Piston Rings

[Guest coops222]

hiya guys...

i have removed and stripped my engine as it was smoking on acceleration.. a lot!!

 

how do i know if the piston rings are ok? can you tell by sight or should i just change any way?

 

(ive done the valve seals etc before i stripped the engine and it made no difference)

 

cheers paul

[biksz]

did you do a compression test to see if compression was down?

[Guest coops222]

yes, it was all normal , changed the head for an unleaded head and replaced valve seals.

that made me think it must be rings....

[Guest Adam Atchinson]

did u do a wet and a dry compression test ?

[Snapperpaul]

If compression was ok its not the rings although a leak down test may show a more accurate result

If you did re-ring then a light hone would be needed to bed the rings in

It may be that your sump was building pressure due to blow by past the valve seals this points to more than stem seals, could be worn guides.

 

A difficult diagnostic problem and rectification can cost more than buying another engine

[Guest coops222]

I have renewed the head and stem deals so it's unlikely to be anything to do

with head. It happened suddenly rather than gradually.

 

I will change the rings and see what happens. If that fails I have no idea

 

[Guest mower man]

If it happened suddenlyyou have to be looking for possibly broken oil contol rings [bottom one on thepiston ] a comp test would prob not reveal this especially if compression rings reasonable. Was there any loss of power or did it just start smoking ?,pull the pistons and clean ,check every thing hone the bore and re ring . HTH mower man

[Guest coops222]

That seems the most likely cause mower man. There was no loss of power. Can you see the damage if it is the ring? coz they all look fine... Also there did seem to be a lot of oil in the sump could to much oil be a cause?

Thanks paul

[Snapperpaul]

To much oil in the sump, and there would have to be enough for the crank to splash in to it, could defeat the oil scraper ring causing the engine to burn oil, this would only be untill the oil burned off.

If your symptom is under acceleration every time you floor the go p

[Pete Mar]

Did you check the engine oil breather? I know a badly blocked system can cause pressure build up in the sump and force oil up past the rings.

 

Just a thought.

[agent_zed]

how about a head gasket failure allowing high pressure oil to be pushed into the engine? not sure how close the oil pathways are or even if it is possible for oil to be forced into the cylinder or whether there is too much pressure for this to ever happen. just a thought.

 

I did once change a headgasket and something went wrong so that under higher speed oil was forced out of the block through the gasket and dropped down onto the exhaust causing a nice plume of smoke. The funny part was i went out to test it and drove down our local bypass just getting up to speed (and therefore revs) and the smoke plume started just as i rounded the corner to see police doing spot checks in the layby Police lady was worried it was going to explode or something. Left it 10 mins whilst i explained how i'd just done the gasket and then turned it on and it appeared fine as the exhaust had cooled and no oil was leaking at tickover so they let me go. Drove away slowly

[Guest zerorace]

Are you sure it was oil what colour was the smoke? white to light gray would point to head gasket dark gray oil

[Guest coops222]

it was oil, also there is thick black oil residue on the inside of the exhaust manifold..

[johnlrichardson]

If its a pinto it could be oil rings and still get good compression, when the pistons are out put a ring under the lip at the top of the bore and measure the gap and do the same at the bottom of the bore, if there is much difference get the bore measured it may need a rebore or you may be able to get oversize pistons.

 

HTH jon