Rediculous oil consumption
Turbo Mini Forums

1380 N/A engine

Right, the 1380 i've got in my mini at the moment is costing me more in oil than in petrol! Arg. Basically i'm using about 3 litres a week.

A bit of background on the motor...

The bottom end had a rebuild about 4000 miles ago with new rings etc. The head is a SRE race head but with unknown mileage. All breathers are vented to atmousphere. The motor doesn't leak oil.

It smokes like an absolute trooper apart from when you're cruising at very light throttle.

I have done a compression test and am getting readings of about 15 bar at WOT, does this rule the rings out?

I also noticed that the head is not fitted with stem seals on the valves, would it actually make it that bad?

Compression test will tell you nothing - a cylinder leakage test is where its at!

On 5th Sep, 2011 Vegard said:
I stand corrected. You should know

I'd try putting some stem seals on first.

In the 13's at last!.. Just

you really would hav eto go some to loose 3 litres of oil down the valve stems in a week,

but it is possible, i had an All agro that used a gallon a week,
it did not really show bad signs of oil consumption out of the exhaust but if i let it over run for more than 5 seconds the whole world dissapeared in a cloud of smoke on reapplication of the loud pedal, my engine was sucking some serious oil down the stems,
try the overrun trick and see what the signs are out the back,

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

What oil are you using Owen? I recently switched over to fully mineral 20W50 and the mini is drinking it down like a good un so i'm re-introducing semi-synthetic oil, as the engine never used a drop before.

well if it smokes that bad on all but prtial throttle then a complete rebuild with new block looks on the cards

always looking for them bigger bunches of bannanas

I seriously doubt its stem seals as Owen says it doesn't smoke on light throttle.

It would be rings and / or bores. The A series is not spectacular in regards of ring to bore sealing and when you go to these bigger bores, the bores actually flex quite a bit which doesn't help.

A ring(s) may have broken (detonation?) and / or poor breaking in would also do it.

are the plugs covered in oil? it may also be worth popping the head off to have a look and check the gap between the rings and bore. pure some oil into the bore and see what happens

Carl, I'm using 20/50 mineral atm.

I took the plugs out, they aren't oily, but are covered in carbon also, the electrodes appear to have almost disintergrated on all 4 plugs :S .

I have to whip the head off now as the head gasket has just gone urg.


On another note, the engine never smoked until this head was put on it.

Edited by Brett on 31st May, 2010.

Yes i moved to the darkside

Instagram @jdm_brett

I hope it's not det, i've been running with the dizzy slightly retarded until she goes on the rollers (again). It's also overfuelling massively.


The head has 19cc chambers and the pistons iirc have 9cc dish. I think it's around the 12.5:1 mark.


P.s. I didn't build this motor, it is out of my mates car so you can't go telling me i've put the wrong bits on it LOL.

Edited by Brett on 31st May, 2010.

Yes i moved to the darkside

Instagram @jdm_brett

Well I pulled the head today...


The HG was gone big time between 2 and 3.

Also there is a LOT of slap in all 4 pistons, and the cross hatchings on the bores are non existant...(considering this was rebuilt 4000 miles ago and not has not been hammered this doesn't seem too good???)

Also, I found 2 broken inner valve springs, and 2 bent pushrods.


So i've decided to change it for a 998. Seems a bit 2 steps back, but I'm not going to replace the rings as it's not my engine.

My engine also smoked excessively whilst overfuelling and has virtually stopped now that its set up properly-bore wash is the term, I believe ?

Mind you, it leaks more than its ever burned !