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Rod main bearing looking bad after 80H

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Rod main bearing looking bad after 80H

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Old 10-16-2012, 10:05 PM
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Originally Posted by supermx96 View Post
Before to looking at the worng place i have tear down the engine due to a melting piston by pre ignition on cylinder # 6.
I can not belive is that thing have make contamination in the oil, If anything happen the oil should be filtered before got the main and rod bearing.

I dont think that is the piston aluminum particule got into oil and make this.

What did you think?

dude you come on here asking about bearings then all the pros on here state their openion now you say you melted a piston????????????????
Its most likely from your rings or the ring carving at the cylinder wall....what a waste of peoples time and posts...
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Old 10-16-2012, 10:19 PM
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Originally Posted by mrfixxall View Post
dude you come on here asking about bearings then all the pros on here state their openion now you say you melted a piston????????????????
Its most likely from your rings or the ring carving at the cylinder wall....what a waste of peoples time and posts...
Dancing around the real problem.....
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Old 10-16-2012, 10:50 PM
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Originally Posted by mrfixxall View Post
dude you come on here asking about bearings then all the pros on here state their openion now you say you melted a piston????????????????
Its most likely from your rings or the ring carving at the cylinder wall....what a waste of peoples time and posts...
I cant imagine a melt piston can contaminated the oil pass trough the oil filter and do that on the bearing, i am not a profesional engine builder i build my engine by passion.

I realy think that is not the melt piston do that but as i said i am not an expert to know what is realy happened to the bearing.

I think oil heat and oil cavitation can do that
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Old 10-17-2012, 09:48 AM
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Originally Posted by supermx96 View Post
Before to looking at the worng place i have tear down the engine due to a melting piston by pre ignition on cylinder # 6.
I can not belive is that thing have make contamination in the oil, If anything happen the oil should be filtered before got the main and rod bearing.

I dont think that is the piston aluminum particule got into oil and make this.

What did you think?
I must say that melting the piston, will contaminate the oil! I feel we have been playing a guessing game here and wasting time. I don't care what you have for a oil filter, small micron or large, the small silica from the alum. burning away is going to most likely pass the filter or when the by-pass opened. Sorry to say; but I DO NOT SEE SCRATCHES IN THE BEARING, only embedded particles. Why did you melt the piston?
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Old 10-17-2012, 02:34 PM
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I am rebuilding an engine now with a burnt piston. I have some bearings that look just like that. The oil was sooty from combustion gas and the oil was rather over heated looking/smelling. That is what I attribute to the bearings that look like this.

Last edited by blue thunder; 10-17-2012 at 02:56 PM.
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Old 10-17-2012, 08:45 PM
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Originally Posted by MER Performance View Post
I must say that melting the piston, will contaminate the oil! I feel we have been playing a guessing game here and wasting time. I don't care what you have for a oil filter, small micron or large, the small silica from the alum. burning away is going to most likely pass the filter or when the by-pass opened. Sorry to say; but I DO NOT SEE SCRATCHES IN THE BEARING, only embedded particles. Why did you melt the piston?
I think i melt the no.6 piston due to a bad fuel distribution setup and during an engine test, the no. 8 have sufer also of pre ignition.
I ran 9 psi boost with b&m 250 blower with foward ofset carb plate, 7.5:1 comp ratio / performer rpm marine aluminim head i have run all the sumer long with a meth injection system with an afr between 10.5 to 11. During the fail test i run without met inj and my afr go up to 12.5 wot.
The piston # 5-7 no sing of pre ignition but much more leaner than the # 1-3 and the # 6-8 have sing of pre ignition (# 6 melt) also much more leaner than the # 2-4.

I have also fond a blown head gasket between #6 and 8 cylinder as i can see on the cylinder block.

Pic of the melt piston and better of the bearing:
Attached Thumbnails Rod main bearing looking bad after 80H-2012-10-17-21.16.00.jpg   Rod main bearing looking bad after 80H-2012-10-17-21.11.47.jpg   Rod main bearing looking bad after 80H-2012-10-17-21.11.07.jpg  

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Old 10-17-2012, 09:19 PM
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Originally Posted by supermx96 View Post
I think i melt the no.6 piston due to a bad fuel distribution setup and during an engine test, the no. 8 have sufer also of pre ignition.
I ran 9 psi boost with b&m 250 blower with foward ofset carb plate, 7.5:1 comp ratio / performer rpm marine aluminim head i have run all the sumer long with a meth injection system with an afr between 10.5 to 11. During the fail test i run without met inj and my afr go up to 12.5 wot.
The piston # 5-7 no sing of pre ignition but much more leaner than the # 1-3 and the # 6-8 have sing of pre ignition (# 6 melt) also much more leaner than the # 2-4.

I have also fond a blown head gasket between #6 and 8 cylinder as i can see on the cylinder block.

Pic of the melt piston and better of the bearing:
The second and third pictures are the Direct result of the first picture . Now you know what happened . Clean everything good before you rebuild and make sure she no sing of pre ignition no more .
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Old 10-17-2012, 09:38 PM
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Did you replace the oil cooler after the piston failure? If not, do so now.
Eddie
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Old 10-17-2012, 10:01 PM
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Originally Posted by Young Performance View Post
Did you replace the oil cooler after the piston failure? If not, do so now.
Eddie
Thanks for advice.
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Old 10-18-2012, 03:11 AM
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Originally Posted by supermx96 View Post
I think i melt the no.6 piston due to a bad fuel distribution setup and during an engine test, the no. 8 have sufer also of pre ignition.
I ran 9 psi boost with b&m 250 blower with foward ofset carb plate, 7.5:1 comp ratio / performer rpm marine aluminim head i have run all the sumer long with a meth injection system with an afr between 10.5 to 11. During the fail test i run without met inj and my afr go up to 12.5 wot.
The piston # 5-7 no sing of pre ignition but much more leaner than the # 1-3 and the # 6-8 have sing of pre ignition (# 6 melt) also much more leaner than the # 2-4.

I have also fond a blown head gasket between #6 and 8 cylinder as i can see on the cylinder block.

Pic of the melt piston and better of the bearing:
Do yourself a favor and get a set of je or srp piston's..the speed pro pistons your running dont have as good quality of alunimum as the je or srp pistons..
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