If you are racing it makes all the difference in the world but how many of us are out there killing it on the track?
Progress Thread Komo's 1990 GT - Parts Gathering Purgatory & Home Remodel
- Thread starter gkomo
- Start date
DadLife0724
Active Member
I am sure it does. I'm more worried about what the guy next to me at the red light in the camaro thinks before I blow his doors off.
In reality i should probably be saving my money up for an engine rebuild, not buying suspension parts.
Got to use my new swiveling borescope today to check out my problem child #7 cylinder. If you recall, the entire combustion chamber was covered in black carbon/sludge, from the piston top to the upper combustion chamber and valves. I see MAJOR improvement with the piston top and piston edges, but not so much the upper area of the combustion chamber and valves:
Edit: didn't notice it on the borescope camera screen, but picture #2 looks like i have some scoring on my cylinder wall there. Blah
@Noobz347 does this reinforce your thought that it was the valve stem seals leaking? Or not conclusive just based on these photos? Or does the scoring on the cylinder wall indicate a stuck ring? Or maybe all of the above!
Here's the post that shows how they used to look:
Edit: didn't notice it on the borescope camera screen, but picture #2 looks like i have some scoring on my cylinder wall there. Blah
@Noobz347 does this reinforce your thought that it was the valve stem seals leaking? Or not conclusive just based on these photos? Or does the scoring on the cylinder wall indicate a stuck ring? Or maybe all of the above!
Here's the post that shows how they used to look:
Started changing my spark plugs. Pulled out the first one and wanted to test my cheap borescope. This was the drivers side front spark plugs (easiest to get to):
Spark plug shows a little bit of oil on the threads:
And top of the piston:
Maybe this piston just happened to be at the top of the stroke because I couldn’t angle the camera to get a full good view. Definitely looks crusty.
Edit: second cylinder inwards with a side view camera angle showing what I’m assuming is the bottom of a valve and the top of the piston. Also crusty.
Edit #2...
Spark plug shows a little bit of oil on the threads:
And top of the piston:
Maybe this piston just happened to be at the top of the stroke because I couldn’t angle the camera to get a full good view. Definitely looks crusty.
Edit: second cylinder inwards with a side view camera angle showing what I’m assuming is the bottom of a valve and the top of the piston. Also crusty.
Edit #2...
Last edited:
DadLife0724
Active Member
Could that scoring be from something that was came off of the piston after you used additive?
The horizontal lines on the cylinder wall looks like cross hatch. Nothing wrong there.
The piston looks good but I don't see anything there that would indicate where the oil came from.
The piston looks good but I don't see anything there that would indicate where the oil came from.
Yeah, those don't look as good.
A couple of things come to mind:
One or more of your rings are not rotating.
If that is true, it could be the source of oil in the cylinder too.
My take? Pull the piston, clean the bore, and replace the rings. I will qualify this however, by saying that I would hit up some more of these engine guys before pulling the trigger.
A couple of things come to mind:
One or more of your rings are not rotating.
If that is true, it could be the source of oil in the cylinder too.
My take? Pull the piston, clean the bore, and replace the rings. I will qualify this however, by saying that I would hit up some more of these engine guys before pulling the trigger.
Too bad you can't use the 'fingernail tool' to gauge damage.
Can you scope the backside of the valves on that cylinder?
Can you scope the backside of the valves on that cylinder?
I can try next time I have some time. Kinda like secretly out in the parking lot doing this at work. Who knew work would be my only free time of the day.
Worse case is that you pull the motor out and tear it down to just re-ring (use a ball hone) and put new bearings in it with a new oil pump. You can check the heads by flipping them upside down and fill the combustion chamber with gas one at a time and look for valve leaks. Fix any leaks and have the valve seals replaced. Put the motor back together and seal it up.
Two things here, if there is no major damage then you just bought yourself some more time with the stocker but if it has bigger problems then you are at a cross road.
Two things here, if there is no major damage then you just bought yourself some more time with the stocker but if it has bigger problems then you are at a cross road.
No need to hassle with the E7 heads as I have the TFS 170’s ready to go. I don’t mind spending the money on supporting parts (for the heads) while I’m in there. I’m more worried about having to shell out for major shortblock parts/work.
I already have a new oil pump and some misc engine parts but a lot more would be required ‘while I’m in there’
I did a little more digging and phoned a friend. After that discussion I think DadLife is probably right. Something came off maybe a chunk of carbon buildup.
My theory would include some other signs.
Aerocoupe's recommendation still applies:
My theory would include some other signs.
Aerocoupe's recommendation still applies:
I’m feeling a little better about this then, pending an actual tear down to see what’s really going on.
The next big question is to cam or not cam if it comes to tearing down the engine.
Assuming to remove the engine, tear it down and inspect and replace wear parts as necessary at a MINIMUM would be $2500? Then add parts to support the heads and all the peripherals like timing chain and all that. This is probably looking like a $5000 job.
The next big question is to cam or not cam if it comes to tearing down the engine.
Assuming to remove the engine, tear it down and inspect and replace wear parts as necessary at a MINIMUM would be $2500? Then add parts to support the heads and all the peripherals like timing chain and all that. This is probably looking like a $5000 job.
You are in Cali and not trying to squeeze every last HP out of the engine and you're adding boost.
I'd keep the stock cam.
It is emissions legal and will still have the best street manners. I know that there are emissions legal cams out there but... How much of an improvement are they and at what cost?
Good to hear. I actually wanted to keep the stock cam but didn’t know if it would be dumb not to swap it if everything is apart. I just need like power from 1500-5000 rpm anyways.You are in Cali and not trying to squeeze every last HP out of the engine and you're adding boost.
I'd keep the stock cam.
DadLife0724
Active Member
Yea, and an aftermarket cam would probly give you cancer. 
Only effects rats in California, no humans were harmed during testing.Yea, and an aftermarket cam would probly give you cancer.
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