Mahle piston to valve clearance ?
02-04-2011, 11:55 AM
#1
On The Tree
Thread Starter
iTrader: (2)
Join Date: Mar 2005
Location: Detroit
Posts: 182
Likes: 0
Received 0 Likes
on
0 Posts
Mahle piston to valve clearance ? After degreeing the cam (everything checked out ok) I clayed the #1 piston and found a strange condition. The pistons are off the shelf Mahle L92/403 flat tops with valve reliefs. The cam is 232/240, .575/.588 Comp XE. Valves are standard Manley LS3 (2.165/1.59)
I have a ton of axial clearance to the piston (.32" intake and 0.28" exhaust) but radial clearance is as as low as 0.07" on the intake side and barely at the min recommended .100" on the exhaust.
I guess I don't understand why Mahle would cut such deep valve pockets and allow such small radial clearance. The corner is very sharp so I plan to deburr and get my clearance that way but still a strange design for the piston.
Anyone else run into this?
Intake:
Exhaust:
I have a ton of axial clearance to the piston (.32" intake and 0.28" exhaust) but radial clearance is as as low as 0.07" on the intake side and barely at the min recommended .100" on the exhaust.
I guess I don't understand why Mahle would cut such deep valve pockets and allow such small radial clearance. The corner is very sharp so I plan to deburr and get my clearance that way but still a strange design for the piston.
Anyone else run into this?
Intake:
Exhaust:
02-04-2011, 03:04 PM
#2
My Manley pistons were the same way, my heads came unassembled and I placed the valves on the reliefs and they were pretty snug also. But it is a good idea to deburr the sharp edges because that can cause you some knock. I wouldn't worry too much about it though in my opinion.
