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Opinions on my cam and head journals

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88BB8B

Proven Member
179
18
Oct 14, 2016
Coldstream, BC_Canada
Hey everybody. So my freshly rebuilt 4g63 chewed through its bearings, and gracefully distributed damaging particulate everywhere you don't want it. Looks like it didn't catch one cam as bad as the other.

-The first pic is what most of my head journals look like.

-the second pic is what the worst 2 look like. The orange is just some rust I accidentally whiped on it with my finger.

The 3rd and 4th are the worst 2 journals on either of my camshafts. The discolouration is a little rust from sitting a year.

I'm not very experienced with these engines yet, and I'm not sure how much damage cams and head can have and still be okay. The scratches aren't very deep, certainly nothing compared to my crank main and rod bearings, but I can feel the worst of them with my fingernail relatively easily, some of the less damaged cam journals pass the fingernail test. I'm planning on running W40 oil if that makes a difference with clearances.

All opinions greatly appreciated.
 

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7 bolt heads are still pretty easy to get, I would probably set that one on a shelf and try to find a bare head to swap the valves over to, if these are stock cams I would trash them, if they are aftermarket you could send them to someone like a camshaft re-grinder and have them spray weld them and regrind them.
 
The photos do not look to bad for the head, If you can find another one easy enough it may be the route to go. If that is not a option being i cant feel it myself i cant make a call. I can tell you the head on my car right now has some cam journals that are scored lightly but not quite enough to feel. But this is a race motor that is torn down regularly so if it became a issue i would take care of it.
 
The head looks fine to me, and the cams can be polished and probably be fine. but if they're stock, it's so easy to find more stock cams in perfect condition, there's no reason not to get different ones or aftermarket.
 
If I can get away with a polish I would be happy. My sitauation is that Im in my last semester of engineering and I dont have a lot of cash atm, so if I can't get this thing back together safely without buying new cams and head, then I wont be able to until I get a payroll going, and I've had this car apart over a year already.

Am I correct in assuming if the clearances are off, or the cams and journals are too rough, that they will send shrapnel that will take out my other bearings? Does the camshaft need to be as perfect as that crank? (Since less force on it I'd assume no?)
 
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To start with, minus the front cam journals(ones by the cam gears) the bottom side of the journals are non-load bearing surfaces, therefore minor damage to that face is not a concern. I'd be much more interested to see what the cam caps looked like since they are your load bearing surface. As far as the cam, I'd suggest polishing and sticking them back in since a good oil film will compensate for a lot in the way of minor surface imperfections.

I'm also assuming that you're planning on taking the whole engine back apart and cleaning out all of the oil galleries, correct? If not, I'd highly suggest it to make sure that you don't have any lingering trash from the ruined main/rod bearings.
 
I hadn't even thought of that but that totally makes sense in regards to which sides of journals are load bearing. I'll post more pics of the caps. If the caps are scratched can I use something to polish them a little? being careful not to remove too much material of course.

As for the rest of the engine, that's already been done. I've got an OEM reman crank, new bearings including balance shaft. New oil pump, oil cooler/filter housing, new timing belt I've got some eagle rods I might use, but not enough $ right now for forged pistons so I might go with OEM evo stuff. Block has been hot tanked, honed and bores and journals checked. I still have to clean out the head but I'll do that after any work I might need to do to it.
 
Come on man, you're in school for engineering (as am I) and you didn't take into consideration which surface was load bearing??????? *tisk tisk*.(kidding around BTW).

Yes, caps can be cleaned up to a degree, but definitely don't remove much material.
 
Haha, I just needed a little reminder ;) and if I decide to try clean up this head, does anybody know what a safe oil clearance for the cams would be, running 40 weight? All of the head hardware is stock.
 
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