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Warped Cylinder head tolerances

M

Maraian

Contributing Member
2006 J15, I recently discovered my head has a low spot between the cylinders and am trying to decide between resurfacing or buying a new head.
Does anybody know what the tolerances are?
How warped is too warped to resurface?
thanks
 
Fact ,---All outboard cylinder heads are warped after a few years.------Never mind how bad it is now !-------Just resurface it as per a manual.-----Now it will stay true.---A new cylinder head will warp after a few years !
 
Use a piece of glass and some 180 grit emery paper and rub it on there.-------Takes just a few minutes.------Removes the minimum amount of material.------Does not affect the way the motor runs after doing this.
 
Ok thanks, I had done a quick sanding using 220 grit, but it didn't work. So I got a straight edge and some feeler gauges and found a low spot in the middle at .005" below. the thing is it leaks water out of the edge were it seems to be flat.
 
All heads show that low spot between cylinders !!---------That is the nature of aluminum castings after numerous warm ups.------------Just work at it till it is flat.----Another way is to use some valve grinding compound on the glass to finish this simple job.
 
racerone said:
All heads show that low spot between cylinders !!---------That is the nature of aluminum castings after numerous warm ups.------------Just work at it till it is flat.----Another way is to use some valve grinding compound on the glass to finish this simple job.
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Ok, thanks. I found a video on YouTube that said to start with 80 grit and work up to 120 then 220.
 
Ok so I sanded untill it all looked the same. The middle where it was low was the last spot to change appearance as expected.
But now the middle is a high spot and the two ends ( vertical axis) are low! The straight edge is seesawing on the middle spot. On the horizontal axis it is level at all points. I quess I need to try again?
 
No, light pressure didn't seem to be doing anything so I held it on each end and went back and forth.
I think the piece of glass I was using must have been flexing in the middle.
it took three hours, I can't imagine going any slower than that.
 
It had .005" low spot in the middle, I started using 80 grit till it all looked resurfaced than used 150 and then 220 grit.
the glass I was using must have been flexing in the middle causing the ends to make better contact
 
Call your local auto machine shop and see if they have a belt surfacer, takes about 1 min to fix and it will be flat...
 
kimcrwbr1 said:
Not the case when you press on the outer edges you naturally was rocking it as you sanded. Wrong technique been there done that. About five minutes doing it in a figure eight and you should be good 220 grit fresh sheet.
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The thing is I tried 5 minutes with 220 grit in a figure eight, It didn't work. So I repeated and sanded a little longer the second time, again didn't work. It actually seemed to be leaking water worse.
So then I decided to do a more thorough job with 80 grit and completely resurface.
I quess I'll just keep at it!
 
faztbullet said:
Call your local auto machine shop and see if they have a belt surfacer, takes about 1 min to fix and it will be flat...
Click to expand...
I called the machine shop, he didn't know if a head that small would fit his equipment and they are only open when I'm at work. So I would have to take a day off work just to see if he could do the job. I figured it would be a good learning experience, so far that part is panning out!
 
Ok, I think I finally figured out my problem. I left the glass (of a photograph) in the frame, causing the center to flex down and over grind the edges!
i removed glass from the frame and am finally making progress, although I think I may have already sanded down too much material.
does anyone know what the war page tolerances are for this head?
 
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