Are these Subaru heads savable?

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Huie83

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I purchased a 99 Subaru Outback to work on over the winter. One thing it needed was head gaskets. They had been done at some point in the cars life but the quality of the gaskets was questionable.

Got the heads off and discovered whoever worked on the car last really dinged up the area where the cam seals sit. Its a shame because the rest of the heads are pristine.

So, to all of you machinists, are these fixable? Can they measure the seal area with the cam cap installed and just sand or machine the raised areas that protrude into the seal area out. It seems to me its possible as the seal just sits in there. or should I not worry about it ans just install new seals? the old ones weren't leaking at all.











 
You can remove most of those marks with a file, enough to drive the seal in cleanly. Who cares what the outside of the head looks like? (though it looks like it was attacked with a hammer and chisel by a moron who hadn't ever done seals before).

The area by the cam bearing where the seal makes contact, after it is fully seated, is all that matters. The bevel is nice to help you drive the seal in, but doesn't matter for sealing. So, just clean up those chisel marks so that they don't stand proud of the bevel and those will be fine...

The 3rd from last picture, however, with the groove that cuts through the seal surface, would worry me a bit. If the seal sits inside that gouge/groove, then no worries...if not, then you might get away with a bit of sealant like Hylomar, or perhaps an oil resistant RTV, just a dab, to fill in that groove. Take an old seal, place it in that spot and see how much of the groove overlaps the outside edges of the seal itself...
 
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yeah wouldnt worry too much about it, file down the rough parts if you want to. main worry of course is you are re-doing a HG job, make sure the heads are FLAT.
 
Thanks for the replies, I'll bring them into the machine shop to get decked and gone over and see what they say about the dinged up areas. I didn't think they were scrap but I posed on a few Subaru forums and everyone thought they were trash. Great to get some more opinions.

I'm not sure what the heck they were thinking when working on these. If they were trying to create a tighter seal around the cam seal I can think of better ways to do it! Scary part is accoring to the previous owner, the job was done at a Subaru dealer....
 
Originally Posted By: OneEyeJack
You need to find a shop that fixes things. Most shops replace things.


That's a great point. I have a few shops close to my work I am going to swing by with the heads tomorrow. Even if they won't fix the cam seal area, I can handle smoothing that out. Supposedly with Subaru heads you can slip the cam seal on the cam before you install it. Then you just put the top cam cap on and tighten it down to squeeze the seal in there.

I guess its worth a shot over finding used heads in good shape. Plan B will be new heads. I already sourced a set and when they arrived they were in rough shape. Cam journals and caps were all chewed up, almost like something was in the oil for a while, yikes...

No local yards around me have a set of heads so ordering online sight unseen has proven to be a [censored] shoot so far.
 
No problem. Just file it Down and finish of With a fine emery cloth. The only reason is that scars like Those will have a verry small tendensy to start cracks.
 
Maybe you have lots of time on hands. But my versed mechanic spends near 8 hours removing or reinstalling a Subie motor that has to get pulled. Seems like a risk for a potential failure.....
 
Originally Posted By: madRiver
Maybe you have lots of time on hands. But my versed mechanic spends near 8 hours removing or reinstalling a Subie motor that has to get pulled. Seems like a risk for a potential failure.....


Good point. It is a point of failure, how much that is increased by reusing these I don't know. I do know it has been like this for 23K miles and they weren't leaking when I removed the heads.

If the machine shop thinks they won't hold up when fixed, I definitely will look for another set of heads.
 
File down the gouges until they're smooth, fill in the scratches in the bore and cam with JB-Weld and carefully sand it down with sandpaper, working down to fine(1000-2000 grit) evenly.

If the missing chunks of metal scare you, a machine shop could weld or braze some filler rod and work it smooth. If you're having the head machined, might as well...
 
Originally Posted By: madRiver
Maybe you have lots of time on hands. But my versed mechanic spends near 8 hours removing or reinstalling a Subie motor that has to get pulled. Seems like a risk for a potential failure.....


I'm guessing your versed mechanic has a very nice boat.

