Cylinder FRP Gouge - Salvageable?
#3
Depends on how much you value your reliability. I have delt with nicked cylinders before. Being that its nicked horizontally and not vertically is a plus. But it looks deep? hard to tell from the picture. If it were me, I would hone it to knock down any edges or use what you can and run it. Getting rid of any edges would be a must. It will either A: be fine (albeit, burn a little more oil) or B: cause a hot spot and eventually cause too much PTW or ring clearance and you'll loose compression on that cylinder...assuming FRM doesn't delaminate like Nikasil does
Last edited by Charper732; 08-19-2018 at 04:35 PM.
#4
#5
Seems like maybe I can get some more life out of it.
The gouge seems pretty deep, maybe 10-20 mils at the center and it's about 3/4" long. Do you suggest just a local honing of the high spots, or the full cylinder? If just locally, I assume I would still need to pull the block?
The gouge seems pretty deep, maybe 10-20 mils at the center and it's about 3/4" long. Do you suggest just a local honing of the high spots, or the full cylinder? If just locally, I assume I would still need to pull the block?
again, Im not there so don't know how it feels. As back-woods as it sounds, some very fine sand paper and careful maneuvering could get the edges down without making the cylinder out of round.
#6
What have you got to lose? You can either run it, and see what happens, in which worst case is it dies and you need a new engine, or you just get the new engine without even trying.
So why not try?
I would do the redneck thing suggested and knock away any high spots as carefully as possible by hand with sand paper. Sand sideways, not up and down. Use very fine sandpaper. Only sand the high spots, not the cylinder itself. This isn't bodywork sanding to blend imperfections, its just making sure ring doesn't catch on anything. So you don't want paper to touch any of the surrounding material, just those high spots.
One advantage this has over honing is you aren't touching the rest of the bore, just this one damaged spot.
Obviously this engine isn't going to last as long as if thus never happened. The question is simply, how long will it last. That may end up being a very long time.
So why not try?
I would do the redneck thing suggested and knock away any high spots as carefully as possible by hand with sand paper. Sand sideways, not up and down. Use very fine sandpaper. Only sand the high spots, not the cylinder itself. This isn't bodywork sanding to blend imperfections, its just making sure ring doesn't catch on anything. So you don't want paper to touch any of the surrounding material, just those high spots.
One advantage this has over honing is you aren't touching the rest of the bore, just this one damaged spot.
Obviously this engine isn't going to last as long as if thus never happened. The question is simply, how long will it last. That may end up being a very long time.
#7
Thanks. I think I'll give it a try. I think I have some 1000 grit and 3000 grit wet sandpaper. I'll lubricate it with some ATF and just go for the high spots. Initially and along the way I plan to check for high spots with a precision straight edge and feeler gauges.
Any thoughts on how to prevent or remove debris from the cylinder?
Any thoughts on how to prevent or remove debris from the cylinder?
Last edited by Charper732; 08-20-2018 at 12:44 PM.
Trending Topics
The following users liked this post:
Slowcrash_101 (08-21-2018)
#10
What a bummer. We have all done things like this. I know I have anyway. I hope it works for you. I bet it works out fine.
I have not changed the retainers in either of my ap1s. I inspected them, and they are not cracked. I was convinced by comments that Billman made in these pages that unless the tell-tale signs of cracking are observable on careful inspection, the ap1 retainers are fine and the thing to do is to leave the retainers alone. When you buy an ap1, I think the first thing to do is to pull the cover and do a valve adjustment. While you are in there, inspect the retainers carefully. If they are ok, button it up and enjoy the car. The only thing that causes the retainers to crack is a mechanical over-rev. If you are the only one driving the car you will know if you have mechanically over rev'd the engine and you can open it up again and inspect for cracked retainers. If they are cracked replace them. If not, leave them alone. The ap1 retainer issue is something that leads to burned valves over a long period of time operating with cracked retainers that can result in the valves not closing properly which prevents the valve from dissipating heat properly into the head at the valve seat. Sudden catastrophic failure caused by healthy ap1 retainers is not the concern. If that was the concern, then yes, I would be in favor of replacing them as preventative maintenance. If you have a massive over-rev you will have catastrophic failure no matter whether you have ap1 or ap2 retainers. In my humble opinion, this ap1 retainer thing falls squarely in the old adage: "if it ain't broke, don't fiix it." Others see it differently, I understand. But, that's my take. The key is careful inspection.
I have not changed the retainers in either of my ap1s. I inspected them, and they are not cracked. I was convinced by comments that Billman made in these pages that unless the tell-tale signs of cracking are observable on careful inspection, the ap1 retainers are fine and the thing to do is to leave the retainers alone. When you buy an ap1, I think the first thing to do is to pull the cover and do a valve adjustment. While you are in there, inspect the retainers carefully. If they are ok, button it up and enjoy the car. The only thing that causes the retainers to crack is a mechanical over-rev. If you are the only one driving the car you will know if you have mechanically over rev'd the engine and you can open it up again and inspect for cracked retainers. If they are cracked replace them. If not, leave them alone. The ap1 retainer issue is something that leads to burned valves over a long period of time operating with cracked retainers that can result in the valves not closing properly which prevents the valve from dissipating heat properly into the head at the valve seat. Sudden catastrophic failure caused by healthy ap1 retainers is not the concern. If that was the concern, then yes, I would be in favor of replacing them as preventative maintenance. If you have a massive over-rev you will have catastrophic failure no matter whether you have ap1 or ap2 retainers. In my humble opinion, this ap1 retainer thing falls squarely in the old adage: "if it ain't broke, don't fiix it." Others see it differently, I understand. But, that's my take. The key is careful inspection.