Das Beast: My E30 track / street build

[dvallis]

LoL, thats right. Piston rings rotate independently at about 1 rpm per engine 1000 rpm. Pretty sure ring clocking is irrelevant.

Cylinder walls were nice. No scoring.

We are reassembling this weekend.

[turbski]

Rings and things

We definitely have the right rings. Pistons are stock M20B25, we're using Deves 2297

From Deves web site


Per Deves, install oil oil scraper ring with notch down. Or "RTFM Sir" as I was told in the military.


Our oil rings are correct. 4 piece: top, middle, bottom and expander


This thread was useful. Root cause for his smoke was incorrect oil rings. Good tidbits below though.

jlevie: "When I build an engine I use Brad Penn 20-w50 oil, prime the oiling system with an electric drill, bring the engine up to temperature while bleeding the cooling system, and break it in by a 30 minute run at a constant 2500rpm. The rings will seat and the smoke will stop after 5-10 minutes."

blackbirdm3: "It took me a good 300 miles on my Datsun engine the first time I rebuilt it. I was also using Deves rings at the time. I knew exactly when the rings seated because the sound of the motor changed slightly and it started pulling like a freight train. If I remember correctly, the oil consumption was a bit on the high side till that point. I was also keeping the revs below 4k rpm, and didn't go above that till 500 miles, adding 1000 rpm for every 100 miles after that."

blackbirdm3: "Never use a synthetic oil for the first 3000 miles. I've been told that by various machinists and engine builders who know far more than I do."

exodus 2pt0: "When I rebuilt my 2.0T it smoked for about 300 miles until the rings seated. Compression went for 130psi after first start up to about 180psi around the time it stopped smoking.... Then again I did not lap the cylinders, due to being plasma coated, so that explains the 300 miles."

My conclusions
1. Five out of six scraper rings incorrectly installed
2. We incorrectly used synthetic oil during break-in
3. Some smoke on startup is normal after rebuild
4. Smoking should stop after 30 minute 2500 break-in

1. I was able to finally log back on today and saw your updates. Its almost like im looking at my own garage in your posts! head, intake, exhaust manifold and turbo all pulled off at once with some assistance from my wife and young son.
2. I was on the phone with Deves this morning trying to decipher (still) what piston rings are supposed to be on the s-eta. The gentleman I talked to very calmly said "Grab your calipers and give me the measurements on the thickness of the rings, start at the bottom and work up please" 10 minutes later I get an email with the exact same picture you posted above.

The work your doing is top notch and a big motivation to not light mine on fire where it sits lol keep up the great work.

[dvallis]

The work your doing is top notch and a big motivation to not light mine on fire where it sits lol keep up the great work.

LoL, step away from the matches. I've occasionally felt the same, but hey, it's a hobby. Glad the posts are helping out.

[dvallis]

More Lord Of the Rings

Started the bottom end rebuild today. Re-using the Deves rings as they're supposed to be pretty good.

Note clearly labelled instructions on the scraper ring. Can anyone say RTFM?!


We started measuring ring gaps for the compression and scraper ring in each piston. They were all 0.20 out of the box, good for a turbo build. Then we got to the scraper ring on #5. That's what we call "too much ring gap"


Oh well. Ring upgrade opportunity. We're still waiting for the head gasket from IE in any case.

[dvallis]

Decided to go with Hastings rings. Catalog is here.



M20B25 part number is 2C4762. Their description of the rings:

362 BF 3CR GI - Compression ring, barrel face, triple chrome coated, grey iron



401 SCRP PC GI - Scraper, phosphate, grey iron. (Napier type again. Note the notch and dot on top)



054 FV CR - 3 piece flex vent, steel rail, stainless steel expander, chrome coated
732 FV CR - 3 piece flex vent, steel rail, stainless steel expander, chrome coated



That's it. I now know far too much about M20 rings.

[Digitalwave]

As do I, and I will remember this if I ever assemble an M20 myself.

[dvallis]

New rings arrived. Can anyone spot the problem.


The compression rings were 5mm thick. LoL, supposed to be 1.5mm. That sucks. Amazon vendor fail. Next time I'll just order from Summit as usual.

