330BHP Rebuilt Engine Smoking on Overrun

[Andy Cotton]

Chaps - I need some urgent help.

I've got a BAM engine in my Elise and I have just had the engine rebuilt with the following :-

New Scat Rods
RE-Hone
New Piston Rings
New Big Ends
New Mains
New Oil Pump
Crank Polish
New Crank Seals

20 new Valves
Refreshed head
New Valve guide oil seals

The head work was done by 1st Head rebuild in Telford for £350.

I have done about 350miles so far and the car is smoking on the overrun but only really around town. The turbo I bought brand new a yr ago and has covered 15K. I put a turbo pre filter on the oil line before I started it up and it's a Garett GT28RS - the turbo was fine before the rebuild. The engine is BAM code.

Everything I have read points to valve guide oil seals but these are supposed to be brand new but I am not too sure if they used genuine bits (I'll ring them tomorrow to find out). If it is this, does the head have to come off or is there anyone who can do it in situ ?

The oil I am using is cheapo for the first 600 miles but saying that it is still fully synthetic.

HELP HELP HELP

 

[m0rk]

it's be worth having a look on the inside of the intercooler hosing to make sure that it's not oily so you can rule out the turbo seals

in a 'normal' car you just whip the head off to do valve seals, I can't remember if you've got the room in the elise to do that

 

[traumapat]

my valve guide oil seals went. car was fine unless left idling for a minuite or so then youd get a puff of smoke on pulling away. otherwise no smoke.

had head done and now theres no smoke at all.

are you losing oil?

 

[DPJ]

There should be a restrictor in the oil line to the GT28RS.... have you got one?

 

[Backdraft]

Rebuilt engine

Hi Andy,

I would start with a compression test.

If you have oil in the turbo system this may be due to increased oil pressure after the rebuild. We can do you a restrictor that goes in the oil feed to the turbo. We are fitting them to all our turbo kits now.

Let me know if you need anything.

Best Regards
Mark
Backdraft Motorsport
01908 821216

 

[h17och]

i wouldnt reccomend running cheap oil ever. some good quality running-in oil is best.

as for stem seals, they may not have protected them from valve stem when inserting them!?

HoocH

 

[ibizacupra]

The oil I am using is cheapo for the first 600 miles but saying that it is still fully synthetic.

bores? were honed?

dont use any synth oil for running in... Woops.
how many miles you done on it so far?

 

[m0rk]

says about 350 miles since rebuild.

would be a major problem if you've lost oil in that time(measurably)

 

[Andy Cotton]

Chaps,

More info - the cars covered 550miles now and I got somebody else to drive it so I could observe.
Basically - no smoke during normal and heavy accel and deceleration i.e from about 3,000 rpm to 6,000 rpm........absolutely zilch - even reving it to 5,500 and letting off (zero throttle position) there is no smoke.
Now get the car doing 2300 rpm to 1500 rpm (with zero throttle) and the car smokes which is basically around town.
As for the restrictor I belive it's in the turbo (maybe not) but it was fine on the old engine and nothing has changed appart from an oil filter being put in line.

I guess I am losing oil as there is blue smoke - but I'll let the car settle before I measure it.

My thoughts now are Turbo ?????

 

[Backdraft]

Oil restrictor

Hi Andy,

Needs a restrictor.

Best Regards
Mark
Backdraft Motorsport.
01908 821216

 

[Andy Cotton]

No sorry - I don't get it . Why has it done 15,000 miles without one and it never smoked.

Now it needs one, and why all of a sudden are you recommending one. Why didn't you tell me this when you sold it to me ?

Anyone else ?

 

[Backdraft]

Just trying to help!

Hi Andy,

As you said you haven't had a problem for 15000 miles! You have rebuilt the engine and I imagine the oil pressure is now in top condition. Wouldn't recomend using cheap oil though.

We have had a couple out of 30 odd turbo kit installs smoke. Oil restrictors have cleared the problem instantly. Garret have now recomended oil restrictors on all their ball bearing range. So we now fit restrictors on all our kits.

Hope that answers your concerns.

Best Regards
Mark
Backdraft Motorsport
01908 821216

 

[Andy Cotton]

Bill - why don't you run an engine in using fully synthetic oil ?

Can you explain please. What would you recommend for running in (a bit late for me now though) and what would you recommend in general. I usuaually use Mobil 1 and change it every 2-3K.

Andy

 

[ibizacupra]

Bill - why don't you run an engine in using fully synthetic oil ?

Can you explain please. What would you recommend for running in (a bit late for me now though) and what would you recommend in general. I usuaually use Mobil 1 and change it every 2-3K.

Andy

Because its TOO GOOD AN OIL... the running in process is bedding in the rings to bores etc........... too good an oil and you just glaze the rings/bores, and poor oil consumption/compression can the occur.

Its basic 101 engine running in... and on the dont do list.
regular plain jane multigrade and change it after the run in period.

I run 15W50 V300 Motul oil in mine.. 100% sheer stable oil, double ester based lubricant.
I have previously killed mobil 1 on a turbo car, so avoid it these days myself. too thin.

 

[ibizacupra]

maybe of help for next time Andy

http://www.elitedubs.com/index.php/topic,2635.0/topicseen.html

Bobq builds some excellent engines and is one guy I would listen to

 

[cupra_matt]

Yeah defo need a restrictor, Any blower with ball bearings needs one, Journal bearings dont.

 

[Andy Cotton]

I spoke to a Company called Turbo Dynamics today and they recommend a restrictor only if the pressure is over 45psi, otherwise you can damage it if there is less pressure.

So the way forward for me is :- measure the oil Pressure, I have an oil restrictor coming tomorrow. Change oil for another 400 miles or so just while I finish the run in period (closing the stable door after the horse has bolted I know) and then put the V300 in.

See what happens - I'll keep you posted.

 

[ibizacupra]

Yeah defo need a restrictor, Any blower with ball bearings needs one, Journal bearings dont.

this is the thing I have'nt nailed down yet..... Owen Developments said not to add another as the dual BB has a restrictor in its top already.

most advise over on vortex says to add a restrictor tho...

 

[tashacupra]

Can anybody confirm that this restrictor is defo required on ALL makes of turbos with ball/roller bearings, or is it just garrett family/ garrett hybrid? i'm now fiting an IHI vf searies turbo which is ball bearing but done a serch and not found much on anybody having any problems with IHI?

 

[HTC]

IHI VF doesn't require a restrictor.

Andy, so you are basically only getting oil consumption issues under high vacuum?

Most of the piston ring bedding in is done the first time you drive the car. Synthetic is too slippery for this process. You run mineral oil and then get rid of it after a a few miles. I wouldn't run synthetic until you done a fair few thousand miles.