Das Beast: My E30 track / street build

[dvallis]

Heliwhat?

Did some prep on the bottom end. Block threads for the oil pan bolts got a good cleaning out (gunk removal) and checked with an m6x1 tap. Two of the damn holes in those aluminum bearing carriers front and back were wonky. Par for the course on M20s I suspose.

Bolts in photo are just to keep dirt out. M6x25 are too long and will bottom out. We've got a new set of M6x20 on the way. Will give max thread with our crank scraper plus oil pan stack.



Decided to helicoil them both



Drill out the hole. Screw in helicoil. Knock out the tang & extract from hole. Both hold torque now.

[Elysian]

Love the 3d printed ring tool.

[dvallis]

Lord Of the Rings

Feeler gauges organized. I hate dicking around with all of them on a key ring.



Insert ring



Seat with handy ring tool



Check the gap



Grind, just a bit. Drill turns toward INSIDE of ring



Measure again. Repeat until within spec. We used 0.022" for the 2nd ring per Total Seal.



Ring set installed on piston. Tops are "gapless" which is really two rings with big gaps, but they overlap and interlock. 2nd ring seated correctly with notch inside and down. Bottom is a 3 ring sandwich.



Ubiquitous blue tape holds clocked rings in place.



Repeat 6 times. Done.

[Digitalwave]

Keep 'em coming!

[dvallis]

Original piston assembly weight 256.4g



New piston assembly weight 200.7g. Looks like we're saving about 0.75 lb on the rotating mass.



Rod bearing shells are the right size. Unlike the 1st build :-)



We dorked around forever installing the first set of rod pin clips. You know the drill: sore thumbs, clips flying across the room, crawling around the floor looking for lost clips. So, we made a tool that does it in 10 seconds.

Get a thin wall tube about 0.85" in diameter
Cut it off about 4" long
Get a solid plunger that fits inside the tube
Insert ring in tube a shown



Insert wrist pin temporarily. It gives the clip a surface to push against.



Put tube perpendicular to piston with gap up



Insert plunger. Press down with smooth firm motion. Ring will click when it seats



Voila



Slightly remove pin. Insert rod. Repeat on opposite side.



More next time

[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.

[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.

[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.

[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

[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.

[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."

[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]

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

[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]

All parts here. Rebuild starting.