Cam journal & bearing damage... is this repairable? (pics)

Suprapowaz!(2)

Suprapowaz!(2)

New Member
Apr 10, 2006
2,870
0
0
50
San Antonio, Tx.
While tearing down my motor due to low compression in #1 cylinder I found what I suspected.

rscf30339tk.jpg



rscf30351ae.jpg


So fragments of metal were floating around in my oil. Cylinder bore looked ok with very light surface scratch marks down the bore. Minimal overboring would probably clean it up. Time for some forged slugs.

But it also caused this damage... I'm assuming.

rscf30475ko.jpg



rscf30481km.jpg



rscf30517ls.jpg



rscf30525wl.jpg


So do you guys think a knowledgable machine shop car repair something like this? What would have to be done to fix it? At least lie to me and tell me everything is going to be alright. Thanks.
 
Supracentral

Supracentral

Active Member
Mar 30, 2005
10,542
10
36
One thing is there really aren't any "cam bearings" - it's riding directly on the head surface. I'd pick up a used head somewhere. You could probably have someone make custom cam bearings and machine the head to fit them, but the cost would be ludicrous.

Probably far more than having your porting done over again.
 
N

NDBoost

Guest
why cant you swap the cam's out of a doner head into the ported head?
 
Suprapowaz!(2)

Suprapowaz!(2)

New Member
Apr 10, 2006
2,870
0
0
50
San Antonio, Tx.
Yeah, I didn't know what to call that surface. This is a bummer. I'll just have to take this head in and see what some machine shops will say. I don't want to pay for another port job. There's gotta be some way to fix this. JB weld the surface and smooth it out with a butter knife maybe? j/k
 
F

figgie

Supramania Contributor
Mar 30, 2005
5,224
16
38
50
Twin Cities, Minnesot-ah
won't happen

As Mike (Supracentral) stated, the cam journals on the head are THE HEAD. What I mean is that the cam journals are machines out of the head. This requires welding to fix, if you weld have to anneal the head.

Expect 1000+ dollars for that alone.

Then the machining and line honing of the cam journals and caps. Another$300-$500. Get a new head and port it. Will be cheaper.
 
Suprapowaz!(2)

Suprapowaz!(2)

New Member
Apr 10, 2006
2,870
0
0
50
San Antonio, Tx.
I have a spare head in the trunk. I guess I'll look around to have the spare machined and put back together if I can't get someone to fix it at a reasonable cost. Only I won't spend the money on porting again. Let me take a drive and see what one machine shop says about the head damage. I'll be back in about an hour and give an update.
 
S

Supra

New Member
May 11, 2005
304
0
0
48
Rockford, IL
Honestly, I'd replace the head and cams too BUT....

The oil clearance spec is #1 journal .0014-.0028" max allow .0051". #2-#7 journals is .0010-.0037" with a max allow of .0051".

If you were in the market for a different cam profile, you might be able to have a cam set made with oversized journals and align bore the head. I've never heard of anyone doing this but it should be possible.
 
Suprapowaz!(2)

Suprapowaz!(2)

New Member
Apr 10, 2006
2,870
0
0
50
San Antonio, Tx.
UPDATE: I went to two different machine shops here in town. One has a pretty good reputation, and I haven't heard of any bad things about them. As a matter of fact that's the shop that did my port work on the head. They told me that they can line hone the head, and install a new set of cams. Their price on the cams were $349.95 for both intake and exhaust cams, and roughly $250-300 for the machine work. That's just to line hone the head and plop in the new cams. He said the object of line honing the head was to get any high spots out of those scratches and make them really smooth. I would still see some pitting but that will not affect anything. I didn't get a price from these guys for a valve job, adjusting lash, or resurfacing.

Second shop I went to said the exact same thing. These guys are "the best of the best...... with honors!" Actuallly these guys are #1 here in town. They told me that I didn't have that big of a problem at all. They'll line hone it for $150. Their price on cams are $180 each. They ask me what else I wanted done to the head so I told them a valve job, adjust lash, and resurface the head for a MGH. $700 for the all the machine work including line honing. Cams are seperate. I asked for a mirror finish on the head and he showed me his work. One of his heads that was prepped for a MHG had what he claimed was a 1.0 or less RA. I looked glass smooth. Anyhow, it looks like I'll be going with them. I just need to work a little overtime now.
 
Y

Yeahdoug

New Member
Jun 3, 2005
53
0
0
39
Rochester Hills, MI
Yeah you can have the machine shop cut the caps then align hone them. Just as if you were doing your mains. Only problem is finding a shop that has the equipment to do it.
 
Suprapowaz!(2)

Suprapowaz!(2)

New Member
Apr 10, 2006
2,870
0
0
50
San Antonio, Tx.
The oil clearances should still be in spec cause they're going to align hone no bore it. Here's some more carnage. These are my main bearings. I haven't taken any pics of my rod bearings, but they're about the same.

rscf30291tc.jpg



rscf30280tt.jpg



rscf30275ac.jpg



rscf30266fw.jpg



rscf30254ny.jpg



rscf30241xr.jpg



rscf30237pi.jpg
 
Suprapowaz!(2)

Suprapowaz!(2)

New Member
Apr 10, 2006
2,870
0
0
50
San Antonio, Tx.
figgie said:
main bearings?

I hope to god you are replacing those and not reusing them!
Click to expand...

No no, that's just pics of the tear down. Of course I'm replacing them. Just need to work some massive overtime so I can afford to do so without tapping into my emergency savings. Don't want to freak out the wife.
 
You must log in or register to reply here.
Top Bottom