Question on built 6.0 that blew up
#1
Question on built 6.0 that blew up
Just built a 6.0 this winter got it in the car and put 500 miles on it put it on the dyno for 8 pull and then drag race it for 4 passes and on the 5 pass blew it up got it home pulled the motor apart and found number 7 and 8 piston gone broken rod in number 7 and number 3 piston was cracked all the way around what would of cause this ? Was turning the motor to 6500
#6
IMO its sounds like you floated the valves. Are you sure it was 6500rpm?
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#8
TECH Enthusiast
i revved stock 6.0 alloy bottom ends to 7500 with stock rod bolts. 6500 should be totally fine rev wise.
i wonder if the big end was pulled out of circle with the new rods bolts, and/if they were resize (i know katech say theirs don't do this compared to arp).
PTV? Fuel? tune?
i wonder if the big end was pulled out of circle with the new rods bolts, and/if they were resize (i know katech say theirs don't do this compared to arp).
PTV? Fuel? tune?
#10
#12
Old School Heavy
iTrader: (16)
Tight rings might be evident by galling of the cylinder wall (many vertical scratches worse on the cylinders that failed).
Too tight of piston to wall tolerances can cause the pistons to try to lock up in the bore(aluminum galling on the cylinder wall often gives this away typically)
Piston to valve clearance (This will be given away by broken or bent valves in the affected cylinders
Connecting rod failure (some times this will be given away by heavy damage in the bottom end, but top of the piston might have minimal damage but not always.)
By what little information we have here, I would be tempted to suspect pistons to cylinder wall clearance issue. Either too tight causing the piston to gall and seize in the bore or too loose causing heavy side loads on the piston skirts to the point where the skirt failed and the piston tried to turn sideways in the bore. Either of these could cause the things you describe.
Too tight of piston to wall tolerances can cause the pistons to try to lock up in the bore(aluminum galling on the cylinder wall often gives this away typically)
Piston to valve clearance (This will be given away by broken or bent valves in the affected cylinders
Connecting rod failure (some times this will be given away by heavy damage in the bottom end, but top of the piston might have minimal damage but not always.)
By what little information we have here, I would be tempted to suspect pistons to cylinder wall clearance issue. Either too tight causing the piston to gall and seize in the bore or too loose causing heavy side loads on the piston skirts to the point where the skirt failed and the piston tried to turn sideways in the bore. Either of these could cause the things you describe.
#13
Remember he had 500 miles and 8 pulls on the Dyno on it. If it was too tight the dyno should have shown some type of regression as the temp came up.
#17
TECH Enthusiast
7 and 8, makes my think of a heat issue (heads not bled, properly, air pocket). or fuel distribution issue, borderline tune, maybe lean out due to no jet extensions on lunch.
7&8 go, then 3 is a casualty
7&8 go, then 3 is a casualty
#18
The problem is, that he just came from the Dyno shop. Surely they had it tuned right and jet the extensions in.
#20
TECH Enthusiast