Cracked E12 Head? Swap to my spare 121...?

[Son of Marty]

I can't off the top of my head think of where high pressure oil comes close to the exhaust port, where the studs are a common leak area. when you reset the ex manifold studs remove the valve cover and stuff a shop rag as best you can over the stud holes on the top row, clean the hole with brake clean and loc-tite them in place, remove the rag and on to the next hole.

Edited November 8, 2022 by Son of Marty

[tech71]

7 hours ago, Summit321 123 said:

You can see a seam of oil coming out of this stud I pulled. I dont think this is what I observed however.

 

7 hours ago, Summit321 123 said:

I doubt this was the root cause.

I dont, you would be surprised how much oil will get past the studs and where it will migrate.

Do the top overhaul for sure and install top exhaust manifold studs into clean, clean, clean head with red loctite or hi temp silicone. Not too much.

[Summit321 123]

23 hours ago, tech71 said:

 

I dont, you would be surprised how much oil will get past the studs and where it will migrate.

Do the top overhaul for sure and install top exhaust manifold studs into clean, clean, clean head with red loctite or hi temp silicone. Not too much.

Will do. I dissasembled the head yesterday and dropped it off at a machine shop. He got back to me today and said it had already been ground and 15 thou was removed. He noticed it was still warped and that he would need to remove another 7. According to spec he said that would leave it just within limits. Does anyone see a reason not to go so thin?

I dont think he pressure tested it yet.

Valve guides were good but stem seals are bad. Based on his observations he thought the most likely source for leaking was the stem seals and warping.

Parts:

Do I need new head bolts? Is there a thicker head gasket or P/N anyone recomends for my situation? Anything that is seriously recomended that I replace in the valve train (Springs, rockers, ect.) I am pushing the pistons out for new rings while the head is off and honing cylinders any recomendations for specific P/N on rings? Any thing else in bottom end (connecting rod bearings, or wrist pin)

Thank you all for your responses.

 

[tech71]

37 minutes ago, Summit321 123 said:

and 15 thou was removed. He noticed it was still warped and that he would need to remove another 7. According to spec he said that would leave it just within limits.

Thats a lot,   need to measure the cylinder head thickness once its flat.

You will probably need to use a thicker head gasket, hope thats enough

Edited November 8, 2022 by tech71

[tech71]

49 minutes ago, Summit321 123 said:

Is there a thicker head gasket or P/N anyone recomends for my situation?

Standard thickness is 1.5mm, a thicker version at 1.8 mm is also available. Hopefully the 1.8mm gasket will work for you.

After that.... it gets a little more complex and a lot more expensive

Is the engine out of the car?

Edited November 8, 2022 by tech71

[NickVyse]

I've had a head warped enough to make the camshaft bind - did it slide out easily? No point spending money and finding out it's toast when you come to build it back up again.

[Mark92131]

4 hours ago, Summit321 123 said:

I dont think he pressure tested it yet.

 

You would think he would test it for cracks before he began skimming the head.  You should ask him before he skims it another 7 thousands.

 

Mark92131

[Hans]

is the front cover getting cut too? current thinking is to reuse head bolts. 

Per Toby, is block still in car? mileage on motor? You're getting into scope creep territory.

[Summit321 123]

1 hour ago, Mark92131 said:

 

You would think he would test it for cracks before he began skimming the head.  You should ask him before he skims it another 7 thousands.

 

Mark92131

He said it needed to be flat before he could test it. I was already thinking it was a good idea to deck it so I let him go ahead. I am interested in the table of limits he was looking at because according to the image above his action is beyond limits. 

Summit

[Hans]

And the front cover? It needs to be done with the head!

[Summit321 123]

5 hours ago, NickVyse said:

I've had a head warped enough to make the camshaft bind - did it slide out easily? No point spending money and finding out it's toast when you come to build it back up again.

I hadn't thought of that. I wasn't looking for binding or anything when I removed the cam but it seemed to slide out fine. Would that in turn cause out of round of the camshaft? Is it worth putting a dial indicator on it. 

[Summit321 123]

Just now, Hans said:

And the front cover? It needs to be done with the head!

Yup I left it with the head and it't hardware.

[Summit321 123]

2 hours ago, Hans said:

is the front cover getting cut too? current thinking is to reuse head bolts. 

Per Toby, is block still in car? mileage on motor? You're getting into scope creep territory.

Mileage is 65k. Block is still in I would've taken it out by now but I just bolted up the transmission for some work back there. I am trying not to go off the rails but rings are relativly inexpensive and I dont know when I'll have it broken down to this point again.  

[TobyB]

If you didn't notice binding when the cam came out, you're probably OK.

They have to be noticeably stiff to cause problems, and you'd have remembered that.

 

Total cut of 0.022" isn't too bad- that puts you just a little over the 'limit' of 0.50mm, and that's not

a hard limit.  Add 0.30mm back with the 1.80mm head gasket, and you'll be sportingly fine.

 

The danger with the rings is that you'll measure the ring lands, find that they're a bit too worn,

then you'll be into pistons, and at that point a block bore, and hoo boy!  fresh engine time!

I freely admit that when I have a 'clean it up and run it' engine, I refuse to measure the ring lands

because I just don't want to know.  Then, when it breaks a piston crown, munches a ring, and trashes

the head, I can just shake my head and say 'jeeze, I guess I know how THAT mess could have been avoided.'

Whereas, if you JUST do the top end, the worn rings will burn TONS of oil before anything goes bad,

and you'll probably build something to replace it before it grenades.

 

see how this goes???

 

heh

 

t

 

[Lorin]

^ Truth !