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freak
19-05-2009, 01:04 AM
I have dismantled a 3E5F80 8 cylinder compressor which had a broken discharge valve.(This had recently been rebuilt) We have found that the effected cylinders piston has a shorter conrod,meaning the clearance above the piston is 20mm greater than the other cylinders.What would this do to the compressor besides reduce efficiency.Could this cause the valve damage?

ateeq.baig
19-05-2009, 11:32 AM
this is not the cause of valve damage
because your valve does damage because of flappering
if you want to reduce the clearance you can use thick ring

RANGER1
19-05-2009, 11:42 AM
freak ,
Do you mean 20 or 2mm clearance ?
If this clearance is higher than recommended , it would increase cylinder / piston heating .
Because not all ( hot ) gas is discharged from cylinder , and it can't
draw as much cool gas into cylinder .
Expect high temps in this cylinder , which would also reduce valve life due to overheating .
It could also increase oil consumption due to hi temps ,cylinder wear due to poor lubrication and gudgeon pin wear .

freak
20-05-2009, 12:54 AM
freak ,
Do you mean 20 or 2mm clearance ?
If this clearance is higher than recommended , it would increase cylinder / piston heating .
Because not all ( hot ) gas is discharged from cylinder , and it can't
draw as much cool gas into cylinder .
Expect high temps in this cylinder , which would also reduce valve life due to overheating .
It could also increase oil consumption due to hi temps ,cylinder wear due to poor lubrication and gudgeon pin wear .
Thanks for the reply,its my theory too.And yes the rebuilders used a con rod 20mm shorter.Unbelievable.

freak
20-05-2009, 12:55 AM
this is not the cause of valve damage
because your valve does damage because of flappering
if you want to reduce the clearance you can use thick ring
Thanks for the reply.