Paper or metal gasket on dp intake to head?

[ruckman101]

My dim memory recalls that the metal gaskets can be prone to vacuum leaks, thus some recommend a paper gasket, even with permatex on both sides.

And there is a school of thought that is concerned that the paper gaskets dissipate heat differently, even acting as in insulator, thus the heads would run hotter.

Used the metal ones on the last build and didn't seem to have any troubles.

What are folks' thoughts?

And why is there no torque spec for the bolts securing the manifold to the heads?


over-thinking again,
neal

[RSorak 71Westy]

I'd go with the metal, need that heat in the runners.

[vdubyah73]

oops. metal gaskets. can make out of gasket paper in a pinch.

[Amskeptic]

My dim memory recalls that the metal gaskets can be prone to vacuum leaks, thus some recommend a paper gasket, even with permatex on both sides.

And there is a school of thought that is concerned that the paper gaskets dissipate heat differently, even acting as in insulator, thus the heads would run hotter.

And why is there no torque spec for the bolts securing the manifold to the heads?

Original factory engineering/machining uses metal gaskets because it is precise.
The million-and-one different indifferently machined aftermarket manifolds rarely are precise enough to work well with the metal gaskets.

Paper *gaskets* do not have a prayer of a chance of affecting or preventing the heat transfer from the heads to the manifolds! Phenolic spacers, on the other hand, can, but please note, they do not serve as heat blocks so much as heat transfer slower downers.
(I used to write so eloquently)

This has nothing to do with making the heads run hotter ?!?!?!?
This has only to do with the heads (heat source) transferring heat to the manifolds. Carbureted engines like heat to be transferred to the manifolds to help keep the gasoline vapor vaporized on its path from the carb(s) to the cylinders.
Colin

[ruckman101]

Thanks folks, metal it is, but no where in the Bentley have I been able to find a torque spec.

All mating surfaces got a good cleaning/sanding/leveling before assembly.

neal

[vdubyah73]

14ft lbs head to manifold, 7 for heat risers. page 86 chapter 5. personaly i go up past 14 but not by much. thought i had posted that. i think this thread was pruned, hense my oops post above. i misread and answered regarding head gaskets. post is gone now.

[ruckman101]

Missed it, thanks.


neal

[Amskeptic]

14ft lbs head to manifold, 7 for heat risers. page 86 chapter 5. personaly i go up past 14 but not by much. thought i had posted that. i think this thread was pruned, hense my oops post above. i misread and answered regarding head gaskets. post is gone now.

I fixed two heads last summer that had pulled intake studs.
When the engine heats up, it provides the final tightening and gasket mating.
Trust the factory figures, Luke.
Coli Wan Kenobi

[vdubyah73]

i've seen too many manifold to head vac leaks on mine and others recently installed intakes. by not much i mean just that, just a couple pounds. using the notoriously inaccurate pointer type torque wrench, i go to 16-17 ft lbs. i dunno, works for me. if using paper i make my own out of bulk gasket material about as thick as pizza box cardboard. learned in the navy you can get away with a piece of cereal box cardboard in a pinch. grease a paper gaskets on both sides and it can be reused a couple times, generally you only have to wipe off sealing surfaces and regrease.