I had my head rebuilt at Dover Heads Greenville SC. I was charged 276 after tax to:
1) Disassembly, bead blasting
2) Valve job
3) Surface head to make sure its true
4) Replace 8 valve guides
5) Replace all valve stem seals
6) Reassemble


















My concerns are:
1) Is it normal that they bead blasted the cam journals? To me this sounds nuts or is this normal?
2) Aren’t there O rings that go in those spots where the dowel pins go?
3) Why didn’t the shop check and see the groove in the cam journal? This is not correct right?

Thanks for any help-

 

Q: 1) Is it normal that they bead blasted the cam journals? To me this sounds nuts or is this normal?

A: Blasting the cam caps no.

Q: 2) Aren’t there O rings that go in those spots where the dowel pins go?

A: No, cam cap dowels that locate the cam caps don't have o-rings. It's only that one in the center of the head.

Q: 3) Why didn’t the shop check and see the groove in the cam journal? This is not correct right?

A: There's going to be grooving, that's normal unless it's really deep or it looks like the cam siezed which is not your case.


Big ups!!!

 

Thankyou for taking the time to answer my question.
So do you have any recommendations on what I do now? Is this head usable after bead blasting of the journals?

My gut feeling is no, but I have never dealt with this sort of thing. I would assume though, that by bead blasting it, material was taken off, and the finish that the cams normally ride on is gone.
The shop stated that it will come back, but that is essentially polishing them with my camshafts and eating them up.

Thanks for any input!

 

Hit the caps with a little fine steel wool to re-polish.

 

polish it out, wont be a problem, just make sure to not damage the journal housings.

 

Alright Ill do that and see how it goes- thanks Master

 

If im not mistaken, shouldn't all bearing surfaces be avoided when media blasting?
I mean, you are changing the microsurface a little bit.
Id plastiguage it just to be sure. Cant be too safe right?

 

Ive never bead blasted the cam journals. I dont like that, plastiguage to be sure.

 

Yea, I will plastigauge, can anyone recomend me clearances for this? I will check this weekend, and then contact the machine shop if anything is off- thanks!

 

the journal are never to be blasted... get it polished back out.. why whould they bead blast that head? they coulda just hot tanked it a few times to get all the grime off.. if that was me i would be mad... seriously.

 

What solution is used in a "hot tank"?

 

I've seen shops use both lye and acid? If I recall from chem. class, bases eat up Al.
Caustic etching comes to mind also.

 

I tried polishing it out a little bit, but it feels as if its no where near as smooth as it was before-

I want to plastigauge it, but cannot find a spec it should be within?

 

If anyone should be polishing it out it should be the machine shop. you should also let them know that if you start having cam problems after assembly they owe you a head.

I would be pissed, no reason to blast the bearing surface and introduce a bunch of surface imperfections.

 

Is it just me or did someone else notice this. From this pic you can see the dowels are the same color as the cam caps. Usually these are steel and have a shiny luster to it. I wouldn't think bead blasting would give it the same color as the caps because is not alum? but then again I don't have experience with this process. To me it looks like the head was lightly coated/painted?

 

Looks blasted to me.
From what ive seen if you use the same media on different material the surface
finish will look the same unless you change the psi.

 

Im pretty sure the head has been soda blasted, which is why nothing shines any more. If you bead blasted that head bearing surfaces should be the least of your worries.

 

The shop should not have blasted those surfaces BUT I see a probable reason why they did.

Looking at your rocker arms, they look to be stained brown which is an indication of extended periods of running without an oil change when an oil change is due. The whole valley of the head probably had that stain, and they blasted it clean. Again, they shouldnt have done that, but thats probably why they did.

 

camshaft-to-holder oil clearence
standerd(new)0.0020-0.0035
service limit 0.006

 

Thankyou so much for those specs! Tommorow morning ill give it a check and see what its at- I polished out 2 of the journals, and it still isnt nearly as smooth. The shop of course claims that they do this with every head and its no big issue- I am thinking that they normally do this, but a lot of the time the heads have bearings for the cams so it makes no difference

 

Just to update this, I found a few more issues with the head, and after calling, was told that I am wasting the managers time... Avoid Dover Heads at all costs please.

 

put the head through the window

 

id actually measure that instead of plastigauging it. At the very least take it to a machine shop and have it measured, it wont take long. Either a dial bore gauge or snap gauges and than measure the cam journals, much more accurate that way.

 

never mind. lol

 

i mean how much time does it take to gorilla tape the cam journals nicely...shotty craftmenship i would not go back there again had it been my money at stake...