Do I need to be concerned?

[BARRACUDA1968]

Some of you may have followed a previous thread about my head gasket issue on my new stroker build.

I'll be installing TA heads before the motor goes back in but I noticed all my cylinders have these markings.

They correspond to the top and bottom of the piston on the cylinder wall. The cylinder wall is still smooth so I wasn't sure if after a 1000 miles if this is something normal during break in or I'm heading for a disaster.

The specs you see in the picture are from the graphite head gasket and the distortion you see on the piston is just the picture.

I can't remember but I think my pistons had that coating on them? That may be what's causing these marks? Dunno?

I never had any real KR and I never milk shaked the motor. I only had a small compromise in the head gasket between cylinder 3 and 5. Nothing on the passenger side so I don't think this has anything to do with coolant in the cylinders. My head gasket issue never got that far.

What are your thoughts?

 

[thadeal4real]

Too tight or got hot

 

[BARRACUDA1968]

Never got hot so it must be tight.

What should I do from here?

 

[TurboBuRick]

What cylinder is that? Just the one or do others look similar?

 

[BARRACUDA1968]

That is #5 and it's the worst but yes all cylinders have it to some degree.

 

[1952ray]

That is #5 and it's the worst but yes all cylinders have it to some degree.

If it were me I would call Dave, also I would pm Earl and Nick to see what they have to say

 

[BARRACUDA1968]

I kind of thought those guys would happen past this thread sooner or later.

If not I'll get ahold of them.

 

[thadeal4real]

if it were me I would just hone it out for a fresh set of rings and put a fresh set of rings on it and then it should be fine just my 2 cents

 

[BARRACUDA1968]

I'm hoping that's the case. I'm .030 over now and don't want to go .040 and have to buy new pistons.

 

[m233roller]

Might be a hair tight but hell they all do it on the thrust side of the bore. Give it a light hone job, throw new rings in and GO !!.
You definitely DON"T need to bore it and get new pistons.

 

[hiboom]

I've seen that on several of my engine I thought it was from the piston rocking in the cylinder do to the short skirt on the piston and Riss pin location but I'm a body man and painter by trade so don't take my word I'm might be totally off lol

 

[bison]

Measure the bores and measure the pistons. Then measure the ring end gaps. Otherwise I wouldn't do anything. Throwing rings in won't correct it


BPE2013@hotmail.com

 

[whitehot1]

Looking at the picture and was thinking,thats kind of dangerous for me.lol

My question has nothing to do with your question about the cylinders. But more for the head gasket failure in the other thread and it may have been answered there and i just may have missed it,please forgive me if i did.

But just curious did you or anyone measure/check the dowl/head alignment pins to see if they weren't raised to far out of the block and keeping the heads from being able to seat/seal properly?

 

[BEATAV8]

looks normal to me....
As Bison said. Measure to be sure.

Wasn't smoking and burning oil judging by the looks of things. Probably fine.

 

[earlbrown]

Can you feel the scratches with your fingernail? Sometimes pictures can make things look much worse than they really are.

 

[Mike T]

I put a borescope in my cylinders at 1k and it had small marks on the walls but very similar to yours. The compression was very good and it did not use oil so I figured it was ok. My guess was that small pieces of carbon from the top of the piston was riding on the top ring causing the marks.

 

[BARRACUDA1968]

I did check the dowel pins and all was good from the other thread.

The bore feels smooth, I can't feel any scratches with my finger nail. The picture is cylinder #5, it is the worst and then #3. I compromised the gasket at the water port between those cylinders. I know when I did it too. It was after about 900 miles of break in. I have an HD actuator so 18 psi is as low as I go. I had made several 10 psi to 15 psi short pulls using my foot to control boost. No KR to this point and AFR looked good enough to put my foot to the floor so I did on a long stretch of highway. When I let up and looked in the mirror I had a trail of smoke following me an 1/8 mile long. I had no KR and AFR was 10.0 to 10.2. My guess is I lifted the head and sucked in coolant? I stopped 2 miles down the road in a town and looked things over and everything looked ok? It never did that again? At any rate shortly after that I had creamy valve covers and PCV system and the other thread explains the rest. I guess I just lifted the head enough to compromise the head gasket but not blow it to milkshake the motor.

For those who didn't read the other thread my new motor had too much compression and I didn't know it. My tune was not sufficient.

I'll have to decide if I want to tear it down or not. Like Earl said pictures always look worse. Probably a good idea to have someone who knows more than me take a look while it's on the stand just for piece of mind. If it comes apart things will be measured.

Thanks for the posts!

 

[earlbrown]

If you can't feel it with your fingernail, those scratches are probably just cosmetic.

That being said, if you don't know your piston-to-cylinder clearances, you're still kinda blind.

 

[BARRACUDA1968]

True.