The ups and downs of a 2.7L Turbo

[cleanasse30]

Shit that intercooler looks mean behind the grills :)

Good call on the drain line, Even a small low spot can do strange things. Out of curiosity, why vent your VC through the separator and then back in to your intake? Why not just vent to atmosphere?

Thanks! The catch can is routed back into the intake because I was/am having issues with burning oil during decel. I thought it was due to pressurizing the crank case initially so I was trying to pull vacuum with the intake, but I think that was a result of some other underlying issue...

this made me laugh in the office...LOLOL!

This build looks like so much fun! much respect! Would love to see the beast in person!

Thanks! I'm still working out some kinks but its a blast to drive! I'll bring it out to some local meets sooner or later lol.

[cleanasse30]

Copying these posts over from my other thread to get more visibility...

So I got back from my road trip last week. The engine still burns a considerable amount of oil, but from what my friends tell me when driving behind me it doesn't burn oil under boost. This got me thinking that maybe the m20 needs a constant vacuum source on the crank case. So I came up with an idea to achieve that by modifying my current oil catch can setup.

Here is a crude diagram:


Boomba Racing makes a 3/8" barb check valve which are the boxes inline in the diagram. This would allow the intake manifold to pull vacuum during cruising and decel, just like the stock system. When making boost, the valve inline to the manifold closes and the valve inline to the turbo inlet opens pulling vacuum during acceleration.

Post from last night:

So I ordered the boomba check valves and just finished installing them. As far as I can tell, its fixed and runs great! :) After a pull in the tunnels and watching to see if it dumped oil smoke during decel like it did before the install, the exhaust looks clean. I'm going to drive it to work tomorrow to to check the exhaust in daylight to double check.





Post from this morning:

Welp just got done driving it to work. I think the check valves helped, but it still poops oil smoke during decel in the higher rpms... Not as much as before, but definitely pooping oil smoke. I'm lost at this point. Don't know where to go from here...

HELP!?!?

[dugly52]

Great build. Love that the first thing you do is take it on a road trip. Inspiring for my build. Planning a turbo this winter, then want to take a road trip next summer. Glad to see in not the only crazy person who plans something like this.

[cleanasse30]

Great build. Love that the first thing you do is take it on a road trip. Inspiring for my build. Planning a turbo this winter, then want to take a road trip next summer. Glad to see in not the only crazy person who plans something like this.

Haha thanks! It sure was a test of my wrenching abilities, but other than the oil burning everything worked well and held up. The trip was amazing, I would def recommend doing a road trip! Just stay off the interstates as much as possible. The best driving roads are highways and back roads.

Biggest piece of advice I can give is keep your eye on the prize. Otherwise its too easy to get frustrated and lose motivation.

[ak-]

Bummed that your options didn't work out completely for you.

This seems to be a popular problem on m20's and I'd also like to find a solution.

[5Toes]

awesome project, sorry to hear about that issue, totally sucks especially on a trip

experiment with a few different oils.

awesome project. Just slapped a head on my b25 block so I was curious how you prepped yours. I ended up using a flat plane sander 16 inchs long with 320grit wet sandpaper.

[cleanasse30]

Bummed that your options didn't work out completely for you.

This seems to be a popular problem on m20's and I'd also like to find a solution.

Yeah same... I did some reading around and I believe the valve stems or seals were either not replaced by the head builder or he did a terrible job installing them. Burning oil during engine braking is a sign of pulling oil past the valve seals because of the vacuum that the engine creates when the throttle is closed. I believe the check valve system I made would work really well on a healthy head though since it acts like the stock system under vacuum, yet also incorporates a system to pull vacuum under boost. Might be worth giving it a try if you are having similar issues.

awesome project, sorry to hear about that issue, totally sucks especially on a trip

experiment with a few different oils.

awesome project. Just slapped a head on my b25 block so I was curious how you prepped yours. I ended up using a flat plane sander 16 inchs long with 320grit wet sandpaper.

Thanks! Yeah it was a bummer. I was sorta afraid of getting on it too much because of the oil burn issue, but it was still a great trip! We drove on some amazing roads and saw some absolutely beautiful scenery.

I think I'll try some 10W-40 in it when I change the oil soon. I'm just slightly worried about high oil pressures with a 40 weight oil though.

To prep my block I used a nylon abrasive wheel in a die grinder to clean off the old head gasket material and the carbon buildup on the piston tops. I was slightly worried about the the wheel messing with the sealing surfaces of the block but the engine has solid compression and the oil and coolant haven't mixed. Ultimately iron and aluminum are harder than nylon so it makes since that it worked.

[Northern]

I think I'll try some 10W-40 in it when I change the oil soon. I'm just slightly worried about high oil pressures with a 40 weight oil though.

Are you implying that you're running 30 weight now? why so thin?

[cleanasse30]

Yeah I'm running 5W-30 right now. Idk I guess I just defaulted to that as that's what I ran NA. It's due for an oil change so I'll try some synthetic 10W-40 next

[varg]

Nice build. Burning oil on decel like that sounds like valve stem seals to me.

[Northern]

I feel like a 50 weight oil would do you well (at least during the summer), although I get that 40 weight synthetics are much easier to come across.

[cleanasse30]

Scored some minty sport seats this weekend!



If I have time this week I'm going to switch to a 10W-40 oil and see how that goes. Thanks for the suggestions!

[cleanasse30]

I feel like a 50 weight oil would do you well (at least during the summer), although I get that 40 weight synthetics are much easier to come across.

So I guess I've never read the owners manual of the e30 since I bought it...

:stupidsign:

I didn't realize it calls for a 20W-50 basically year round where I live and I've been putting 5W-30 in it since I owned it I just ordered some Mobil 1 15W-50 synthetic which should get here today so I'll change the oil and see if that fixes the problem.

[BECKSTER]

Great build ! I bet driving her down the coast was a blast !

[Ether-D]

I have always had pretty great luck with conventional 15w-40 diesel oil. It has higher detergent content which is good for our old motors (when m20's were designed, all oils had higher detergent content I'm told).

Keep at it bro, looks great!