M30 swap for my Olive Drab Vert!

[jim325]

Retorque the head studs after u drive it a little. This what I did. I didn't use copper gasket spray tho. But I'm not currently having problems with mine, I already blew a head gasket :p

[RagtopE30]

M30 swap for my Olive Drab Vert!

Thanks Jim. I still have your hat!

[Good & Tight]

Matt, you get it back together yet..?

[RagtopE30]

M30 swap for my Olive Drab Vert!

Yes sir. I got her back up and running yesterday. I drove her home very lightly and I will drive her back to the shop today. Once she has cooled down I will do one last torque on the studs. Then I have an appointment tomorrow evening at the dyno and I have acquired a boost controller so I will either blow my engine or I will show up to the vintage with some pretty good numbers.

[george graves]

Why do you think your HG leaked?

[RagtopE30]

I wasn't able to convince my machinist to follow Otis's advice on the hg prep and installation.

[george graves]

I wasn't able to convince my machinist to follow Otis's advice on the hg prep and installation.

A skim and decking of the head? Sorry I missed that bit of info.

[RagtopE30]

No the head was completely gone through at the time of assembly. The hg did great while I was running NA. The leak only showed up when boost above 10psi happened. Otis recommended separating the individual layers of the Mls hg and coating each side with copper sealant spray. Then to step torque the head studs with multiple passes per value with a resting time in between each pass. All of that was ignored and the machinist said it was unnecessary, which it was for a NA application but boost is a different animal

[RagtopE30]

Ok I got the car running yesterday and spent about an hour bleeding the coolant system. Yes I had the front of the car up in the air, the closed hood was at chest height on me. I got all the air out that I could and drove the car home, a very easy 12 miles. I then drove it back to the shop first thing this morning and went about my business. I should mention that I bled the system well enough that even at operating temp the upper radiator hose had plenty of give to it compared to the balloon about to burst feel that you get with air in the system.
At the end of the day I pulled the valve cover and did one last pass on the head studs with the Snap-On torque wrench and they were all at 90ft-lb. I then buttoned her back up and took her out for a good hard run with several pulls at full boost and WOT. The previous two 12 mile drives were kept under 3k rpm and in vacuum. After pushing her hard I checked the upper radiator hose and it was tight as in pressurized. I cracked open the bleeder screw and only a very little bit of air came out mixed with coolant. I then cracked open the top plug on the radiator and I got some air but as soon as I lifted the reservoir I got coolant. I did not feel any hiccups during the drive and I hope it is just a little bit of air that found it's way up when the engine/water pump turned at higher rpms. I then drove her home with a couple good pulls and the radiator hose seems to be appropriately pliable. Comments?

Secondly, I have noticed a big difference in the engine after redoing the head gasket and changing the oil to a thicker 20w-50. It seems to be turning much more freely even at start up the starter spins faster.

Also my boost is consistent. Before at full boost my gauge was reading 12-14 psi but my waste gate spring is a 0.8bar or just at 11.6psi. Now the boost gauge is reading a very consistent 11.5 every time I allow it to build.

The engine feels like it is more stable. I know that is a weird way to describe it but the engine feels smoother and once it gets out of warm up enrichment it wants to rev super fast.

Lastly I noticed that I am getting much more blow by coming out of the valve cover. The hose that used to return to the intake is now vented to the atmosphere and before the head gasket redo I may have gotten a little steam but not much else from it. Now I am getting what I would expect, hot oil steam and smoke but not smoke in a bad way (I don't think anyways).

I hope that it is fixed and holds up because I have an appointment with the dyno/tuner tomorrow evening and we will dial it in and see what kind of power she is making. And if all goes well we will turn the boost controller up to around 18psi. I am stoked.

IF YOU SEE ANY RED FLAGS IN MY OBSERVATIONS ABOVE PLEASE SPEAK UP NOW!!! I would rather postpone my dyno death day and drive her gently to the Vintage than blow her up on the dyno and not make the Vintage. OTIS? Jim?

[jim325]

A little blow by is expected. Highly unlickley u cracked a ring or piston causing excessive blow by with a mildly blown head gasket. You could always a quick(hahaahhaa) dry and wet compression test. More compression during a wet comp. test obviously worse than getting the same readings but not a huge deal unless the numbers a widely different wet/dry.

The fact that it runs better is likely a cause of the hg leaking since day 1 just didn't show up till positive pressure was achieved.

The engine builder that did my engine told me to follow BMW specs for head stud torque, he specifically said he knew more about domestic engines and not a lot about BMW's to give a reliable suggestion. Ur machinist thinks he knows everything, no offense to him or u, u should tell him what happened.

Did you get the head rechecked before u put the hg back on?

[RagtopE30]

No because I didn't over heat it severely.

[kamotors]

awesome build, also just a little advice from what I experienced, you need to ditch the spectre TB coupler. they will fail under hard driving(not street driving but things like auto-x)

problem is when they get hot and you boost they swell up, after repeated swelling they stay swelled and never fit again. I had spectre reducer and after a few auto-x's it turned a 3" coupler reducer into some crazy flared 4" balloon creature. Caused the charge pipe to pop off multiple times even with t-bolt clamps. Silicone couplers like turbonetics/mishimoto/treadstone are worlds better and around the same price.

[LJ851]

Lastly I noticed that I am getting much more blow by coming out of the valve cover. The hose that used to return to the intake is now vented to the atmosphere and before the head gasket redo I may have gotten a little steam but not much else from it. Now I am getting what I would expect, hot oil steam and smoke but not smoke in a bad way (I don't think anyways).



IF YOU SEE ANY RED FLAGS IN MY OBSERVATIONS ABOVE PLEASE SPEAK UP NOW!!!

If you mean vented to atmosphere literally and are not using an oil separator/catch can then you need to hook one up.

[RagtopE30]

^that is next on the list

[Good & Tight]

Matt, I would suggest routing the valve cover vent to the intake of the turbo.

IMO we would rather see the car than the dyno #'s this weekend.