Ported 241 on an LQ4?
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From: 2 Miles from the Brder Wall, Tx
Ported 241 on an LQ4? I have a set of ported 241 heads that flow in the 290's and was thinking of putting them on a LQ4 along with an SI7 (238 244 .605 .612 110). Should i mill them or leave them alone? I really want compression around 10:5:1..Thanks for ur imput.
Should I mill the heads or go with a 0.41 head gasket?
06 LQ4
LS6/S3 TB
Ported 241's w/PRC
SI7 238 244 .605 .612 110
LS7 Lifters
ASP
LPP LT's
LS7 Clutch 4:56 Gears
Should I mill the heads or go with a 0.41 head gasket?
06 LQ4
LS6/S3 TB
Ported 241's w/PRC
SI7 238 244 .605 .612 110
LS7 Lifters
ASP
LPP LT's
LS7 Clutch 4:56 Gears
According to the excel calculator I use:
4.000" bore
3.622" stroke
4.065" gasket bore
0.040" gasket thickness
8cc piston dish
0.000 deck clearance
I'm getting 10.5:1 on the nose with 62cc heads. Problem is, you could run into PTV clearance issues after milling and removing that much from the gasket thickness. You'll have to check, and you may need to mill more to make up for any clearance grinding if required.
Hope that helps!
4.000" bore
3.622" stroke
4.065" gasket bore
0.040" gasket thickness
8cc piston dish
0.000 deck clearance
I'm getting 10.5:1 on the nose with 62cc heads. Problem is, you could run into PTV clearance issues after milling and removing that much from the gasket thickness. You'll have to check, and you may need to mill more to make up for any clearance grinding if required.
Hope that helps!
the problem with that is, the LS motors arent 0.000 deck from the factory. they usually come out of the hole .005-.008"
also, a 6.0 gasket i think has a 4.085 bore.
also, a 6.0 gasket i think has a 4.085 bore.
Looks like there are a lot of possible gasket sizes. I found 4.020, 4.030, 4.065 and 4.085. The 4.065 was a GM MLS, but that wouldn't come at .040 thickness. There are a lot of small variables, so without all the measurements, its still just a guess-timate.
For what it is worth, I was researching pistons for another thread yesterday. I can't recall now if it was Mahle or Wiseco, but one of them stated that the deck height on a 6.0L block was .010 taller. If you've measured one though, I would take your measurement over any text.
Looks like there are a lot of possible gasket sizes. I found 4.020, 4.030, 4.065 and 4.085. The 4.065 was a GM MLS, but that wouldn't come at .040 thickness. There are a lot of small variables, so without all the measurements, its still just a guess-timate.
Looks like there are a lot of possible gasket sizes. I found 4.020, 4.030, 4.065 and 4.085. The 4.065 was a GM MLS, but that wouldn't come at .040 thickness. There are a lot of small variables, so without all the measurements, its still just a guess-timate.
on the deck height deal, its simple math really. i know ther are some variances in castings and such, but for simplicity, if you know the compression depth of the piston you can figure it out.
for instance, well use my setup.
i have a 9.2182 deck height on my 6.0 block after i milled it. (i know its low)
rod length is 6.125
piston compression depth is 1.0982 (custom CD)
stroke is 4.00
the formula is
(stroke/2) + rod length + compression depth - deck height
so...
2 + 6.125 + 1.0982 - 9.2182 = .005 out of the hole
now i put this together myself to acheive a .005 negative deck height because i wanted to keep the piston in the hole as much as possible to avoid hot spots in the combustion chamber and keep the flame front traveling as smooth as possible. but i had to bring it out a little bit so i could run a thick enough gasket to keep from pushing it out under a huge shot of nitrous.
if you can find the stock CD of the 6.0 pistons, and the stock lentgh rod which i dont know any of these off the top of my head, you can find out how far the pistons **should** come out of the hole. assuming a 9.240 stock deck.
