Whilst having to remove the head from my S52 - I was cleaning it up for re-assembly and a noticed a pattern stain like an old water/rust mark on the #2 wall about 25% of the top of travel and 1" or so across.
I can feel it if I pass a finger over it but it is very light.
The car had good compression/leakdown in the cylinder before I yanked the head. It is a race-only motor.
Do I slap it back together and run it or start weeping gently into my hands at he forthcoming expense of new pistons/pins/bearings?
Dial bore gauge the cylinder and compare to recommended engine specs. If it's in spec scuff a crosshatch pattern w/ steel wool or wet/ dry paper w/ oil.
also be checking rings aren't stuck.
my cheap .02
I lightly sanded it across the bore with emory - placed the piston in the middle of the mark and filled the cylinder with pb blaster. It isn't leaking thru very quickly (almost all PB blaster still there after 30 minutes. I jogged it a little too.... and only trace amounts are visible below the piston from the bottom.
I am going to pretend I never saw it and re-assemble. If it makes thru the next three races I'll worry about a real solution over the winter.
To be honest from what you described I'd be concerned about a crack in that cylinder. You described what a friend saw in one of the cylinders of his Piper when a hairline crack developed.
If you were going to weep over pistons, pins and rings then you might need some tissues if that does turn out to be a crack. Are those block sleeve-able?
It warrants a pressure check.
Compression was good?
FIDO
It's a racecar, and they all break eventually.
The motor is a consumable item.
When is the next race, and how is your budget?
How many miles/laps/races/runs on this motor?
erohslc wrote:
When is the next race, and how is your budget?
How many miles/laps/races/runs on this motor?
2 weeks, E36 M3ty, all of last season and 1 race this season
If I have to rebuild... I'm done for the season. If it blows up, I'm done for the season.I'm going to say berkeley it and throw it back together and see what happens.
I'll just budget for a fresh 3.4L for net season 
GPS, do you race in CCA or another org?
Just asking as an LSx may be better for next season? 
vern2point3 wrote:
To be honest from what you described I'd be concerned about a crack in that cylinder. You described what a friend saw in one of the cylinders of his Piper when a hairline crack developed.
If you were going to weep over pistons, pins and rings then you might need some tissues if that does turn out to be a crack. Are those block sleeve-able?
What He said ^^^^^ Rust is a bad thing on a cylinder wall. I would inspect that very carefully as if it fails catastrophically you loose a lot more motor parts
Got Photos you can post up??
In reply to dean1484:
Il l post one later when I get home
Magnaflux it to check for a crack and put it together.
mbmsg
New Reader
7/15/12 7:42 p.m.
ok wally let me help you out. I'll give you 9k for that red thing in the garage. Just think of the motor you can build with 9k. I'll tell you what, make the air work in it and I'll bump it to 10.5 k that should give you a little extra for fuel and tires for the next race......
I could come get it Monday or Tuesday after work.. Will cash work or would you prefer a check?
MB
Make it 17.5 k and I'll even wash it before you get here.
mbmsg
New Reader
7/15/12 7:50 p.m.
your pb blaster post reminded me of the time my father in law asked me to look at his weedeater. It seemed the pull rope was locked or busted. I pull it apart, nothing wrong with rope. So i pull head to see whats up. piston wont move in bore, I spray a whole bunch of pb blaster around piston, check it every day its all there every day. nothing is leaking past after a week. So piston is seized, fused is probably a better description. So i give him the news, he says I quit putting all that oil in the gas, it smoked to much with all that oil in the gas do you think that had anything to do with it? I only hope my kids don't get his mechanical ability, I will be fixing things till the day I die.
Regardless good luck with wrenching it sounds like you will be cutting it close to be ready.
dean1484 wrote:
Got Photos you can post up??
It looks like damage from a previous head gasket failure where the coolant was dumping in from the water jacket port right above where the marks start. It isn't very deep - more like a discoloration with a very slight texture.
mbmsg wrote:
your pb blaster post reminded me of the time my father in law asked me to look at his weedeater. It seemed the pull rope was locked or busted. I pull it apart, nothing wrong with rope. So i pull head to see whats up. piston wont move in bore, I spray a whole bunch of pb blaster around piston, check it every day its all there every day. nothing is leaking past after a week. So piston is seized, fused is probably a better description. So i give him the news, he says I quit putting all that oil in the gas, it smoked to much with all that oil in the gas do you think that had anything to do with it? I only hope my kids don't get his mechanical ability, I will be fixing things till the day I die.
Regardless good luck with wrenching it sounds like you will be cutting it close to be ready.
Ha! Good story (saving all that nasty oil smoke is great for the environment ya know) - and yeah, I'm going to be rolling off the trailer at Summit Point with a patch job. That isn't anything new mind you - just that I've got two days where I am not traveling for work in the next two weeks to get it back together, in the hole and in the trailer.
If I finish well it will be awesome. If it blows to hell... it will be a good story on why you shouldn't ignore obvious problems with your motor and just slap it together in a big rush. Either way I get something :)
The photo looks like a head gasket failure. You should be good to run.
Your original description read more like a weep coming through the cylinder wall from the water jacket.
1988RedT2 wrote:
vern2point3 wrote:
The photo looks like a head gasket failure. You should be good to run.
My sentiments, exactly! 
I was more concerned with the texture eating the rings and losing compression than catastrophic failure - I emoryed the E36 M3 out of it last night and am really just waiting on a gasket set. It is going back together as is.
Giant Purple Snorklewacker wrote:
1988RedT2 wrote:
vern2point3 wrote:
The photo looks like a head gasket failure. You should be good to run.
My sentiments, exactly!
I was more concerned with the texture eating the rings and losing compression than catastrophic failure - I emoryed the E36 M3 out of it last night and am really just waiting on a gasket set. It is going back together as is.
I seen worse. Popping HG's on 302's with a little bit of boost, about 12-15psi, is fairly commonplace. Then if it wasn't HG's, it was split blocks and that made you just go get the nearest $300 motor and swap everything over to just do it again.
I doubt that texture will eat rings, remember that 2 stroke rings bridge some pretty wide gaps when they pass over the ports.
You have to bore a cylinder when you don't have any interesting things to say anymore.
