Jump to content
Ultimate Subaru Message Board

Engine cylinder head stains


Recommended Posts

These stains remain after an hour of scrubbing with carb spray, plastic scraper, shop paper towel, and MORE carb spray. From what I saw on this engine before it was installed was some brownish sealant at the water jacket area where the previous gasket was visible at the edges.

I cannot catch any of these stain marks with my fingernail and all is finger smooth. So it is some kind of stain on the aluminum . A shown here, the rebuilder chose to add sealant at the water jacket areas. Also between the cylinders.

I have a Felpro Permatorque gasket ready to go. EA82 non-turbo.

IMG_1317.JPG

IMG_1325.JPG

Edited by rickyhils
add pics
Link to comment
Share on other sites

I have ever only once not surfaced Subaru heads before new head gaskets - lasted three months before it started choofing in coolant. Just made it home.

EA81 of unknown background sat eight years, I sorted it, then let it sit six months when fresh fuel leached out gums and varnishes from inside fuel tank walls

This stuck up valves, caused to pushrods to bend, so new gaskets and went well, pulled strong, was quiet, then all of a sudden....

Stains ?? The least of your worry surely?

Edited by Step-a-toe
Link to comment
Share on other sites

I use a thick 4" putty knife (with a flat edge) (not sharp like a knife) to scrape the surface and stay as flat as possible on the surface. The most important thing is a flat surface. If the surface is flat with a straight edge now, and you work at those "stains" you will end up making depressions in the surface. Previously, if there were depressions in the surface, the gasket or sealer filled them. So, if those "stains" are not protruding from the surface and it is flat, you're good to go.

  • Like 1
Link to comment
Share on other sites

Stained, yes. And this block surface is Smooth to the touch. I can not feel anything. Nothing catches by fingernail At All. No protrusions.

The head cleaned up nice. This head has no overheating issues or flatness issues. Removed from engine only to check valve condition.

The sealant compound was not needed and that is what caused the stains.IMG_1353.thumb.JPG.17f4742720c68fe23f84af40614f5092.JPG

 

Edited by rickyhils
Link to comment
Share on other sites

those stains are head gasket residue the head probably isent flat or it would be more even

check out this thread on diy head resurfacing cant hurt anything to give it a try ive had realy good luck doing this my self and not much different than how we did it in the shop in the olden days 

 

Edited by ferp420
  • Like 1
Link to comment
Share on other sites

i'd resurface it, you can do it yourself easily for cheap and quick, no machine shop or days of drop off/pick up needed.  every one i've ever done has high and low spots so i wouldn't want to skip the step. for a long term seal through combustion chamber temp heat cycling, vibrations/expansions/contractions, and seasonal temperature variations I'd prefer ideal surfaces, particularly since it's so easy to accomplish. 

that being said - i would bet you can install it just fine without any issues, or no immediate issues anyway.  i think years ago i've installed some like that before without any short term issues. 

Edited by idosubaru
Link to comment
Share on other sites

Thanks for the info.

Head looks clean and has no overheating issues. Recent operation had no issue at all on ability to seal.

Only purpose for removal was to triple check valve condition.

Stains ONLY on engine surface where [questionable use of] brown colored sealant made contact AT WATER JACKET AREAS ONLY.

Compression sealing will be ok.

 Purpose of my OP here is to hear from you guys as you've "been there-done that" . My experience is that I once put gaskets on the removed EA82. That was back in in 2008 and after 160,00 miles they held up just fine. But doing it the first time and being successful is still no substitute for previous experience. Sometime we noobies "get lucky" and become over confidant.

I will be installing head now. Felpro Permatorque .

*** Old Gloyale post said finish up this final sequence:  Go to 45 ft/lb. Back off 90deg. Retorque to 45 ft/lb . Then a final 90deg.  I can see how this should bring a more reliable final clamping pressure, rather than just relying on what the torque wrench says.  I have a salvaged engine I can practice on.

Link to comment
Share on other sites

19 minutes ago, DaveT said:

I use the post apocalyptic resurfacing method to get rid of the marks from the fire rings.  That us #1 priority.   By then, the rest should be clean.

DaveT-  Yes. That is the ONLY way to be sure of the head.  However, on the block surface at the fire rings I can only give it my best shot with carb spray, plastic scraper, and paper shop towel. I'll work on that for 30 minutes and then I will have to call it quits and go with it.

Link to comment
Share on other sites

2 hours ago, rickyhils said:

DaveT-  Yes. That is the ONLY way to be sure of the head.  However, on the block surface at the fire rings I can only give it my best shot with carb spray, plastic scraper, and paper shop towel. I'll work on that for 30 minutes and then I will have to call it quits and go with it.

