Engine rebuild querys

[sx_turbo]

ring lands on the 4e engines are extremely weak, they dont like high heat and dett.

ideally to re-use that block you need to go for oversize pistons and rings,

as for the other engine, until you strip it down you wont know if broken ringlands have caused damage to that bore also. and dont just use a good piston from the other engine as they are numbered to each bore, and so most likely you will need to order a new piston from toyota, luckily there not wallet emptying expensive.

also looks lite the previous engine failed to very poor mapping

 

[WallaceGlanza]

You're probably right on the poor mapping, when I took it to wallace performance just for a rolling road run it was pretty lean (after having been mapped years before at a different place).

The other engine was still running fine except breathing heavy and chucking out oil so I'm hoping there is no bore damage - there was no horrible noises anyway! Will find out soon though.

It's only 3 sizes of pistons isn't it? So I'm hoping I'll be able to make one good and correctly sized set out of the two engines.

 

[Skalabala]

No its not. The piston has CHUNKS out of it, not chipping

Detonation can deform the look of a piston in many ways. That is detonation for sure bud
Scroll down on this thread.
Example

 

[Skalabala]

You're probably right on the poor mapping, when I took it to wallace performance just for a rolling road run it was pretty lean (after having been mapped years before at a different place).

The other engine was still running fine except breathing heavy and chucking out oil so I'm hoping there is no bore damage - there was no horrible noises anyway! Will find out soon though.

It's only 3 sizes of pistons isn't it? So I'm hoping I'll be able to make one good and correctly sized set out of the two engines.

When it comes to worn out sleeve and piston then it will not be the end of the world to swap mk2 with mk3 pistons.
Those running clearances are long gone and not applicable any more when bores looks like yours.
And for sure they are oval.
I will put my luck on the engine that recently failed because the block usually survives broken ring lands when not driven for a long time.

If you can find a reputable brand 1st gen 5efe 74.5mm piston set then you can use it as is(you have a tunable management?) or you can turn the crown down to 29.8mm compression height.
Good for 200hp. Ring you go with Hastings, Rikin, NPR, Goetze etc

However the max piston to wall clearance spec for this engine is very high I would not recommend to go close to it.
You want 40-50 micron for a reliable engine.

I would also have the injectors tested properly

 

[sx_turbo]

It's only 3 sizes of pistons isn't it? So I'm hoping I'll be able to make one good and correctly sized set out of the two engines.

yeah only 3 sizes

 

[WallaceGlanza]

When it comes to worn out sleeve and piston then it will not be the end of the world to swap mk2 with mk3 pistons.
Those running clearances are long gone and not applicable any more when bores looks like yours.
And for sure they are oval.
I will put my luck on the engine that recently failed because the block usually survives broken ring lands when not driven for a long time.

If you can find a reputable brand 1st gen 5efe 74.5mm piston set then you can use it as is(you have a tunable management?) or you can turn the crown down to 29.8mm compression height.
Good for 200hp. Ring you go with Hastings, Rikin, NPR, Goetze etc

However the max piston to wall clearance spec for this engine is very high I would not recommend to go close to it.
You want 40-50 micron for a reliable engine.

I would also have the injectors tested properly

Yeah I'm running an emanage blue (and new injectors now) but this engine/block is gonna be put back in a corner until I decide if I want to forge it, so it will be bored out for that. Although the corrosion is fairly deep so I may need to go up to 75mm pistons but we'll see when it comes to it! Once the next engine is rebuilt if will definitely be straight on to a rolling road to check the fuelling.

So onto the next engine.....

I'm quite happy with this one, no problem with the bores and no det marks, it looks a good bit richer running than the other:









I was actually starting to wonder if there was anything wrong with this engine until the tell tale signs were spotted...



And with the rings off...



Exactly the same as the one out the last engine, both from cylinder no 4 as well:



The engine otherwise looks good so I'll hopefully get it back together soon, I've got the correct piston to go in place of the damaged one then it will get new rings (and a hone of the bores), bearings, head gasket and valve stem seals.... then I'll give it some abuse on track

I've got plenty bits to choose from now!