In a proper shop eight hours to pull an engine is padding. Even on a turbo Subaru. NA 99 outback 2-3 hours out, two in is very doable. Yes, I've done it. I'm not a certified tech, but there's nothing complicated about pulling or installing these engines. Once the radiator is out you have plenty of room. And that is very easy to do.
 
As for the fix, I'm not so sure.

But for the comment about trying to keep the seal in, that may be legit.

The only Subaru engine related failure we have had in the family was on my MIL's 98 legacy outback wagon. The engine pushed out the cam seal.

Luckily it happened in our driveway. Since it pumps oil out faster than you can dump it in when it happens.

It is somewhat likely that the dealer working on it knew of the problem and took a hamfisted approach at a solution.

I would as your machinist about fixing the ugliness and ask about way to ensure positive seal retention.
 
Thanks for all the input, greatly appreciated. I do think the dealer was trying to peen the seals in there. Why they did such a goober of a job doing it will probably be a mystery forever.

I have the heads with me at work today and will drop them off on my way home from work. I'll let you all know what the machine shop says.

Also, if they were trying to retain the seals and I get the sealing surfaces flat again, has anyone ever used rtv, anaerobic sealant or aviation sealant to keep cam seals in place? It does kind of worry me that the seals will back out once the sealing surfaces are smooth again. From reading last night I guess lots of people have good luck with this stuff http://www.amazon.com/Permatex-80019-Avi...viation+sealant
 
The tight fit of the seals is what holds them in place. I would add nothing unless the shop manual specifies it, and they generally don't.

The only exception to the above would be that one groove that I mentioned...if it goes completely under the seal, then I might try a tiny bit in the groove alone, in an effort to keep from replacing the head...

The sealing surfaces themselves on your heads look fine, except for that one groove/gouge. The damage is all on the outside of the sealing surfaces.

I would smooth out the damage with a file or rotary tool. Do NOT touch the sealing surfaces. But you don't want those burrs sticking up when new seals go in as they can (likely will) damage the seals as they're driven in.

Even if you can install the seals on the cam and then assemble the head, as you mentioned, I would clean up those gouges and burrs. You may have to replace a seal in the future, and cleaning up those burrs now could save you a ton of hassle later.
 
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Originally Posted By: Huie83
Also, if they were trying to retain the seals and I get the sealing surfaces flat again, has anyone ever used rtv, anaerobic sealant or aviation sealant to keep cam seals in place? It does kind of worry me that the seals will back out once the sealing surfaces are smooth again. From reading last night I guess lots of people have good luck with this stuff http://www.amazon.com/Permatex-80019-Avi...viation+sealant


I have used the Permatex red aviation sealant on many seals with success. On the head in your example, I would dress the knicked up areas until smooth with a very fine sandpaper, clean with a degreaser, then apply a *very* thin layer of sealant in the seal bore, and gently push the seal in. I have done this on probably 15-20 seals and never had one leak or back out.
 
Originally Posted By: quint
Originally Posted By: Huie83
Also, if they were trying to retain the seals and I get the sealing surfaces flat again, has anyone ever used rtv, anaerobic sealant or aviation sealant to keep cam seals in place? It does kind of worry me that the seals will back out once the sealing surfaces are smooth again. From reading last night I guess lots of people have good luck with this stuff http://www.amazon.com/Permatex-80019-Avi...viation+sealant


I have used the Permatex red aviation sealant on many seals with success. On the head in your example, I would dress the knicked up areas until smooth with a very fine sandpaper, clean with a degreaser, then apply a *very* thin layer of sealant in the seal bore, and gently push the seal in. I have done this on probably 15-20 seals and never had one leak or back out.


Thanks, that's what I was looking for.

I dropped the heads off over lunch. They laughed at the fact someone would do that to a head, but had no doubt they were still usable. They are going to smooth out the seal areas and make sure they are round to accept the new seals. They are also getting a resurface, pressure test the valves, check for cracks and just generally check them out.

Should be ready next Tuesday so I'll post pics when I get them back.
 
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