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Discussion Starter #1 (Edited)
Education needed on copper head gaskets. I have a 468 Bullit roller motor in a Mantra Performer. Eagle crank/rods. J/E pistons. Dart Pro 1 aluminum heads. Being a lake boat will be its only purpose. This is my first engine to own with copper head gaskets. Don`t know much of its history except that an idiot with more money than brains previously owned it. He didn`t run a dipstick so i`m pulling the oil pan to check the bearings etc. The dipstick hole is plugged with silicone. I can see on a tab sticking into the lifter valley that says 4.370 and .040 . Heres my questions; does running a copper gasket automaticly mean that it would have to been o`ringed? Dependable without water getting into the oil? I don`t know whether to go ahead and try it or not. I can see where a small amount of orange silicone has squished out all around the head. I believe the block has already been decked by looking at the right front of block where the number should be. How deep are o`ring grooves usually cut? If only the heads are ringed maybe i could have them shaved. I`m thinking i`d be safer with fel-pro 1017 gaskets. Or would i? Thanks in advance for any info.
 

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1017 Felpros

Until you know "if", and "where" the heads/block are "O ringed" you can't make a gasket decision... The Felpro "bore" seal isn't round and quite often doesn't conform to o rings that may be...(Unless the ring grooves were cut on a CNC type mill they will be cut round).... I will say, "If it aint broke, don't fix it"....
Ray
 

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mo balls than $cents$
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Im with ray.if you have to change them go with titans ics if blocked isnt oringed, they have a nice firering setup and sealing around the coolant passages.can be bought 120 a pair from good vibrations.coppercoat em good and lay em on.most copper hgaskets have a round chamber so measure widest points of head chamber prior to ordering the correct bore gaskets.

richard whats a mantra performer look like? Is that what my hull is called? 16ft mantra tunnel
 

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mo balls than $cents$
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Tom, a Mantra Performer is a winger
Oh ok thanx dave.i wet sanded SBT off under he mantra on the transom, thot thats what they were called maybe? I know richard like the lil tunnels so thot maybe he bought one.im gna just tell everyone its a Short Badass Tunnel lol
 

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Discussion Starter #6
I`ve still got the Texas Tunnels. The performer is shaped like the TX-19 but narrower and probably not near as safe. It was built by Greg High from a Mantra mold in 93. Bought it over a year ago and haven`t been to the lake in it yet. I robbed two 1050`s and a Comp belt drive off it for the tunnel hull. It was supposed to be Eagle crank & rods with J/E pistons. The crank is there but the rods are steel I beams with 7/16 bolts. No J/E pistons either. The cam is 311/315 276/284 731/731 . The pistons have a black coating on the skirts and i can see an image on their side on BDC but not enough to read. Here goes another set of questions; What brand piston is black like that? Are the copper gaskets reusable? Do they torque the same as a Fel-pro type? Help.
 

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steelcomp was here
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Ditch the copper gaskets and run Cometics or Felpros, don't worry about the o-ring grooves. I've had several engines that ran with no o-ring wire. One with Cometics and the others with Felpro composite. On one 467 (12.5:1, 820hp), the fire ring had crossed over the o-ring groove. NO problem, no leak, no loss of compression. When I took the gasket off and looked at it, it had printed nicely into the groove and there was a little sign of combustion in the groove but big deal. If the groove is sealed, it (combustion pressure) can't go anywhere. I know some guys intentionally ran grooves in the block with no wire to help hold the gasket in place. Gave the gasket something to bite into.
 

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Copper gaskets come in different thickness.If the block has been decked.The pistons may have been to high in the hole .So they may used a thicker gasket.Something to think about.
 

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Discussion Starter #9
I thank all of you gentlemen very much for the info. :thumb: The gaskets will go to the scrap copper pile and 1017`s it will be. Knowing that a possible o-ring won`t cause a problem has paved my path. Thats the shove that i needed.
 

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Copper gaskets come in different thickness. If the block has been decked. The pistons may have been to high in the hole .So they may used a thicker gasket. Something to think about.
The current copper gasket is marked as a 4.370 bore/.040 thick gasket. A .039/.040 Felpro should be fine.
I thank all of you gentlemen very much for the info. :thumb: The gaskets will go to the scrap copper pile and 1017`s it will be. Knowing that a possible o-ring won`t cause a problem has paved my path. Thats the shove that i needed.
Like Steel said, Felpro and Cometics are used on O ringed blocks without O rings all the time with no issues. Copper gaskets even with O rings on a N/A or mild boosted is insane. Its a throw back to the days of layered asbestos and steel gaskets. I'd hate to tell you how hard I abused Felpro performance head gaskets before moving to Cometics, and still do not use O ring copper.

By the way, the heads were not happy with those 4.370 bore gaskets. They would be even less happy with Felpro 1037 and have a potential sealing problem with the fire ring in the chamber. Use the 1017.



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How much larger, than the engine bore, can the gasket bore be before is causes a problem ?
The gasket being larger than the bore does not cause a problem other than an un-necessary loss of compression and a small area where un-burnt gas can be trapped. It's really of no consequence.
 
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