Das Beast: My E30 track / street build

[citizen_insane]

Sorry to hear about the engine and turbo, that's some really bad luck.

I don't think the crank scraper was necessarily the root cause for the low oil pressure, I have one on my car with an IE style baffle and I also saw oil pressure as low as 17 PSI at Atlanta Motorsports Park (very long left hand 4th gear sweeper). I haven't seen any glitter in my oil, but we'll see if my lead content goes way up in my next oil analysis. I got a trap door baffle from AAF to install when it warms up a bit, so hopefully that's enough. I'd rather not go down the full custom oil pan route you're going, it must be possible to keep these engines alive on track, the Spec E30 guys are doing it.

[dvallis]

Hey, thanks for checking in. After the whole tear down we know there were multiple compounding root causes:

1. We ran at normal oil level, not 1/2 over
2. Blockage in turbo oil feed
3. Stock oil pan
4. No crank scraper

Frankly, running a race engine $xxt happens. :-)

New JE pistons and IHJ scraper are here

[Digitalwave]

I think most SpecE30 guys just overfill by a lot. They might have a baffled pan. Only a few have crank scrapers. Every once in a while you see Accusumps, but I don't think those do much.

I have a baffled pan and crank scraper, and I overfill by 1/4 - 1/2 quart. Never seen lower than 50psi on track in any corner at Sebring, Homestead, PBIR, Daytona, or Road Atlanta.

[kronus]

scrapers don't do much for oil starvation. how much oil do you think there could possibly be covering the crank counterweights?? there's no way it would be enough to make a difference when your sump is sucking air.

accusumps work. I've seen a bunch of them in lemons over the years. cheap insurance, and easy to see work if you plumb a gauge to it. we have a 3L one waiting to go in.


install deck restrictors. install a baffled pan. run over full. fundamentally, these motors rely on gravity to drain oil back into the sump. during long lefts, if you're pulling enough lateral g, it doesn't.

[ForcedFirebird]

I've lost two motors in the lasy ~8yr of enuro racing, both on long right handers, not lefts (two weeks ago, we were able to save #3 motor, just ate the rod bearings).

When pulling over 1g the oil most certainly goes up the side of the block, and since the engine is leaned over, the oil easily goes up the passenger side - essentially at 1g, it's like rolling your car over about 45°. It's not like it happens all of a sudden - if you use a fast acting digital or non-fluid filled gauge and watch the oil blipping at +1g when the oil level to the stock "full" line. Motor #3 was losing pressure over a 3hr period before we brought the car in. We had a spare motor on the trailer with a blown HG, so I grabbed the rod bearings out of that motor, stuck them in the car through the oil pan,and continued to race the 8hrs left of the 14hr. When the car came in for low pressure, I immediately checked the level and it was just over the stock "full" line. At full tilt, we tend to burn about 15gal fuel and .5 qt oil every 2hr, obviously someone forgot to check in the hot pit :/

No, the scraper wasn't designed to remove the oil and put it in the pan, the scraping action of the scraper is to reduce windage. When Kevin at IJ invented that scraper, it was a two fold design, scrape the oil off the crank and create a baffle for the entire side of the engine that it leans to. Scraping the oil off the crank does two things - one is lighten the crank (yes, it's only ~15-30gm, but at 7k rpm...), the second is to keep suspension to a minimum. It seems to work as well as knife edging the crank to reduce wind resistance and cut through the oil mist that's saturated the engine interior. If the windage tray wasn't useful (along with the oil drain-back tubes dumping directly in the pan), BMW wouldn't have changed the design with the introduction of the next generation(s) of the baby six. In street car-situations, you have a lot more vacuum on the crank case, helping the oil droplets fall quickly (as well as decreased wind resistance for the crank/pistons), but in racing situations, there's hardly vacuum since the engine is usually under acceleration (TB open to atmo).

I would love to put accusumps in our cars, but they cost too many points. :/

EDIT: We change the bearings every other year, provided there's no issues, which is about 75-85hr. For a spec car to see that kind of mileage, it would have to race approx 30 weekends to match our hours. Most spec races are 30-45min, and FL is the only region that has 4 races per weekend, everywhere else has two AFAIK. So, each hour of an enduro is like 1.3 45min sprints, so a single 14hr race is like doing 18 sprints back-to-back in a single day. Most regions have about 4-6 spec races an entire calendar year.

[dvallis]

All parts here. Rebuild starting.

[Northern]

By scraping the crank, it's effectively minimizing how much oil can be flung back up into the engine, and maximizing how much is going down in at least the general direction of the sump.

[dvallis]

Trap door large sump oil pan is done. Nice job by Ernie's Welding.

[zwill23]

Looks nice! Did you maintain the same overall pan height as stock? I forget if you're running a heavy duty skid plate, but that seems like some good insurance on track.

[dvallis]

We kept about the same depth, just scaled out. Wanted to keep the same flow dynamics around the oil pump pickup. I'm sure Hans has some engineering into it.

We refer to Hans a lot in the garage. Usually "F@#$ HANS! You HAD to put that bolt THERE?"

If it gets to needing a skid plate, Crew Chief's reply is "Stay on the track, idiot."

[moatilliatta]

I would take. Flat edge to the gasket surface to confirm flat before bolting it up. I do this even if a baffle is welded and most get hit on a big belt sander.

[ForcedFirebird]

It's not the lawn mowing I am concerned about with the oil pan, debris is also a culprit. Besides "two off" is a legal pass, even in TT. :p

[halesyeah]

Hey amazing build thread. Been following it the last few years in awe. I want to thank you for documenting the process so thoroughly, especially all the mistakes. I'm putting together a 2.9L stroker and got the bottom end together a few weeks ago. Put the oil pan on and then remembered your whole oil ring fiasco. I of course couldn't remember if I checked my 2nd rings to see if they were directional. Nothing in the documentation about it. So reluctantly I pulled the oil pan and scraper and 2 gaskets and checked the pistons one by one. Sure enough #5 and #6 rings were upside down. And they are clearly marked TOP on the rings. So thanks for saving me from trying to diagnose a smoking engine by putting all the good and bad in this thread.

[dvallis]

Glad to have helped. Rob and I frankly knew nothing about M20 engines when this whole adventure started, so it's been fun sharing the learning along the way. We have a "Wall Of Shame" for all the funny screw-ups: Bent valves, upside down rings, "plastic shard of doom" that lunched the first turbo. Will have some more good details with this next bottom end re-assembly.

[dvallis]

Started on the rebuild today.

Did a light de-glaze on the bores


Started installing the rings. Oil ring was good out of the box with 0.0015" clearance.



2nd ring needs 0.0022" per total seal specs.


After checking online we realized ring gapping tools come in three varieties: cheap junk, over priced and unavailable. We built our own. Made the platform large enough to support the entire ring, decent thickness aluminum for rigidity with a clamp point underneath for the vice. Variable speed AC drill finishes it off. Looking forward to trying it next time.