camshaft scarring *help*

[VNG704]

So doing a timing chain kit replacement and noticed on the exhaust camshaft lobe under the third cap has a rough scarring or wear around the lobe. what may have caused this? low oil pressure? I should let you guys know that I did a money shift 3rd to 2nd instead of 4th before the timing rattle if that info helps. I can post a pic if needed. Will this hurt my engine? Car drove fine with this, well except for the little rattling which came from the front of the motor so I asumed it was the timing chain. I do have some hks cams but wasn't planning on putting them in yet. Probably not until I know what's going on with that cam lobe. thanks in advance.

[CSUPUEBLOTIM]

Ya post some pictures up.

[the converted]

put it on a compression or intake stroke and see if there is any play with the rocker. You could have bent a valve

[VNG704]

I haven't gotten the chance to get see if the valve is bent/rocker arm play... yet. It's been cold and windy and the way I have the car faced towards the garage door, I'd have the wind blow debris in the motor. I have it faced this way to use the sunlight versus the poor garage lights to work on the car. I kinda regret it because I have a hard time to work under the hood when it's windy, which is alot lately. Anyway I took some pics to show you guys what I'm talking about. It looks like dirt or something has gotten in there and f*cked it up. Also on the second pic, notice the discolored part of the cam, don't know if that has anything to do with it.

from the top:

this one shows the wear on the part under the camshaft:

[the converted]

That would be something got in there and started wearing away at it. You can clean it up and make sure there aren't any rough or raised edges and hope.

[japslapsilvia]

i had the same issue u have, except it was on the intake side, 3rd cam cap.

there are a couple or a compination of things that happend, that would cause this.

lack of oil, maybe the oil squirter tube was cloged and there was no oil there.

debris could have been in there causing the scoring.

im guessing that the cam journal has a groove and the cap and bearing surface has deposit on it.

i took my head to a machine shop and they belived that the head warped or "buckled" and the cam took the excess stress so ur cam may no longer be straight.

depending on hoe bad the deposits are you may be able to fix the issue. you can take a fine sandpaper and clean the debis and replace the cam. the problem with this is that if you do this u run the risk of make the bearing surface out of round which will lead to low oil pressure. another thing is to have the cams bearing surface (all on exhaust side) bored, problem is that it will lower the cams center line. the tensioner will take out the slack but u will still have to deal with oil pressure issues.

was the motor ever over heated?

i had to scrap the head and source another.

GL

[garagelu]

I had an issue with a scored cam but caught it within 200 miles of installing my jwt cams. Turned out to be a clogged oil squirter.

In your case, it looks like something go in there and wore it away. Also if somehow that journal got too hot, it could happen also. That damage looks pretty deep. If you can find a replacement head, I would look into that.

[VNG704]

So basically, the car's ran with low oil before. Either the p.o. had low oil or the squiter was clogged. Best thing to do is find another head to swap in. Saving my new camshafts for the next head, don't want to mess those up. Okay so in the meantime, if I can sand this down or smooth the journal/lobe down, will it be okay to drive?

[japslapsilvia]

yea should be fine to do that, i would just clean it up with some fine grit, just to get it smooth.

then also hit the cam's bearing surface too, (if ur using that damaged cam)

shouldnt be a problem since its already damaged..just make sure and clean ALL shavings out, otherwise u will cause more damge.

[bruinbear714]

And remember to torque it down correctly.

[VNG704]

Yes, I'm going to be using this head until I get my next head. I found a replacement head with no cam caps. This is the head I'm going to use my hks cams in. Would my old cam caps be fine with this or would I need to buy new ones? Going to install that oil pressure gauge I got sitting in my room to watch the oil pressure because of that sanded down part. As far as torqing this, I just tighten little by little and finish with the 6.7-8.7 lbs-ft per FSM. FSM was asking for 1.4 for step 1, then 4.3 for step 2, I couldn't find a torque wrench with anything smaller than 5ft-lbs.

[japslapsilvia]

i would try to find a head that is as intact as possible.

in anycase if u end up using your old cam caps you will need to replace that damaged one.

GL

[tercel drifter]

i didn't read through the whole thing but if valves and everything and mains for cam are still good, why don't you just send your camshaft to a machine shop? they can regrind them and they'll even check for invisible cracks and what not

[VNG704]

well I don't want to spend any money on these cams, I have a set that I'm just waiting for a replacement head for.

question, I found a cheap head that doesn't include cam caps. I've read that new cam caps would need to be line honed with the head. Also that it's rare to find a machine shop that can do this. I'm also betting it's expensive to have done. Would I be able to use old cam caps with using a new set of camshafts if I were to find a different head with it's own original cam caps?

Edit: read some DIY camshaft installs and it doesn't say anything about using new caps. Answer found.
Modified by VNG704 at 11:27 AM 4/20/2009