KN_TL

iTrader: (3)

I purchased a set of heads from a member here and it had some nicks on one of the mating surfaces. No big deal so I take to my local machine shop and they say no problem.

Well after checking the head out, they say it looks like someone took a belt sander to it and it takes .007" to make it flat again.

I'm going to check the clearances with some clay but am wondering if anyone knows what the machining limits are and how much valve to piston clearance I need to have?

Also picked up a graduated pipette and will measure the compression ratio IF the valves clear.

Thanks

thisaznboi88

iTrader: (7)

there some marking that shows the service limit. its a round bump

KN_TL

iTrader: (3)

These?

mzilvar

iTrader: (3)

The service manual states:

maximum service limit is .2mm (.008") based on a height of 121mm(4.76")

states head height can range from 120.95-121.05mm (4.762" - 4.766") new

the service manual is a lot more conservative though, ILC took off 40 thousandths from his heads when king motorsports did that work for him, in his thread he stated that was the limit on the piston-valve clearance, that's probably with his big regrind that they put in as well..

https://acurazine.com/forums/perform...mplete-897606/

at 7 thousands should be perfectly fine, that's actually right in the service limit, if someone took a belt sander to them who knows how much they removed though, can measure the cylinder head height to figure it out

KN_TL

iTrader: (3)

Thanks

Could be my shop was being sarcastic. I'll compare the measurements to my stock heads but thanks for the info on ILC's work. .04 vs .007" makes me feel better, but like you said, I am not sure where the starting point was on these heads.

thisaznboi88

iTrader: (7)

I think that image are the service limit indicator. Good information here. I think my here were only cut .013"in. Only did a little Because if decide to swap block I have the option to switch the heads over