. How can you tell if the shinny ends are from the initial file fit or from butting? This is getting stranger by the hour!
Never a Good Thing
- Thread starter Ishiftem
- Start date
Maybe you could gap the second ring a little more , gas may be being trapped between the top and second ring causing ring flutter as Russ mentioned.
I have been basing my answers on common sense knowledge. This is getting past my pay grade. I think it's time to go through the piston, ring and cylinder bore and ask, what is different about this setup than others.
Since we know that the rings transfer heat fron the piston to the cylinder walls and if they don't you will have more heat in the piston and rings can we ask why the rings may not be making reasonable contact with the cylinder. What oil are you using for the Dyno pulls?
If the rings are butting ????it is not from flutter or pressure To butt..the rings would have to grow in length. That could only be a product of heat. I would guess that since aluminum expands more than carbon steel... the heat required to expand the rings would cause the pistons to drag the cylinder walls. Don't see how the rings could be butting without the heat showing elsewhere
Yep, have to go to the basics here. Very interesting problem. I'm tapped out. 
Is the ring groove to deep in the piston?
What changed? I think you had lots of runs when you tore it down a couple of years ago. You rebuilt it and if I remember correctly you had Piston problems. Maybe not. You've probably been through everything in your trouble shooting, but maybe run through it all in print for the guys that know something.
The rings are butting for sure. If you look closely at the pictures, you can see the darker grey area where the rings were ground and not touching verses where they are shiny and polished from touching. In person under magnification, it is very clear where the ends were rubbing and have a polished appearance and have polished most of the marks from grinding off. The bores looked like shit. I didn't take pictures of those before I had it honed. Yes it puzzling. My engine guy who has seen the parts is scratching his head also and he is no slouch. Just this weekend he is at Beach Bend tuning two cars he did engines for that Qualified #1 and #3 in mx235. Both cars in the final have his engines. I'm going to look over the plugs again.
Dave I did have problems before. Bad piston rock and butting rings. Rings were gapped at .028. Sent total seal pictures of the rings and they said they were butting for sure and to open them up to .034 which is what I did this time. This time also have different pistons that cured the rocking, or I should say cured it as much as possible given the lopsided and top heavy nature of the design.
Dave I did have problems before. Bad piston rock and butting rings. Rings were gapped at .028. Sent total seal pictures of the rings and they said they were butting for sure and to open them up to .034 which is what I did this time. This time also have different pistons that cured the rocking, or I should say cured it as much as possible given the lopsided and top heavy nature of the design.
Look into "Line to line " coating to help with piston rock. I use it.
I have heard good things but I'm tapped out!!!!!
Rings only. Only a couple light marks on the piston but that's to be expected given the material that came off the walls. This is an n/a engine no nitrous.
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