Blue smoke on a cold start. Forged pistons

[GreddyMR2]

Yes, I will order rev3 gasket. I know sump needs to be removed.
But do you think its possible to do this work with engine in car?

By the way, my dad talked with some engine mechanic and he told that these blocks don't like to be tightened up strongly (it was tightened according to ARP).

[bobhatton]

Yes, I will order rev3 gasket. I know sump needs to be removed.
But do you think its possible to do this work with engine in car?

By the way, my dad talked with some engine mechanic and he told that these blocks don't like to be tightened up strongly (it was tightened according to ARP).

It is just down to how easy you think it will be removing the head with the engine still in the car.

The head studs need to be all as per the ARP spec.

[GreddyMR2]

Things are getting worse.
My dad wanted to drive a car to mechanic, started, it threw lots of smoke and after couple of mins it started work like on 1 cylinder with lots of smoke and died.
What could be that???

[synXero]

How long was it sitting unused?

[GreddyMR2]

Overnight or something.

[MR2 Rich]

It could be loads of things. Why don't you get the mechanic that built your engine to have a look at it as the work he has done might be linked to your problem?

[bobhatton]

It could be loads of things. Why don't you get the mechanic that built your engine to have a look at it as the work he has done might be linked to your problem?

It is but he got it wrong the first time, why would he get it right the second time?

[MR2 Rich]

What do you think it is then Bob?

[bobhatton]

Well it is going to be the rings for sure.
We also had problems when not using Toyota valve seals.
And if the bearings are worn on the turbo then the seals on that may well leak oil.

It could be all three.

Take the turbo and head off, you should soon see any oil and where it is coming from

[GreddyMR2]

We have a diagnosis.

Turbo unbolted - looks fine.
Head is off - rings are gone... Ring gaps are about 3mm. But there were good gaps when they were fitted so how could they wear so fast?

One more question. Can I buy original metal head gasket when my pistons are 86.5mm?

[bobhatton]

We have a diagnosis.

Turbo unbolted - looks fine.
Head is off - rings are gone... Gaps are about 3mm between cylinder and ring. But there were good gaps when they were fitted so how could they wear so fast?

One more question. Can I buy original metal head gasket when my pistons are 86.5mm?

Ring gaps are between ring ends not ring to cylinders.

What is the piston to bore clearance?
Measure the bores and then the pistons.

[GreddyMR2]

Ahh, my mistake about the gaps.

My engine builder told that everything is fine (pistons and cylinders), just the rings are dead.

[GreddyMR2]

Today I visited my engine builder.
All is going quite well, I should get the car back next weekend.

He advised me to use a good oil even on brake-in, because the oil I've used now could have caused a bit of damage on bearings... There were some very small signs on bearings.

Regarding piston - cylinder clearance - it's about 0.09mm. The other guy said me recommended gap for wisecos is 0.07mm, so here we have even bigger.

You can see here old ring fitted in a cylinder with about 2.5mm gap. New rings have almost no gap at all.

[bobhatton]

Today I visited my engine builder.
All is going quite well, I should get the car back next weekend.

He advised me to use a good oil even on brake-in, because the oil I've used now could have caused a bit of damage on bearings... There were some very small signs on bearings.

Regarding piston - cylinder clearance - it's about 0.09mm. The other guy said me recommended gap for wisecos is 0.07mm, so here we have even bigger.

You can see here old ring fitted in a cylinder with about 2.5mm gap. New rings have almost no gap at all.
Image Replaced With URL For Quote http://i.imgur.com/RtRk499.jpg

If the piston to bore clearance is 0.09 and it should be 0.07 then the block has been bored to large, it will have some piston knock when cold and will have more blow by.

The block has to now be honed to be able to run the rings in.

The ring gap has to be set correct, not too small and not too big, it has to be right.

You need to use running in oil, mineral oil, not synthetic or semi synthetic as it is too slippery and the rings will not bed in.

It looks to me like there are detonation marks on piston no.4.

[MR2 Rich]

Signs of detonation? I hope he has checked his compression ration, don't you Bob?

[GreddyMR2]

It's not my detonation signs, they were when I bought the pistons.

Can you explain what is blow by?
I didn't notice excesive knocking sound.

[takman]

It's not my detonation signs, they were when I bought the pistons.

Can you explain what is blow by?
I didn't notice excesive knocking sound.

blow by is combustion gases in the cylinder getting past the piston rings, and getting into the crankcase.

Some amount is normal...too much can create problems.

[bobhatton]

It's not my detonation signs, they were when I bought the pistons.

Can you explain what is blow by?
I didn't notice excesive knocking sound.

They are there because I think your pistons are 9.0:1 if I remenber right, only good for low boost or high octane fuel.

Blow by is the air and fuel that gets by the pistons down into the sump then comes out the cam breather hoses. Theses should not be plumbed back to the turbo inlet, they should breath out below the gear box.

[GreddyMR2]

Thanks for explanation.

I will boost no more than 1bar on ct20 turbo. Should I be worried?

[MR2 Rich]

You will be fine Greddy, Bob "The Compression Ratio" Hatton will say different, but you will be fine.