Milling on a ka head
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nismo dreaming
- Posts: 248
- Joined: Tue Nov 22, 2005 3:31 pm
- Car: 1996 240sx LS1
Milling on a ka head
My headgasket blew and my head warped about 1800 mm warpage and the factory minimum is 1400. The shop says i could have it done, but they arent sure i would have enough piston to valve clearance and i might have issues. Does anybody know if milling it that much would be still alright??
Re: Milling on a ka head (jaytheman88)
Dayum! Make a teeter totter out of that thing! I think you missed a decimal point somewhere. 1800 mm is like two feet Head surface flatness limit: standard: less than 0.03mm (0.0012 in.) limit: .1 mm (0.004 in.)Resurfacing limit: Cyllinder head resurfacing amount = A Cyllinder block " " = BA+B should not be more than .2 mm (0.008 in. 8 thousandths of an inch)So, to answer your question, you can take up to 8 thousandths of an inch off if you don't re-surface the main block.that is for a KA24DE. What year is yours?
Modified by 420sxse at 1:29 PM 3/8/2006
Modified by 420sxse at 1:29 PM 3/8/2006
So, according to my '92 DOHC manual 0.014 in. is almost double the maximum. Maybe the difference in cams lets the newer ones get away with that? I don't know. If you have .014 in. milled off, subtract that from the warpage amount. Then subtract the allowable warpage from the remaining amount. If it's still greater than zero, you have too much to correct. I highly doubt the max allowable warpage for yours is different than mine (0.004 in)If the machinist is right about the 0.014 in figure: 0.018-0.014=.004 0.004-0.004=0. I wouldn't do it though.
Modified by 420sxse at 2:47 PM 3/8/2006
Modified by 420sxse at 2:47 PM 3/8/2006
Re: (420sxse)
Ok, so I looked up a '97 service manual...It lists the same tolerances. I think what the machinist was saying was that to get within the warpage limit, you would need to take 0.014 in off, and that is way too much. Go visit the classifieds section.