Smoke at high revs.

[Dub-Se7en]

ever since the trackday i have had problems with blue smoke at high revs, was thinking it was the turbo but now i'm not so sure cos if i hold the car @ 5000 rpm in neutral so it's not building boost i'm getting a fair amount of blue smoke, i'm thinking maybe i've goosed the rings

will try the old stock turbo but that's not in great shape either :homer:

thoughts?

 

[glanzanut]

id agree@maybe rings mate
compression test would be the way to go:freddy:

 

[Dub-Se7en]

aye, good plan. leakdown test too.

may whack a stock turbo to it too to rule the hybrid out.

 

[sx_turbo]

you have pm ian.

 

[GTnomez]

i think it may not be the rings although a comp test would say different.

reason is that i think i have done one of my rings in due to an aweful misfire, i do get smoke on idle and when stopped at traffic lights but i always thought that it was my turbo.

eliminating the turbo would be a goo start and doing a compression test but im too scared to do that incase of the result!

 

[Idrees]

PCV valve??

 

[Dub-Se7en]

i get no smoke that i can see on idle, but sometimes get an oily smell which i attribute to it breathing heavily. i'm pretty sure i know what's up with it now....

 

[madmanGT]

track days are very hard on cars man,i wouldnt be surprised if it isnt a cracked ringland on the piston or rings anyway..do the compression test anyway it will give you a better idea..baffeled sumps is wat we all need...

 

[Rory]

Have you lost any performance that you can feel, or does it still pull just aswell?

Compression test should rulle this out or not.

I would be tempted to replace the turbo first, or whip the down pipe off to see if there is any oil in the exhaust side of thing.

Make sure you dont have an oil leak anywhere that drips onto the exhaust. Just to rule that out.

As for baffled sumps, you dont need them that much, if you dont track your car that often.
Ive done 7 trackdays, and my engine is still strong

 

[Dub-Se7en]

no performance loss that i can tell, although since it's been smoking i've been driving real easy not only for reliability but cos it's going through oil like a mofo on hard boost. drive normally and the car is fine.

will do a compression test later i think

 

[madmanGT]

Have you lost any performance that you can feel, or does it still pull just aswell?

Compression test should rulle this out or not.

I would be tempted to replace the turbo first, or whip the down pipe off to see if there is any oil in the exhaust side of thing.

Make sure you dont have an oil leak anywhere that drips onto the exhaust. Just to rule that out.

As for baffled sumps, you dont need them that much, if you dont track your car that often.
Ive done 7 trackdays, and my engine is still strong

you wernt going hard enough then no but when going hard into corners ect an oil going to 1 side can be bad for the engine, plus not mention all the high reving round the track..it just couldnt be good for the engine..so haven a baffled sump would realy help,an i am deff looking into 1..but as the rest of the guys said,check ur turbo first! and compression test an go from there.

 

[GTdan]

same probems as mine ian, but on comp/leak down test - all was fine, so i ve just bought a forged engine, will only find out whats wrong when its stripped down - but either valve stems or rings....

 

[weakboy2]

You say it breathes heavily Ian??

If so then it points to rings

 

[TurboDave]

Cracked ringland even a hairline crack could cause this and I'dd say is more likely than a ring.

 

[Dub-Se7en]

most likely, the compression test doesn't make it obvious though.

1 140
2 145
3 139
4 140

bear in mind we built this engine to be low comp, lots of chamber work and a 1.4mm headgasket.

tested it again holding the revs and no smoke at all, strange. when i get chance will swap turbos and see how things go, really not wanting the rebuild again at the moment.

 

[Monkfish]

Any ideas on the cause Ian? The Bitch is leaking oil and smoking at an alarming rate. I have a feeling either she's shat an oil ring or a blockage in an oil line is causing increased pressures.

 

[Dub-Se7en]

never been happy with the piston to bore clearance, even though the cylinders are an exact 74.5mm, just felt too loose for a new engine. so think most of the problems are down to that.

 

[sx_turbo]

Any ideas on the cause Ian? The Bitch is leaking oil and smoking at an alarming rate. I have a feeling either she's shat an oil ring or a blockage in an oil line is causing increased pressures.

what happened to selling it?

and chances are its ringland damage, best doing a compression test, and check all other possible means first i.e turbo etc etc

 

[weakboy2]

Thats ross pistons for you though!

 

[TurboDave]

most likely, the compression test doesn't make it obvious though.

1 140
2 145
3 139
4 140

bear in mind we built this engine to be low comp, lots of chamber work and a 1.4mm headgasket.

tested it again holding the revs and no smoke at all, strange. when i get chance will swap turbos and see how things go, really not wanting the rebuild again at the moment.

This is where the ringland phenonimum begins :freddy:they are a nightmare to pin down unless they are totally cracked.

How it works is as the rings move around the piston bit by bit when the small gaps in the rings meet the crack in the ringland they allow some oil through and cause intermittant smoking, however forged pistons shouldnt have cracked could be down to clearances as you say but it then should be more stable oil burning/smoking.