Head Warped where cams sit?

[Sp1kE]

I just talked to the machine shop, I brought him 2 heads. He said that he put a straight edge on both of them where the cams sit and it was uneven(I forget the measurement) he said the straight edge could rock back and forth because the middle had a high spot. The bottom surface is supposidly fine.

He said that it might even out once everything gets torqued down but hes not 100% sure. He has an e-mail out to others about the issue. I said I would post on the fourms.

Is this normal? Has anyone run across this before?
Is it just coincidence that both heads are warped like that?

 

[BogusSVO]

its cam tower warp... yes it is common to a point, most all OHC heads have some....

if it is bad, it can gaulled the cams to the head....

to check how bad it is.... remove the HLAs and followers, lay the cams in, and torque the cam caps to specs...
if you can turn the cm by HAND then you will be fine, if it feels sticky, or will not turn by hand, the cam bore needs to be aligned bored/honed

 

[donniekak]

This is what happens when you resurface a badly warped head. When a head warps the whole head warps. When it is torqued down, it flattens back out, and everything is lined up. If you flatten just the bottom, the cam journals stay out of line. On a badly warped head you should have them heated and fixed.

 

[BogusSVO]

donniekak... yes the head should be strightened, but since the head has been milled, that is a moot point, that should have been done before the head was milled

 

[Sp1kE]

The head was not milled. he noticed this before starting any work.

 

[BogusSVO]

The head was not milled. he noticed this before starting any work.

the head could have been milled before this go around in the shop....

if the machine shop dosnt know how to check for cam bind, then you need to get your parts and go somewhere else.

I have seen heads with as much as .007 com tower rock and the cams spin fine
keep in mind these were for stick engines, anything with some serious build to it, they need to be as close to perfect as you can get.

 

[Sp1kE]

Ah, gotchya.
This guy seems to know his shit. I already switch shops once when the guy said not to align hone when switching to main studs.
I think the new machine shop was boggled that both heads I brought him, had the exact problem.

 

[BogusSVO]

if they deal with alum DOHC heads on a daily basis.... they would know its common

 

[Sp1kE]

Ya they dont, they are more of a v8 race shop. He said he has heard of people who will heat them and torque them down to bend them back.
I asked about boring or align honing the cam castles, but he said he doesnt have anything that small and it would cost a fortune.
Should I just ask around to see if people can "bend" this head back. Or should I go find a 3rd head?

 

[Dewayne Waldron]

I had a similar problem to this and was told that the head had been machined so much prior that the warp couldn't be fixed. Really?

 

[donniekak]

In my experience it is cheaper to find a good core, than having tons of machine work done to a bad one. There are millions of 4g63 heads out there. Most of the salvage yards where i live sell them for less than $50, for a bare head.

 

[BogusSVO]

has he even just bolted the cams into the bare head and checked them?

if he has not, then he simply dosnt want to deal with you or your head

yes I have strighten several heads, it cost about $100, its not hard to do, just takes time and some special equipment. and the head may have to be heat cycled several times to get it close.

as far al the line bore/hone of the cam jorunals, that is a special piece of equipment, basicly a small version or a main bore/hone machine.
That cost about $100-125 per cam journal set up

dewaye... most any alum head can be fixed, but sometimes the cost will be more than just getting a new/diffrent casting...

 

[Sp1kE]

He already did all my bottom end work, I am quite satisfied with that.
He flat out told me he has not bent a head back into shape before, he just said find another one and bring it back.

If I go by those prices, the head needs to be straightned for 100$, and align hone each cam journal to get it perfect, that would be 350$ just to get the head into good shape.

I will try and find another core. Or call around local to see if anyone wants to try and bend my head back.
(I doubt it because I had to drive an hour away to get a machine shop that can align hone and balance.. gr)
I appreciate the help BogusSVO, and everyone else.

 

[BogusSVO]

chances are that the next 9 of 10 heads you buy, will have cam tower warp to some point...(unless you find a NOS Casting)

you still havent posted if the cams turn in there bores......

 

[Sp1kE]

they turn. but dont feel right to me...
I got a 3rd head, i will see what the outcome is.
I also found a place that can try and heat/bend it back.

 

[Sp1kE]

3rd head had a spun cam holder.
head #4 was the money maker, its build and on my block. Thanks, guys