FireballYoyo
FireballYoyo New Reader
8/9/17 1:59 a.m.

I'd don't want to relive my stupidity too much but I will take opinions.

A while ago while building my motor, my air nozzle dropped and nicked my block. I had to get it together for a trackday and it's been running strong for ~2,000 miles, but I wonder if this is an issue. Mainly that I could blow a headgasket in the future.

This is a turbo SR20 engine, and I'm mainly concerned with the nick on the chamfer of the cylinder. The other one is larger but I think pressure is the greatest at edge. It's hard to describe the depth, I could just barely feel it with a fingernail. My fear is that deterioration creeps through that outlet and leads to a failure.

Alas, my failure:

Thanks all, all input welcome.

tuna55
tuna55 MegaDork
8/9/17 8:25 a.m.

I am not an expert by any means, but that looks tiny.

APEowner
APEowner HalfDork
8/9/17 8:52 a.m.

That should be fine on anything other than a steel shim type head gasket and even then it's probably OK.

oldeskewltoy
oldeskewltoy UltraDork
8/9/17 8:55 a.m.

you should be fine

bentwrench
bentwrench Dork
8/9/17 10:03 a.m.

I know you have assembled the motor already, but for future reference...

Lay a gasket on the deck and see if the nick falls in an area that is critical.

Most gaskets dont seal that close to the edge of the cylinder. Even a metal shim.

pinchvalve
pinchvalve MegaDork
8/9/17 10:30 a.m.
bentwrench wrote: I know you have assembled the motor already, but for future reference... Lay a gasket on the deck and see if the nick falls in an area that is critical. Most gaskets dont seal that close to the edge of the cylinder. Even a metal shim.

WAIT, YOU NEED A GASKET ON A HEAD?!?!?!?

HonestSpeedShop
HonestSpeedShop New Reader
8/9/17 11:09 a.m.

I have had much worse and never had a failure.

BrokenYugo
BrokenYugo MegaDork
8/9/17 11:49 a.m.
bentwrench wrote: I know you have assembled the motor already, but for future reference... Lay a gasket on the deck and see if the nick falls in an area that is critical. Most gaskets dont seal that close to the edge of the cylinder. Even a metal shim.

This, look up the bore diameter of the gasket you used, most are oversize at least 1mm to allow for oversized pistons. Even if the fire ring does cover that nick I'd guess the ring is wider than the nick, has "flowed" into the nick to some extent (the head bolts put a lot of pressure on the gasket), and would have blown on the first track day if it were a problem.

FireballYoyo
FireballYoyo New Reader
8/9/17 11:03 p.m.

Thanks guys, makes me feel a lot better. The only thing my motor hypochondriac self goes to now is that the further away divot could be an air pocket that expands and contracts with every engine cycle, stressing that area of the gasket. At the same time, ideally the gasket can withstand that pressure.

What's the worse that can happen blowing a HG on track anyhow? Usually highest load is on a straight so hopefully just a breakdown and not an unknown off-track event.

Jere
Jere Dork
8/9/17 11:59 p.m.

Yeah no biggie, especially with coated gaskets or the oem graphite ones.

I have filled in worse with permatex copper gasket spray (which I spray headgaskets with anyway).

Our Preferred Partners
nB9cD4tAtqLNAtfdTSj3bZdSU3NnAvE2iNPtG5LA9bRC3tz7OHnSbaeeTrXroqvN