I finished the tear down on Ol' Smokey. As I had stated before there was a knock that we had stethoscoped down to #1 and it was during the TDC of the stroke. Well, we were right. Holy piston slap bat man. Those of you complaining that you can hear a tick or knock from the passenger side (which is what I heard), pay attention to these pictures. BTW, I put down 434/970 with it this way, and it's put up with this for years. I haven't figured out yet what happened. The wrist pin looks to be good and so are the rod bearings. My guess is some sort of oiling issue, but we'll have to investigate further to see.

Passenger Side of Piston:


Drivers Side of Piston:

 

Thats ugly. Hope I dont have your luck, because I sure have the noise, just not on the passenger side, mine hides when I look for it, plus its only evident under load.

 

That damage is directly related to high EGT's - the piston expanded and tried to sieze in the bore.

Had the engine been of lower power, that would have siezed and locked.

You can see the baked oil stain between the top and second compression rings, where ring tension was failing after the first\successive overheating event allowing crankcase oil past the second ring, and combustion flame past the top ring.

Coulda been from flaky injector, and\or normal #1 specs, if the end bore-to-piston skirt clearance is greater than center pistons clearance.

Not good, at any rate.

 

yikes, how does the cylinder wall look? you gotta love the fact that they keep on rolling even when injured!

 

Alright here are the pics for what I am now calling "The Pit of Horror". I have a cylinder hone in my possession now and plan to attempt to clean the bore up, which either way I need to do to determine how far we need to go to clean this mess up. These shots are pre-honing, you can see the cross-hatching at the back of the bore and the lack of it on the sides. The walls aren't in as bad of shape as the piston itself, but my "warm and fuzzy" factor isn't there for being able to just hone this out.

So if I do end up having to bore it out and considering I'm running 435s from New Era, would it be advantageous to run a marine piston vs. a stock piston? I plan to run a marine gasket either 10 or 20 over. I'm already running a lot of timing to give me some upper end, it seems that it would make sense to keep that and take advantage of a larger bowl, plus lower compression allowing more boost. Opinions?

 

check it for "out of round"...

 

Like an egg...

 

After honing and honing, I think I have it now. Looks like I lucked out. There's only .005 difference between this cylinder and the others. He checked it out and gave me a clean bill of health!

 

Looks like luck was on your side, so to speak.
Do the cooling jets look ok?

 

I ran a small wire into the one just to make sure there was no blockage. I really wish there was a way to check them by running the oil pump and just watching to make sure they actually are squirting and making it to the cylinder wall. A plexi-glass oil pan with windshield wipers would sure be nice...

They "seem" ok.

 

You can check em , go buy yourself a bug sprayer , fill it with oil , and put 1/8 pipe plug fitting on the end of the hose, fit it to the pipe plug on the oil filter head, and hand pump it , check the flow. you can get as much as 30 psi from the hand pumping

 

OOOoooo, that is a good one and I already have a bug sprayer that I don't like. I do believe that will make for a good use of it. Great idea, thanks!

 

Glad to see you got it figured out. That first pic is just downright scary. It looks like in the first picture you were already prepared for the worst and started on your counterfit money ring!!!!

 

yeah, I was going to mention something about photocopying money...

 

How's that rod journal? Looks suspicious in the picture, but it could be the light from the flash, or just goop/debris.