Smokey engine
Turbo Mini Forums

I have at last finished the rebuild and got it running with the GT17.

The head is from the old engine, so its not the valve guides. The bores were excellent and I just deglazed them before fitting some excellent pistons with new rings -maybe rings nor yet bedded in ?.

However, cylinder 3 and 4 show lots of oil on the plugs and its smoking like a bastard.

Could the turbo be passing oil from too high oil pressure ? (I have 80lbs + when cold and the turbo is just freshly rebuilt)

If the turbo is passing oil then why only the two cylinders ?

Getting quite down about this and thinking about refitting the old engine and T3

Whats the compression like Dave?

Could be the rings not bedded in yet like you say.

I don't think the garrett range like over 60psi going through them so you could try a restrictor? or as a quick test disconnect the oil feed for the turbo (you could probably do with propping the turbo so it doesn't spin)

If something is worth doing, it's worth doing half of.

If its running ok, I'd be tempted to put a few miles on it and see if it improves when the rings bed in.

Have you checked the pipework from the turbo to see if there is any oil present?

Edited by matty on 24th Mar, 2011.

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1/4mile in 13.2sec @ 111 terminal on 15psi

what about valve seals?

Done now needs redoing lol

He said the head is from his old non smokey engine so should be ok :)

If something is worth doing, it's worth doing half of.

let a bit of oil out to the low mark on the dipstick ? see what that does.
also try taking off the turbo to ic pipe ,and see if it has oil in it .

Edited by robert on 24th Mar, 2011.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Fair point robert. Is it breathing heavy Dave?

If something is worth doing, it's worth doing half of.

I have three breathers, presently waiting to be connected up to my Evacusump system, just left open to atmosphere, not even a catch tank, and they all are clear, no smoke or even vapour.I can feel the pulsing from the crankcase, so they are working.

Its only run for 20 minutes in the workshop, not been driven yet, so no conclusive evidence of oil in the intercooler pipework,but I really am so pissed off that I have vowed not to even look at it until sometime next week.I suspect oil is getting past the seal on the hot end of the turbo straight into the exhaust.

All your suggestions are noted and will be acted upon - I have just received from Moss their adjustable oil pressure relief valve so will fit that and lower the pressure a bit. Roberts did suggest this to me on the old engine along time ago.
Maybe lower oil pressure will mean less leakage too.Recent thread on oil restrictors for turbos got me thinking a bit too.

Thanks to all for their interest and suggestions.

Report later - maybe.

Chin up old bean.

Thanks Tom, but its not the first engine I have ever built and none previously have smoked like this on startup.

I take on board what you and the others are telling me, but I think I will cover the countryside in smoke. Maybe I should nip out on Sunday morning early while everyone is still in bed after the clock change ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I reckon that it's the oil pressure being too high and pushing it past the turbo seals.

Usually the inline engines sit with the flywheel lower. So the oil is running towards the rear inlet and into cylinders 3 & 4.

Park it nose down and see if it oils 1 & 2 to confirm.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I too would say oil being pushed past the turbo seals - the compressor side will dump a little bit on the pistons (and I agree with Paul's logic why mostly 3 and 4) and the exhaust side shaft seal will create the masses of blue smoke.

My engine - garage testing only as it has been for the last year :( - did exactly the same once, and once only, last year. 20 minutes into a test run and 3 minutes of blue smoke then back to clear, as it has been ever since. Never did find out why, just assumed it was the turbo exhaust seal ring sticking temporarily, they are pretty basic.

How is your turbo drain routed now you're on a GT series, is it possible the drain is resticted and back-pressurising the seal rings ??

Try dumping the drain straight into a plastic bottle just for a short test to see what the total turbo oil flow is. I did this when I first built mine just to make sure there was enough oil flow.

Schrödinger's cat - so which one am I ???

The GT17 seems to be a bit touchy when it comes to the oil drain. Matty found this out, and it was chucking oil out the compressor. Matty changed the oil drain and it stopped passing oil over.

Yeah they really don't like even the smallest of restrictions in the oil return.

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1/4mile in 13.2sec @ 111 terminal on 15psi

a lot of the faliures on them seem to be coking related to to exess oil in the exh housing, this in turn shags the bearings in them.

This is all really helpful, thanks everyone.

I had already thought of jacking the car up at the back and running it - the engine is installed with a slight rearward lean but its nice to have confirmation of my thought.

The oil drain drops straight down from the core and then uses the MT silicone elbow and the original fitting on the side if the block, turning through a right angle as it does so - should be OK ?.

Rods experience encourages me to persist ( I have had some oil for a while on startup with previous builds, but it normally clears after 10 mins or so.

Got to spend most of the weekend with my youngest son and his wife, who are visting with the brand new (5 weeks old) baby girl, so I might be in a better frame of mind by next week.

Lots to think about and put into practice.

I,m under time pressure as I have a commitment to appear in Dundee in May and Amsterdam two weeks later, as well as the usual club functions, where I am expected to be in an Austin.

Just noticed the kisses from Robert - he will bear watching, methinks ?

Made me smile anyway, Robert.