RicerSchnitzzle

Just got the heads of my daughters 4.5L and found a little damage to the very top of the cylinder wall. There are scratches on top of the cylinder and the bottom of the head. I found what was left of a very small washer. Who knows how long it was in there. Anyway the cylinder wall damage is very small and only at the very top above where the rings would travel. It is only at the very edge where the head gasket seals. Old head gasket was fine.
Question: If I carefully smooth out the less than .5mm section should I be okey with a new head gasket?

Thanks.

marton

Foto?? If it is above where the rings travel then why worry about it? Maybe a foto would make your worries clearer?

Marton

88porsche928

if you have the money
http://www.928motorsports.com/services/uschrome.html

mark kibort

If the engine is out of the car, buy my 4.7 euro new engine!

If not, and to answer the question, it should be ok, if its not anwhere near the top of the cylinder. (the mating surface. depending how deep it is, sanding it down would or could make things worse as far as that is how the head gasket seals.) post a picture for the forum to evaluate.
if it is just in the cylinder walls, expeciallly if it is in the "dead zone" where the rings never touch and carbon builds up, it should be fine.

based on the description, its hard to tell. pics can help here.

Here is scots 4.7 before we welded this up and decked the top. then i grenaded, and we bore it to 100mm. this block has been through the ringer!
However, it is running great now in scots 5 liter racer
Mk

88porsche928

has any one attempted to hot weld scratches and cracks in the cylinders?

toofast928

Best approch is to have the head shaved at a machine shop. .002 maybe? Then the valves could be cut with new valve seals.

What can you do about the cylinder? Nothing, compression is good right then leave it alone. The other approch is to venture on a $5,000 rebuild.
Tony

michael j wright

When I tore down my 4.5 it had a broken ring and some scratches on the cyln wall about mid way down. I never did anything to it except knock the high spots of with a small hone stone- not what I preffered doing, but from what I had read about the reconditiong of these cylinders thought that even if it failed would be better(cheaper) at that time to just go for it. the car has been running fine with no smoke or oil burning problems for two years now- so I would say -go for it!

RicerSchnitzzle

I'm heading back to the garage to do some more work tonight, I'll get a pick. The damage is on the very top inside edge of the cylinder wall. Basicall if you run your finger around the edge you can feel it and it you run your finger across the top of the cynlder where the head gasket seals you can feel it. All of the damage is actually inside (Just barely) where the head gasket ring fits.

Here's where it is using Mark's photo. Again less than 1/2 a mm notch of material missing. Should be real easy to make smooth.

RicerSchnitzzle

Okay here's a pic of the damage to the top cylinder wall and piston top. I smoothed out the damed on the cylinder wall and will get the piston top later tonight.

Notice the damage is above the piston ring travel area and is also inside the head gasket sealing ring.

I'm thinking I'll be okay. Cycling the engine by hand is smooth with evident scraping in the cylinder. That washer may have been in there for a long time.

dr bob

Not possible, unfortunately. The Reynolds alloy in the block/bores is impregnated with silicon, something you couldn't duplicate with weld material. Of course there's the bore distortion that's inevitable with a weld repair. So it would need to be rebored, honed with paste to leave the silicon slightly proud of the aluminum, and new pistons fitted. A used 4.5l engine is often cheaper than a bearing and gasket set, or the cost of machining the block, or a set of pistons and rngs new. The value of the cars in the market right now causes many cars to go to the parts pile when there's a serious bottom-end engine mechanical problem.

largecar379

T-P,

if you need a set of pistons/rings, see the PM I sent you.

thanks---Russ

Fabio421

You could lightly polish it with a dremel to keep it from being a hot spot. Other than that its not going to effect much.

mark kibort

It doesnt look that bad, which is amazing if there was a washer in there!
Knocking that down a bit so it isnt a hot spot , is probaby going to work, but i would be worried about other damage, but i guess if there isnt any, you are ok.

mk

RicerSchnitzzle

It was running when torn down. Her timing belt showed signs of wear so I figured lets do everything all at once and your good to go for a couple years. I no idea I would find what I did. I smoothed out the piston top last night as well as the cylinder damage. Buttoned it back up. Cams back on this morning. Just need the intake and axhaust reconnected and we shall see what happens.

Thanks for the advice guys.

Daniel Dudley

I lost a washer in a Fiat engine once. Man was it ugly ! I smoothed the top of the piston and the head and all was fine. It was far beyond what you might imagine, with a piece of broken washer sticking out of the head. That engine ran great for years.