Diamond flat top valve notches fit L92 heads?
10-21-2007, 04:38 PM
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Diamond flat top valve notches fit L92 heads? Can anybody tell me if LS2 4.0"flat top diamond pistons have proper valve notch clearance to use with L92 heads? Fly cutting necessary with 250*-260* @.050" cams? Does anybody make L92 specific pistons for 4" bore blocks?
10-22-2007, 06:53 AM
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I read the CarCraft article on the 6.0 motor they built w/ the L92 heads and they cleared the stock pistons fine. I'm going by memory here but I think the article mentioned that the valve angle was different thus giving it more clearance.
10-22-2007, 07:28 AM
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i can't remember if diamond does but i remember some piston company makes a set that has reliefs for those heads.they could always custom make a set for you.i have no clue as for the clearance with standard reliefs.
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10-24-2007, 10:28 AM
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pistons for standard cathedral port heads for factory 15* valve incline or similar styled aftermarket heads with stock valve location will not work with l92 heads. they relocated the intake valve a wee bit on the l92 head. You could take a set of cathderal port pistons and have the notchs recut and that should fix it up.That is of course if you are running a cam with lift and timing that would put the valve near the head of the piston and create a problem. The size of the l92 intake valve being larger move you into collision territory faster then if you had a normal 2.05 vs the l92 2.100
Either way its easy enough to adress this with a competent machinist.
Either way its easy enough to adress this with a competent machinist.
10-24-2007, 04:42 PM
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yup, i have that same engine combo in my s-10 as of last weekend,, runs great and no clearance issues at all,, stock 6.0L with L92 heads, comp cams 228,230 @.050", .571",.573" lift, 112 center,,,
10-24-2007, 09:55 PM
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hope that helps.
10-25-2007, 10:38 PM
#12
The degree they cut the valve reliefs are competely different. I was talking to some of the guys at JE a while ago about something similar. They usually cut the reliefs about 1.5ish degrees more than what the valve angle of the heads are. It might work, but I doubt it would be ideal. I'm a large advocate of custom pistons and getting something specified exactly for your combo.
11-18-2007, 04:23 PM
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ZLEEPER your info is extra helpful as your cam range is close to mi target size.
11-19-2007, 02:51 PM
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Hey guys thanks for all the responses, i got help from Fraser at Speed Inc. he is having Diamond pistons modded for this application for me. There is additional relief work to be done to shelf pistons.
ZLEEPER your info is extra helpful as your cam range is close to mi target size.
ZLEEPER your info is extra helpful as your cam range is close to mi target size.
11-25-2007, 11:21 AM
#20
i am doing a similar combo...using domed pistons cut with L92 valve reliefs in an lq4. looking for 12.5-13:1 compression, L92 carbed intake w/injectors and healthy custom grind cam. should be a nice corn fed, pump gas motor.