524td to 2.7L turbo project

[ISO_524td]

I guess I'll be going the route of "turbodan" with the details of why in this post:
http://www.mye28.com/viewtopic.php?p=236556#236556

Being in CA and using a smog exempt 524td, I can have some fun with this. I have a 1983 2.7L eta engine with 214K miles that runs great. I will rebuild 1st though using the 325i head, MLS gasket, upgraded bearing shells and turbo pistons. I will utilize all of the existing turbo hardware in my 524td including the exhaust manifold, turbo, crank, IC and external wastegate.

I've read over many posts and have a good feel where I want to go here. Is there anything else anybody here would recommend?

Thanks,
Chris H.

PS. I've learned alot my 524td project and will try once more before giving it up.......

[turbodan]

Its a shame that your m21 is toast. But, I think you will be very happy with the 2.7l gasoline turbo engine. Depending on how much work you want to do on the manifold, you might consider using an e cam and intake. Especially so if you're going to use the stock td turbo, with the 50 trim compressor and .36 A/R turbine. To bolt that on as is it would work best with a whole 2.7e motor, intake and all. The stock td wastegate will do about 10 psi, which would require some ignition timing retard to avoid serious detonation.

One advantage of the 325i head is the combustion chamber design. I've had much better luck with the "885" style chambers than the eta style chambers as far as detonation resistance. Perhaps the ideal setup would be with a super e engine with the 885 head and matching 2.7e pistons with an e cam. Looking at my dyno chart, I really think this manifold would make better power with the e trimmings. And the torque would be positively nasty.

Given the availability of T3 parts, you could swap out the diesel turbo for a 60 trim compressor, .63 A/R turbine, or a .48 A/R for an e engine, and a more appropriate wastegate. To make the most of this configuration, you would likely need to do some port work on the manifold itself. A good starting point for boost would be 6 psi.

[ISO_524td]

Yeah, I noticed the stock eta motor detonates rather easily and that was a concern I had for this project. I think the "885" cylinder head will be a part of my build-up. The M21 turbo manifold will still bolt up to this cylinder head with the typical grinding that is required, right?

I have 60 trim T3 compressor upgrade out of a turbo Ford that I was going to use for this as well. Any good recommendations for lower compression pistons or will the stockers be just fine?

Thanks for the help!
Chris H.

[Flip_Side_the_Pint]

The M21 turbo manifold will still bolt up to this cylinder head with the typical grinding that is required, right?

I
Thanks for the help!
Chris H.

Right, you'll have to notch the m21 manifold to fit the m20 head. You can do this easily by taking a stock m20 exhaust manifold gasket lining it up with the m21 manifold. Then making some according marks then notch away.

[turbodan]

I had best results with the 885 style head in conjunction with the 325i/super e pistons. You would probably be alright just bolting it onto standard e pistons though. The super e pistons make for an 8.8 to 1 CR, which is a little high for a turbo.

The manifold will need the lower studs notched out and you should work on the ports and runners as well. I took a load of metal out of the inside of my td manifold. I should have taken more, judging by the torque curve. Just keep casting thickness in mind and you'll be alright. A good shortcut for the notching is to only work on cylinders 2-6. You cant get a nut on the #1 exhaust stud, so just pull the stud and save yourself some work. I ended up pulling three studs on mine. #1, #2 and #5. No leaks, no problems.

[T_C_D]

It's nice to see some useful information being posted!