Das Beast: My E30 track / street build

[dvallis]

Engine machining is FINALLY done. Picking it up on Friday. Will be a lot more activity from then on.

[sonomabimmers]

Love this thread can't wait for more.


Tapatalk

[j5ady]

Cant wait!!!!!!!!!!!

[dvallis]

Das beast is back !!!!

Das Beast is BACK. Please play Kid Rock "Forever" while reading this post for maximum enjoyment. ("Ooh, I'm back, the the fog is lifted ...")

Here's the whole shebang we picked up from the machinist this morning. Work consisted of:

- Clearance pistons for M20B27 rods with M52B28 crank (big job)
- Hone rod ends for lower friction on pins
- Check block for flatness (did not need to be decked)
- Light hone on piston bores
- Measure crank journals for wear (still within spec)
- Fabricate crank seal spacer
- Check head for flatness
- Replace valve guides, seals
- Re-grind valve seats, lap valves



Crank seal spacer turned out really nice



Close up of the valve work



Here's the piston to crank clearance. Looks really tight but there is actually a few mm between piston and crank. We had to take a LOT off the piston skirts, but machinist knew enough about piston slap to keep the "tabs" you see on the sides. He's optimistic it will work.



Now that we're back in action with known tolerances I could order the last parts:

Valve springs: Schrick 0056 02 062 (outer), 0056 02 022 (inner). Provides over 600 lbs force at min height, versus 160 lbs for stock.
Main studs: ARP
Rod Bolts: ARP
Main crank bearings: BMW 11 21 1 265 459 (standard)
Rod bearings: BMW 11 24 1 284 849 (standard)
Rings: Deves 2297 (1.5 / 1.75 / 3.00 mm, 4 piece oil ring)
Wrist pin clips: BMW 07 11 9 934 460

Other parts ready for install:
Rocker arms: Heavy Duty, m20rarmHD, (IE)
Adjustable cam gear: Nuke, M20adjcamgearNUKE, (IE)
Head studs: ARP
Crank scraper: m20optray (IE)
Oil Pan Baffle: m20opd (IE)
Head gasket: Cometic MLS 0.120"

Whew. Wonder how all this goes back together? :devil:

[sonomabimmers]

Ohhhh yea [emoji33][emoji41]


Tapatalk

[j5ady]

:coolphoto:

[dvallis]

Engine rebuild continues. We are starting with the crank scraper. Here it is installed for a test fit. Cork oil gasket is underneath. Second gasket goes on top for the oil pan.



You can see the crank interferes with the scraper along each tab. This is because it's an M20B25 crank scraper, and we have an M52B28 crank. The M52 scraper was not guaranteed to fit our block.

Using a bastard file to remove material from each tab until there is 0.025" clearance to the crank. This will take a while. File, test fit, file, repeat. ;-) Stay tuned

[j5ady]

What is the purpose of the scraper?

[dvallis]

Crank scraper ... It scrapes the crank :devil:

Seriously though, when your engine is in operation the crank whips oil into a cloud of droplets contained in a swirling vortex around it. This "oil aerosol" can hold a quart or more of your engine oil. It causes drag on the crank and reduces oil in the crank case available for pumping. Combined with the high g-forces sustained in turns during racing, this can lead to oil starvation. A crank scraper in conjunction with crank case baffles can prevent oil starvation during racing.

[j5ady]

I swear I learn something new every day!

[dvallis]

All done. Close up of crank scraper clearance.



Rings and main bearings arrived. I splurged and got Deves rings.

[dvallis]

Oil Pump etc.

So, here's your chance to see what's inside an E30 oil pump. The damn things are No Longer Available from BMW, so online shops are selling them for $500 each. What a crock! Fortunately you will see there is not really anything to wear out, and the pump is really well built. Odds are you'll never replace it.

Here's the stock oil pump from Das Beast. Doesn't look too bad.



Here it is disassembled. Check out how beefy the pump gears are. Like I said, nothing really to wear out.



However, the pump can be improved on. Notice the small, sort of square oil intake hole. This supplies your ENTIRE ENGINE!



