1G Machinist cut head 22/1000 need help ASAP....

[95DsManiac]

Hey everyone,

So after finishing up my laser I thought I lifted the head and have been going through coolant everyday. Decided to build the head and do a few other things. After taking it apart come to find out the previous owner put a hose in between the heater hoses and used hose clamps to hold it in place? Hope that made sense it is really hard to try to explain.

Took the head in to get rebuilt along with my newish bep housing only has 15 miles on it and has two broken studs in it. He calls yesterday saying he cut the seats and valves then checked the deck and was warped 17/1000. I was kind of pissed because I used to work at a machine shop and I would always clean the head then check for warp eagle and vacuum before anything. His 40yrs of experience was obviously taught wrong. He then ends up cutting the head an extra 5/1000 to clean it up. Then calls this morning to tell me everything and that he was only able to drill one bolt out of the housing and couldn't get the harder one.

Sorry for the story but I'm pretty pissed. My question here is,

Would it be ok to run the head after being cut that much? This is the second head I got in two weeks that is trash and the person who sold it to me on here isn't replying to my e mails. I already know I'm F'd for the housing and need to buy another one.

Any factual evidence or experience is what I'm looking for, not this book says this and that person said that. I know 12/1000 is limit per the books.

Thanks for your time and god bless,

Anthony B.

 

[darknezz7]

Wow that is complete bs. What machinist does all that before a simple thickness measure and warp check...

I would be convincing them to do the next one free.

You probably know this but.

"New head thickness is 5.200
The Mitsubishi factory manual says a combined total of .008 may be removed from the block and head.

AERA (Automotive Engine Rebuilders Association) says .015 can be milled from the head.

So by AERA specs the Min thickness will be 5.185"

Thicker head-gasket or I have heard of a spacer plate? cometic makes up to a .07 thick head gasket.

Maybe measure yourself to see really how thick it is?

 

[boost97gst]

http://www.dsmtuners.com/threads/how-to-measure-a-4g63-for-cylinder-head-for-thickness.413757/

darknezz you beat me to it.

 

[mitsubishikid]

If the head cant be saved, you might get lucky, and find a good used one from pick-n-pull, and don't forget to bring a measuring tool with you, to see if head thickness falls within spec.

I actually have 2 or 3 spare big port 1g heads lying around this post has inspired me to check them out.

 

[My1GLaser]

Mine has been cut at least .020" over the years. It's fine. I degreed the cams and clayed the pistons with HKS 272s and I have plenty of clearance and thats with a Felpro composite HG. I have adj cam gears to tune out any timing change from the material lost from the head which is probably negligible anyway. I wouldn't worry about it! However, I didn't feel as confident about my cyl head until I went thru all the work of degreeing and claying...

 

[pacn91]

+1^^^ As long as the surface isnt too thin and its been milled straight. All that happens is eventually compression can increase depending on much keeps being milled. If I remember correctly it takes removing approx. .040 of material to raise compression "1 point." obviously you dont want alot of that on a boosted street engine. Just offset it with a thicker head gasket like stated above. Everytime you mill it will retard the cam timing, a tad, so you will want to correct that with adjustable gears. If you are worried about clearance, clay the valve pockets and check. your comfort number will be .100 clearance between the valve and piston. Finally, mind your tune.

 

[donniekak]

I've ran heads cut more than that and didn't have any issues. But,,,,. With your head being warped that bad, I'm betting that the cam journals are not lined up anymore. Try putting some cams in them with no rockers or lifters, use assembly lube. If you can't easily turn the cam with just your fingers when the caps are torqued down, the head is probably junk.

 

[95DsManiac]

Thanks everyone. I feel better about running it,but I will definitely need to be checking the cam journals before paying this guy because honestly I think he did me sooooo dirty because of doing all the work before checking the deck. And then taking out the easy broken bolt even though he couldn't get the other out, now I have to buy another BEP housing. I'll be going over there tomorrow, so wish me luck.

Thanks again and god bless you all,

Anthony B.