_blake

I have a 98 LS1+T56 going into my iroc.
(noob build)

I removed and painted the valve covers, I noticed some debris behind the rocker support bracket... so I took the bracket off and noticed more down some of the holes... so I took the whole head off. All the Rods+rockers seem to be in good shape, but the pistons look like crap and something looks to be growing on the otherwise smooth walls.

what should I do?

silverstreak98maro

iTrader: (7)

How many miles is on it and why did you tear down was it losing power or makin noises

_blake

It's a 98... I was told it has 73k on it.
Seems to be the 1st time it's been pulled apart.

It was never in the car at all, I took off the valve covers to paint them... but noticed some sand and dirt. It was behind the wall of the head as well (I could not reach), so I took the whole head off and found some rusty looking corrosion on the cylinder walls. Is this normal?

Darkman

iTrader: (2)

I don't see anything that indicates major damage. The carbon build up on the tops of the pistons is normal on a street driven car. You can run each pistion up to TDC and clean them if you like - brake cleaner and a scotchbrite pad works well for this. At least one of the cylinder bores has some rust that looks like the car sat undriven for awhile.

brianw401

iTrader: (4)

Just remember to wipe the cylinders down with fresh oil before you put the heads back on.

LS6427

iTrader: (2)

Yea man....just clean the pistons as well as knocking all that other crap off with sandpaper. Also, smooth out the deck with light sandpaper. Vacuum the crap out of the cylinders real good because some is bound to fall into them. Looks like burnt oil over years and years of driving on the pistons, thats all. Clean it off, it can cause detonation due to hot spots when the engine is hot under acceleration.

I had bad valve seals gum up my pistons something terrible with burnt oil....I was detonating like crazy because hot spots were pre-igniting my fuel/air mixture after I got up to operating temp. Cleaned them off while my heads were rebuilt and put it back together, and no more detonation at all.

.

01ssreda4

iTrader: (96)

Rust and carbon build up. Looks like the motor has sat for a while. Nothing a good cleaning shouldn't fix.

_blake

I got a good deal on these parts 1 year ago $1800
98 LS1/T56 + harness + PCM + pedals + LS1 tank + manifolds + mounts + radiator

it's been sitting in my garage up until now....

So I should clean the machined gasket surfaces and get the carbon off the piston tops (before it scrapes the walls). then after all that is done I should wipe the cylinder walls down with a bit of oil?

should I take the pistons out for this or can it be done while installed?
will sea foam or mineral sprites on a rag do the trick?

01ssreda4

iTrader: (96)

I always use brake parts cleaner or a scotchbrite roloc disc, just go easy. It helps to have the engine on a stand so you flip it over/blow it out. Try not to let any of that junk get wedged around the piston where it could scratch the cylinder wall.

_blake

here are a few pics of the project if your interested btw... spent so much time here that the engine got completely ignored.

some parts






engine bay

_blake

problem solved, thanx everyone
ordered bolts and gasket from summit.... while I was waiting a bit of cleaning was done.

I rotated the engine to get each piston TDC. The piston's head surface was cleaned, then ran over the whole thing with vacume, then wiped down the deepest cylinder wall. repeated this 4 times (for each rotation).



Driver side after cleaning


Pass side after cleaning


wiped down the walls with WD40, this is as clean as I could get them.

02ws.sik

looks good to me.

Darkman

iTrader: (2)

Looking good - keep some oil on those cylinder walls.

02ws.sik

what type of oil just like motor oil.

Darkman

iTrader: (2)

Yep - just a thin coat to prevent rust.

TImmy_Jones

iTrader: (4)

Please tell me you have a new bumpstick and a light port on the heads, while the engine is out and torn down.

01ssreda4

iTrader: (96)

Like the rear end, thats something you don't see everyday

Z28_Driver

Looks like a good engine. Still has the corss hatch in the cylinders. Might have had a small head gasket leak or that could just be from sitting. Either way you have enough sense to put new gaskets on so that should take care of the problem.
Great looking project by the way. Keep us posted on your progress.

_blake

called around to a few places to get my heads clean.. I was quoted $200 ($100ea) + 5 weeks from one place. a few other places said they don't work on aluminum, the last place said they wont do it. Unless I was getting more done the work was not worth the money

*******!!!

so I broke the heads down and did it myself. here are some before and afters for ya

made sure oven cleaner touched every wall and showed the combustion chamber some extra love.. YUK


then sprayed it everywhere, let it sit... then hit the gasket with a razor, then a GREY scotch bright pad.

_blake