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Discussion Starter · #1 ·
I have one that is leaking water in the motor on a SBF. Anybody got away with just a retorque? Motor has very little run time.
 

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I would try retqing first. If that doesn;t work pull them off and copper spray the heads and deck.
 

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Discussion Starter · #3 ·
Should I loosen the studs and then retorque, or just verify the torque setting and adjust from there? 110 or do you suggest another torque setting.
 

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Was the block and heads decked before you used these gaskets and did you follow Cometics recommended surface finish requirements? I ask only because I just used a set and had to do some surface lapping to get the required surface finish.
 

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Discussion Starter · #5 ·
I hope so. I did not assemble engine. Block was new from Dart so I know it had to be decked. I guess I'll find out if the retorque doesn't work.
 

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Should I loosen the studs and then retorque, or just verify the torque setting and adjust from there? 110 or do you suggest another torque setting.
You have to loosen, then retorque, otherwise the torque wrench will just click. Takes more than they are already torqued, to move them further.
My friends blown SB Ford would not seal up until we hit them with 135 ft lbs. I know this is past the recommened torque but it is working on his motor and the first time the heads have stayed fully sealed up after a few passes at full boost.
 

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mowtown block sbc (copper head gaskets)
run thru several heat cycles let it cool ALL the way down...overnight... loosen them all and retorque to 100ftlbs..good to go then.
 

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Discussion Starter · #8 ·
Well no go on the retorque. In fact gasket is blown between ALL cylinders. I cant even imagine how this happened. I haven't even leaned on this motor at all. Should I try another set of Cometics or go another route. It still is a mystery to me how I can have cranking compression of 220 with the gasket blown between the cylinders.
 

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Well I need picture of the surface finish quality on the heads and block and I could recomend a better gasket if they have one for it.
 

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Well I need picture of the surface finish quality on the heads and block and I could recomend a better gasket if they have one for it.

That is most important with cometic's. I know on the LSx stuff we always use a sealer(GM or other) so the head plugs and gaskets don't leak but it sounds like you are far beyound that.
 

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Two things are needed for proper head gasket sealing, Flatness and Surface finish. The block/head surface requirements for either a Cometics or Felpro MSL type head gasket are pretty strick and would require whom ever machined them to take some care and inspection equipment that is not normally found in one of the local machine shops.
 

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Discussion Starter · #14 ·
The deck and head are smooth to the touch and I put a straight edge on the block and heads and I dont see anyplace that looks warped.
 

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I am not trying to insult anyone but let me share my 31 years of mechanical engineering/shop hands on machine tool building experience.
When a block or head is machined either by milling with a CBN fly cutter or machined on a grinder, if the head of the machine is in perfect tram ( perpendicular to the machining surface) you would see a cross hatch pattern where the cutter or grinding wheel cuts both when it enters and leaves the surface being machined.
If you look at the pictures, what shows up pretty clearly, is a single spiral arc it would indicate that the head of the machine was not in tram which will cause the surface of what ever you are machining to be dished. How much that dish is depends on how far out of tram the machine head is.
Also, Cometics and/or FelPro I believe require a max of a Ra 50 surface finish, in which case you should NOT see any spiral tool marks, instead you should have a very smooth uniform surface.
If you look at past thread on here, head gasket failure is way too common. Biggest problem I see is most engine machine shops do not have the equipment to machine or check a block deck, or cylinder head surface to the requirements that today’s MSL type of head gaskets requirements.

I carry a very large spoon,, how else will I stir the pot?
 

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the surfaces are way to rough and If I had to geuss they look like they got cut on the old vulcan machine.

The exhuast valves are black. Sure fire sign the motor is way to fat.

There are signs of light detonation in the speckling on the piston surface. Could be from being to fat and or to much timming.

All that being siad.

Find someone who has a really good head and block decking machine. Get everything cleaned up and get the RA as fine as you can. You cannot make it to smooth period.

Also look at your tuneup. Something is not right there.

Yes FelPro has a nice SBC MLS gasket. Buy a pair fix the machining problems and you will be good to go.


Some Pics







 

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Discussion Starter · #18 ·
Its hard too see in the bics put that speckling on the piston is some form of oxidation. Likes like white powder. I did have some 7530 issues earlier that may have contributed to my problem. I run a big shot plate 71 square with 6lbs flowing. Heads are being machined now by a place that claims to have what I need to run Cometics.

So I should tear the motor down and have the block done also.

Might as well at this point. Too hot here to do anything.
 

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a good tear down with signs of detonation is a good idea. You should be checking for bearing damage since it may have pounded itself a bit. Yes get the deck machined.

Before you mill the heads get me a picture of the mill they are using. Certian machine are totally incapable of producing the finish you need.


Its hard too see in the bics put that speckling on the piston is some form of oxidation. Likes like white powder. I did have some 7530 issues earlier that may have contributed to my problem. I run a big shot plate 71 square with 6lbs flowing. Heads are being machined now by a place that claims to have what I need to run Cometics.

So I should tear the motor down and have the block done also.

Might as well at this point. Too hot here to do anything.
 

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Slocoupe, ask who ever you get to deck the block and heads what they have to check the surface finish with.
Collinsautomotive, I think you and I are on the same page, way too many head gasket failures due to really bad surface finishes.
 
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