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Das Beast: My E30 track / street build

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  • dvallis
    replied
    All parts here. Rebuild starting.

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  • ForcedFirebird
    replied
    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.
    Last edited by ForcedFirebird; 03-04-2021, 01:14 PM.

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  • kronus
    replied
    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.





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  • Digitalwave
    replied
    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.

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  • dvallis
    replied
    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






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  • citizen_insane
    replied
    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.

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  • dvallis
    replied
    Got the trap doors and baffles done. A bit more finish work and it goes to the welder this week.

    This is looking in from the bottom btw.

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  • dvallis
    replied
    No kidding. They're just temporary. Baffles will all be tig'd into a single unit and rivets drilled out.

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  • moatilliatta
    replied
    Id be cautious of rivets internally in the pan.

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  • dvallis
    replied
    Nice. Will be sure to check that.

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  • Digitalwave
    replied
    Originally posted by ForcedFirebird View Post
    Check the little locating tab on the rocker shafts isn't protruding too much out of the head. The VC has a little "bridge" there that holds the tab down. If that tab is crooked, or raised, then it interferes with the VC sealing. The cover needs very little torque on the nuts to seal. I rub a ~1/32" layer of goop on there too (Right Stuff).
    Just had to shout out the homie ForcedFirebird for this insight. I pulled my VC on Friday before racing at Homestead and sure enough, my rocker shaft "key" was sitting above the head by a good 2-3mm. Since I didn't want to adjust the rocker shaft positions, I just ground the key down slightly until it sat flush with the head. New gasket with a light skim of Right Stuff on both sides, and the VC did not leak one bit all weekend!

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  • dvallis
    replied
    Baffles in progress

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  • dvallis
    replied
    Oil pan is coming along nicely







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  • zwill23
    replied
    Cost effective in that they'll help keep your engine in one piece

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  • JehTehsus
    replied
    Originally posted by dvallis View Post
    New rods. Wife ironically says "Those look cost effective"

    I received somewhat similar comments when I installed my piston rings on the dining room table...

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