engine cyl walls / rust question

[TajMan]

Ok, it happens for various reasons, water can get into engines and water on unprotected steel = rust.

I recently pulled my old Stealth SOHC engine apart that Jordan still owned, he had left it sitting in the dirt uncovered and rain could go right into the lower intake manifold.

Rust was BAD. Some work to scrape cyl walls and get pistons out the top, my goal was to salvage possibly pistons but mainly rods and crankshaft.



I recently also pulled the head off my Talon to fix, it overheated bad warping the head a few months ago and has just been sitting that way.

Well, I guess from driving the car just a few more times at the end, and from topping off plain water in cooling system to keep it going for a few more miles.... coolant in engine was mostly water alone and of course some of it pooled on top of pistons as car just sat... THIS caused rust.

Not to the point of having to dis-assemble the bottom end again I believe, but requires some good cleanup now and requires oil/filter changed quickly a couple times after I get it running again.

My question, after I carefully scrape surface rust from cyl walls, what is the best sandpaper to hit those rust spots with lightly?
1,000 grit or 1,500 grit or emery cloth?

[BaadVR4]

I have a set of new, in the box, .020" oversize pistons for a 3.5l SOHC engine. $175 shipped in US. LMK.

[KeithMac]

Best off bying a honeing tool you can fit in a drill and hone them out. Worth the investment.

Also depends how pitted the cylinder walls are after you`ve cleaned them up.

[Chris@Rvengeperformance]

yeah I was going to say honing tool as well, but holy shit that looks rough. may need a bore

[green-lantern]

may need a bore

This is what I'm thinking.

[TajMan]

THAT PIC IS NOT THE ENGINE I'M FIXING
if you read my story...

One engine is a Montero 6G72 SOHC V6, pic is of my old Stealth engine that had bad damage (but the rods and crankshaft were fine).

Cyl walls with real light surface rust in some spots, I'll be cleaning up, is on my Talon 4G63T engine.

NOT taking pistons out the bottom-end, probably not buying a hone, probably use some 1,500 paper I have here very lightly in a couple spots..

[BaadVR4]

Not a problem. My pistons are for a 6G74 engine anyway.
As for cleaning up the cylinder walls without piston removal, it isn't the best way to proceed. It is all but impossible to keep the sanding debris from getting behind the piston rings. Even with 2500 grit paper, there will still be significant dirt/dust/debris generated. With the piston still installed, that all has to go somewhere. It can easily act as a cutting medium and ruin the cylinder wall and the rings/pistons. If you are able to get all the trash out of the cylinder, most of it will wind up in the oil pan. From there it can wipe out the crankshaft/bearings. Good luck with the repairs. Just my 1.5 cents worth.

THAT PIC IS NOT THE ENGINE I'M FIXING
if you read my story...

One engine is a Montero 6G72 SOHC V6, pic is of my old Stealth engine that had bad damage (but the rods and crankshaft were fine).

Cyl walls with real light surface rust in some spots, I'll be cleaning up, is on my Talon 4G63T engine.

NOT taking pistons out the bottom-end, probably not buying a hone, probably use some 1,500 paper I have here very lightly in a couple spots..

[Chris@Rvengeperformance]

THAT PIC IS NOT THE ENGINE I'M FIXING
if you read my story...

One engine is a Montero 6G72 SOHC V6, pic is of my old Stealth engine that had bad damage (but the rods and crankshaft were fine).

Cyl walls with real light surface rust in some spots, I'll be cleaning up, is on my Talon 4G63T engine.

NOT taking pistons out the bottom-end, probably not buying a hone, probably use some 1,500 paper I have here very lightly in a couple spots..

'
Jesus Taj, there is no need to be a dick, sorry I couldn't read your mind. I was only trying to help.

[TajMan]

hey hey not trying to be a dick, just wanted people to understand the real story, everyone jumping on the bandwagon of 'oh that pic is bad, you need a hone'

I appreciate advice and suggestions.
I'm considering things from a few sides, and my Talon is NOT that bad...

[BaadVR4]

hey hey not trying to be a dick, just wanted people to understand the real story, everyone jumping on the bandwagon of 'oh that pic is bad, you need a hone'

I appreciate advice and suggestions.
I'm considering things from a few sides, and my Talon is NOT that bad...

Not to beat a dead horse..............but I've been doing this for right at 50 years...........and people think they can polish a rod or main journal with the crank in the car, put a new bearing in and all will be fine..........or that they can remove metal from a cylinder wall without removing the piston and all will be fine. Maybe you can, maybe you can't. But I've never done either successfully, nor have I ever seen anyone else do either successfully. On the other hand, I've seen probably 50-100 attempts at one or the other that turned a rebuildable engine into a boat anchor. And I've never been sorry I took the time to do it right the first time. Again, just my 1.5 cents worth.