Sounds like resurface is out of the question, in all likelihood it'll be fine.  i've rolled with them like that before.  I wouldn't put any additional effort into cleaning or removing that discoloration than what you've described if resurfacing isn't an option.  Definitely don't wire wheel it or anything like that. 

Link to comment
Share on other sites

Idosubaru-  First - Let it be said that we all highly value the advice from DaveT. However in my present situation I can only go with it as is, so your advice is as reasonable and practical as any at this point. The fire rings are not "deep" as they barely catch the fingernail. I'll do ft/lb sequence 22, 37, 55.  Then, I'll just drive the car and CHECK COOLANT AND OIL every chance I get. 

A side note:  As far as the ancient EA82 goes- here is a FWIW comment. On a junk EA82 block I tested some head bolt torque amounts. I worked up to 70 ft/lbs, with the bolt coming back out clean with no aluminum pulled. AND - One of the bolt holes was Heli-coiled 12 years [160,000 miles] ago and it went to 70ft/lbs just fine. And, against all good advice I installed two [2] coils in that same hole. I carefully measured so that there was a gap between them. AND - the stock EA82 head bolt hole accepted the Heli-coil tap without need to drill. At the time it was either take a chance or junk the car. The new threads were cut without a snag.

don't we love it!

Link to comment
Share on other sites

12 hours ago, rickyhils said:

Are you saying while engine is in the car?

that would get tricky in the car you could do it but gravity wont help in the car take the engine out its easy enuff

i used to change motors for my smog test the mongral had to come out and the stocker back in with stock exhaust then after the smog test back in with the monster and custom exhaust its kinda like doing a tune up its so easy

 

Link to comment
Share on other sites

Block is much much thicker, and under almost no stress in a direction than can effect head sealing. The engine literally trys to blow the head off, and it's only held down by the head bolts. Plus it needs holes for intake/exhaust, cam placement, etc. That's why 2 stroke heads almost never fail. They only need to hold a sparkplug, plus maybe some cooling.

 

I would never put heads back on without atleast a quick stoning. If that shows any unevenness then I would level them.

Link to comment
Share on other sites

18 hours ago, ferp420 said:
41 minutes ago, Ionstorm66 said:

I would never put heads back on without at least a quick stoning. If that shows any unevenness then I would level them.

The left head was sealing ok. Only reason for removal was to verify condition of the valves. After lots of cleaning with carb spray, plastic scraper, and paper shop towel I just put the head back on.

 

Edited by rickyhils
Link to comment
Share on other sites

7 hours ago, DaveT said:

The block hasn't usually needed as much.  I have a piece of flat aluminum channel I wrap the sandpaper around, and use that.

So, I imagine that the channel should be 11'' x 7'' for flat coverage. End with 320 grit?

 Have read that a shallow fire ring might be ok, meaning only slightly noticeable using fingernails.

Link to comment
Share on other sites

No the aluminum channel is only 2" wide.  It's long enough to span the width plus a bit.  The idea is just to touch any high spot, or stuck crud.  I don't try to remove a lot of material.   Make sure you hit all areas evenly.   The ones I have done have not been bad.  The headgasket seals against the steel cylinder wall, as opposed ro the aluminum on the head side, so there should be less imprint. 

  • Like 1
Link to comment
Share on other sites

1 hour ago, DaveT said:

No the aluminum channel is only 2" wide.  It's long enough to span the width plus a bit.  The idea is just to touch any high spot, or stuck crud.  I don't try to remove a lot of material.   Make sure you hit all areas evenly.   The ones I have done have not been bad.  The headgasket seals against the steel cylinder wall, as opposed ro the aluminum on the head side, so there should be less imprint. 

OK. And any need to remove block dowel pins?

And. I see you are electronics engineer. I fixed the EGR cel code 34 by changing out a transistor array chip inside ecu. Dummy load 35 ohms worked but then down the line the chip failed. So, will try 80 ohm 5 watt dummy load.

  • Like 1
Link to comment
Share on other sites

You need a 5watt resistor for 40 ohms @ 12V, especially when you account for the ambient temperature.

I never used a resistor.  I found that Toyota solenoids from the same era are much more reliable - I am still running the same ones I got at a scrap yard in the late 80's.

  • Like 2
Link to comment
Share on other sites

The dowel pins, I didn't remove, just work around / avoid them.  The blocks I've dealt with barely needed anything.  I just used 220 grit, and count strokes if you have to, so you don't over do one area.  Use single edge razor blades or utility knife blades perpendicular as scrapers to get the gasket junk off without shaving aluminum.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...