[dvallis]

Got the rings from Summit. Arrived in a unopened box. That's better. Now we just need the new head gasket. ETA is Friday.

[dvallis]

Back at it this weekend. Installing the new rings.

Measuring the ring gap. Using 0.018 for compression rings. 0.020 for scraper rings. Oil rings are gapped to 0.020 stock (we checked)


Small adjustments. You can't un-gap rings


Rings installed and clocked. Hastings have a 3 piece oil ring. Note the napier scraper, notch down. Compression rings are 'molly coated with a square profile. Can go either way.


Ring compression tool. It's important to press this down hard against the block when sliding the pistons in. You don't want the rings to pop out.


Piston installed. Valve reliefs are the right way :-)


Installing rod caps. Note the oil pan mating surface still needs to be scraped.


Repeat six times. We'll start on the head next week.

In the meantime, clutch stop broke on the M5, so we made a new one. Two flat washers welded to a 3/8" carriage bolt.



End product. Very solid.

[Digitalwave]

Let's get this bitch tuned!!!

[dvallis]

No kidding. Back at it on Monday...

[dvallis]

Bottom of 3 piece oil ring got jammed and bent on piston 6. Had to wait for new ring set. It's important to keep even pressure on the ring compression tool against the head while sliding the piston in. Definitely a two man job. All done now.



Snugging the rod end cap bolts before torquing them down. It's a freaking weird torque spec: "15 ft-lbs then then another 70 degrees" Ends up being about 50 ft-lbs per my digital torque wrench. Which makes more sense as the M10 spec is 40 ft-lbs.



We trimmed the crank scraper to make installation and removal 100X easier, i.e. even frigging possible to clear the installed oil pump. Before anyone loses their mind, yes, we know. We only lose two of the 12 crank lobe scrapers right over the oil pan baffle. No big deal.



We used a bit of spray tack to hold the bottom gasket to the oil pan. Scraper is being used to press everything down evenly.



Oil pump and pressure relief valve in place



Final installation process is (1) gasket on top of scraper, (2) hold those two against block, (3) maneuver oil pan with tacked gasket into place, (4) Turn, angle, rotate and slide it all into place. Then put in all the bolts. Torque everything. Whew. Bolts back by the clutch are a b@#$ to access. Requires a wrist with three joints. I was doing the final torquing and Robs says "It's Miller Time up here. Sucks to be you under there." LoL



So, it's possible to do an entire engine job without pulling the block, removing the front end or steering rack. Just takes a couple of guys and lots of patience. Top end will go quick as we're just re-assembling not fixing, engineering or re-building anything. Pretty damn easy compared to what we just finished.

[dvallis]

Motor is back on its mounts



Driveshaft, shifter, transmission mount etc. reattached



Downpipe hooked up again.



The intake manifold has been on my mind lately. Since we had to take everything off, I've been contemplating replacing it. Several of you, and even my tuner thought we =might= starve cylinder 6. Valid point. Can't know for sure without a flow bench or blowing up the engine on a dyno.



I went down the Google rathole, looking for an off-the-shelf E30 turbo intake manifold. Believe it or not, besides these eBay hack jobs, there is is nothing out there.



I've had this lump sitting on a table in the media room for a month. Found several posts here and elsewhere of guys making 500+ HP with it under boost. We know it flows pretty damn good (lots of posts out there on it) has nice runners and generally just works. Flow can be equalized and improved ~25% with extrude honing. See this post. Guy went from 190 to 240 cfm. But, that's $500 and I don't have a local supplier for the service. Soooooo .... we're going to use it. Better safe than sorry. Tuner will be happy.



Taking it to Enigma tomorrow, along with the valve cover. They'll media blast and dual stage powder coat both. Should end up looking like this.

[ForcedFirebird]

Would you mind taking a pic of the inside of your intake manifold (the fabricated one)?

Interested if there's horns or raised radii bell-mouths. If you take dimensions, ,Digger may be able to do some CFD for ya.

[dvallis]

Here's the inside of the plenum. No baffles or bell mouths. Slight raised lip on each runner.



Dimensions to scale here. Would definitely be interesting to see some CFD.