Author Topic: Cylinder/Ring Wear Issue  (Read 4361 times)

Offline msundstrom

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Cylinder/Ring Wear Issue
« on: October 23, 2017, 03:16:09 PM »
What is causing the etching at the top of the cylinder and the small scratches? Are they related? This is a 505 BBC on 45% Nitro. After 3 passes cylinder leakage was 8%, after 17 passes it ranged from 14% to 28% with no oil on the plugs but down on power. All eight cylinders/pistons and rings look the same and the top ring is very worn but the second looks great. The ring ends have not been butting and there is no signs of detonation on the piston, spark plugs nor the top rod bearings.
Thanks
Mark S

Offline masracingtd1167

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Re: Cylinder/Ring Wear Issue
« Reply #1 on: October 24, 2017, 09:36:01 AM »
It looks like too much fuel to me ! You can do just as much damage to a motor from being too rich ! This is a piston from my sons car with too rich on a ntrous tune up 

Offline msundstrom

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Re: Cylinder/Ring Wear Issue
« Reply #2 on: October 24, 2017, 11:19:01 AM »
Is it washing the oil off the piston and walls?

Offline masracingtd1167

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Re: Cylinder/Ring Wear Issue
« Reply #3 on: October 24, 2017, 12:27:36 PM »
It sure looks like it to me ! I should also add that we were also having a problem with a piston that was not properly built for what we were doing !I would highly recommend that you box your worst piston up and send it to Bill Miller . We did this with a Ross piston and Bill Miller himself called my son and explained that the Ross piston was not a bad piston but is just not right for his combination ! Miller built him a new set of pistons and some suggestions and they work great ! My son is now going mid 6.50's at 209 with a 572 big block with 2 nitrous kits and no piston issues !

Offline Frontenginedragsters

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Re: Cylinder/Ring Wear Issue
« Reply #4 on: October 24, 2017, 06:33:34 PM »
msundstrom:
 Injected nitro?
How much compression ratio?
Driving a Front Engine Dragster builds character and keeps you awake for a 1/4 mile at a time.
http://www.pro-formancespecialties.com/

Offline msundstrom

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Re: Cylinder/Ring Wear Issue
« Reply #5 on: October 25, 2017, 12:01:51 PM »
Yes, injected nitro and 12.23:1 compression

Offline BK

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Re: Cylinder/Ring Wear Issue
« Reply #6 on: October 25, 2017, 01:13:00 PM »
Could the ring issues be from the piston cocking in the bore like it does?

Offline THE FRENCHTOWN FLYER

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Re: Cylinder/Ring Wear Issue
« Reply #7 on: October 28, 2017, 09:00:01 AM »
My thoughts too. Above the top ring land is usually several thousandths smaller in diameter than the skirt and for it to be contacting the wall so heavily I wonder if you have too much bore clearance, exacerbated by an unfavorable L/R ratio?