We can do better. Some time with a Dremmel tool and various files results in this: A much better oil intake.



Something we can't do very much about is the upstream oil intake. Once the pump sucks oil from the sump through the bigger hole we just made, it forces oil FOR THE ENTIRE ENGINE through THIS little hole. German engineers were having a bad day perhaps? I have seen the hole opened out into a "funnel" but honestly it won't change much. Oil still has to flow through the same diameter hole through the pump housing. And there is no room to work a Dremmel in there. Pass.



Here's the re-assembled oil pump. Looks pretty good.



One more way to improve the oil system is a sump baffle. Here's the inside of your oil pan. You can see there is a small baffle on the left side. However, when in a left hand turn under hard acceleration, oil will slosh out of the right side and starve your oil pump. That's especially a disaster for a turbo engines.



Enter the oil pan baffle. Surrounds the entire pump to prevent slosh. It fits nicely over the old baffle and bolts in place. Oil pump fits where my hand is. IE shipped the wrong nuts, so I won't show it bolted in place today.



On to weighing engine rotating components. New ARP rod bolts are nice and shiny. They all weigh the same within 1/10 of a gram. Also stronger than stock bolts and 5 grams less per pair.



The M20B27 rods, new bearings and rod bolts are all remarkably well balanced when combined. All within 0.5 g per cylinder, right out of the box.



And now the pistons. They all weighed in around 373 grams +- 1g except ONE. It weighs 366 grams. WTF? I can't run an engine with 8 grams imbalance!



The pistons look pretty much identical from side on. Can you tell which one is lighter?



On closer inspection the lighter piston was 0.050" shorter than the others. (1.900" vs. 1.950") That makes sense as I was able to take 4 grams off a test piston with just a file.



So, need to take the pistons back, have the other 5 shaved down to 1.900" and matched to 366 grams.

The adventure continues.

[MVincken]

That hole is exactly big enough for all the oil your engine needs. Keeping the volume the same will improve the oilflow. Having different volumes over the oilchannel will create pressure fluctuations. Which you don't want offcourse.
It's really suprising how little oil your engine really needs.
Improving the suck-up and oil baffle is offcourse never a bad thing.
Don't want to hate, i love your build. Keep up the good work

[dvallis]

Some more progress: Quick trip to Lowes for M7 nuts, bolts & washes resulted in the oil pan baffle finally getting installed. Looks good.



Using a proper tool to remove the incorrect valve springs (single spring Schrick 0002 02 090). Sears Craftsman has good tools, like this valve spring compressor, for decent prices.



Close up of the valve collets with spring under compression. Was hesitant about sticking my fingers in there. :devil: Seems like a flaky way to keep valve springs in place, but hey, it works.



You can't tell from the picture, but these Schrick springs (0056 02 062/022) have 610 lbs force when fully compressed, compared to about 250 lbs for the stock springs. Should snap the valves closed nicely with our 284/272 cam.



New heavy duty rockers with eccentrics installed. They look a lot more substantial than stock.



Head parts sorted, packed and ready for install. Not putting them on yet because we want to test valve to piston clearance when the head is installed on the block.



Now that the head is prepped, time to look at the ports. Here's the intake with a gasket in place. You can see how closely the gasket matches the port. Our E30 heads are actually really well designed. Not much to be done to improve the flow with porting and polishing. (Check over on E30 Tech. Lots of threads there).



That being said, here's the same gasket on the intake manifold. There's a fair amount of metal intruding into the flow area. Also notice the giant "bump" in the path of airflow.



Here's the same manifold port, honed out to match the gasket with the bump ground down. Looks pretty good. Five more to do but I am beat. It's 100F here in Texas with 90% humidity. Declaring victory and calling it a day.

[digger]

i think the 610 is Newtons (N) given shrick stuff is metric. when i had my head rebuild a while back we tried various springs the schricks were a little stiffer than stock but not by a huge amount. ended up settling on Eibachs. if you crucnh the numbers the schricks end up being 73lb on the seat so it would have to be N for that to make sense as thats the numbers i recall.