bearing wear, and want to say #5 rod bearing as well.

Remember, at 1g+, it's like laying your engine over. The cheap scrapers without the trap doors won't stop the oil from going up the side of the block.

[dvallis]

Remember, at 1g+, it's like laying your engine over. The cheap scrapers without the trap doors won't stop the oil from going up the side of the block.

John, thanks for tips. Much appreciated. Whats happening is clear now. Main flaw was running at 1/2 dipstick instead of 1 qt over. That exaggerated the slosh effect and explains 10 psi in corners, 60 psi WOT on straights. No scraper and non trap-door baffle added to the issue, And finally, dumping oil into the head from our turbo oil pressure regulator return is robbing oil from the sump when we need it. Pretty sure the turbo smoke was just return drain line being blocked by slosh. We're planning on going down the Moroso / Paul Poore / SPEC30 path, fabbing our own trap-door baffled high capacity oil pan. My buddy says "This engine is a frigging pricess!" He's used to American Iron, LoL.

What are your thoughts on going 0.060" for the valve spray bar, vs 0.120" stock? Worth it?