Intake gasket thermal resistance

[induction apprentice]

Would anyone be interested in sharing a gasket material suggestion / source that would offer the best possible thermal resistance as an intake gasket material? I am trying to go away from o-rings on an LS to reduce intake to head surface contact area in an attempt to reduce heat transfer to an aluminum intake manifold.

I would really appreciate any help in this direction.

[mag2555]

Wood or fiberglass sandwiched with. A .010" layer of gasket material on each side, and the thicker the core the better so concider wacking off as much Manifold thickness as you dare to still not have it crack when you bolt it down.
Masonite would work good also, it's just a mess to cut it!

[induction apprentice]

Thank's for your suggestion. I have made spacers in the past sandwiched between gaskets and the flanges milled before. That's actually how this idea got into my head. The problem is. the manifold design / flanges don't lend them selves well to the above and so I was thinking as a lazy option. I might be able to bail on the o-rings and at least find a well insulated gasket. There is enough room on the flanges to mill a little off to accomodate a couple .065 or .083" thick gaskets.

I agree wood is good. I use it under carbs all the time.

Anyways. I am really interested in anyone who might know what the best gasket material with the best thermal insulating properties is and where to get a role of material or what ever they might have?

[twl]

Cork is the best insulating gasket material.

[user-17438]

I have made fabricated manifold plenum spacers out of Delrin and carb spacers out of it as well, and noticed quite a difference in temperature at the top.

The nice thing with Delrin is that it machines well and is resistant to most chemicals.

[user-17438]

Oh and if you are willing to make plastic spacers for the bolts. Remember heat is transfered through the bolt head.

[engineguyBill]

I don't think that the intake gasket material is going to make much, if any, difference in the amount of heat transferred from the cylinder heads to the intake manifold. Your efforts would be better directed at keeping the fuel cool as it enters the intake manifold. Also make sure that air is able to circulate around the intake as best you can.

[Walter R. Malik]

I use UHMW in whatever thickness is needed.

[cjperformance]

Oh and if you are willing to make plastic spacers for the bolts. Remember heat is transfered through the bolt head.

You beat me to it ! This makes an amazing difference

[induction apprentice]

Thank's for all the replies so far. I am not sure how much gaskets on thier own can impede heat transfer from the head to intake. But years ago I put two bags of party ice on an intake manifold on the dyno. And only for about five minutes and although I can't remember the exact number? I think around 20 horsepower showed up. So I am a believer in atleast attempting to prevent heat transfer to the manifold. Gaskets may not be the answer on their own. But making spacers on this configuration is going to be a bugger and I am thinking even if gaskets do nothing. It is so easy to use gaskets instead of o-rings. Why not give it a try. I guess I was thinking in our high tech carbon fiber, nanno fibre kevlar stem cell world today. There would be a magic space shuttle tile gasket material down at the local part store that will stop the Sun. Someone above. I think Malik had a suggestion. I will go have a look at that and any other suggestions would also be greatly appreciated.

Cheers! IA

[user-23911]

Does the manifold have hot water flowing through it?


I've done a few tests myself with intake manifolds and heat soak. With a dry manifold.
Starting off cold, everything is cold........easy.
Drive it, everything gets warm, the IM stays relatively cold until you stop.
Once you stop, the temps all even out.....hot everywhere. Heat soak.


Once you start it up again, there's cold air flowing through the IM.
It cools down again........it's actually air cooled.


Conclusion.........commercially available insulated gaskets are yet another waste of money.
But if you're going to do something silly like a custom stroker with spacers under the headgaskets and spavers in the V for the IM........it's a good idea.

But an IM with hot water in it is another story.
It's always hot.
It's water heated.

[4vpc]

Reinforced phenolic resin is usually used for this job.

[amcenthusiast]

Picture framing 'matboard'.

-best results using what is called 'rag mat'; this type of picture framing matboard is made from purified cotton fiber, as opposed to 'standard picture framing matboard' which is made from wood pulp. (the cotton fiber matboard is more expensive than the wood pulp matboard -about twice the price of regular matboard... like $8 per sheet vs $4)

-typically available in 32" x 40" sheets (1/16" thick)

-when you 'tear it', 'rag mat' appears to made of 'long strand' cotton fiber, as opposed to paper mat obviously showing short strand wood fiber, like paper.

IMO, 'rag mat' is excellent for making any type of custom intake manifold gasket where some 'crush' is desired -it's 'soft' and conforms to variations of surface texture very well, shows less 'bulging' than cork.

-make a 'paper trace' of the desired gasket shape; use masking tape or fog a light coat of 'spray glue' on one side of regular paper to temporarily place it on the flange, rub a 'carpenter's pencil' to mark the outlines, then cut out with X-acto knife.

-then fog on a light coat of spray glue to your paper trace and stick that onto the matboard. Cut your custom gasket with a utility knife having a new sharp blade (or best sharp blade using knife blade sharpening stone) (sharpest blade helps prevent the fibers from 'balling up' as you cut)

*The name 'Fel-Pro', comes from/is a shortened version of the former name of the company that was 'Felt Products Mfg. Co.' as in FELT; cotton fiber (possibly wool?)

Back when their name was 'Felt Products Mfg. Co.' Fel-Pro used to make a gasket cutting kit. The cutters contained in the kit are very similar to leather cutting tools (like heavy duty cookie cutters) -their kit contained sharpened tubes and semi-circles... which I found rather easy to copy, to make my own tools.

http://theamcforum.com/forum/xrv8-greml ... age14.html

I make my own gasket cutter/cookie cutters using scrap pieces of header/tubing -just slice the tube lengthwise and form it to the hole size needed and weld or braze the seam, then sharpen the one end to make your hole cutter 'die', or 'hole puncher'. (use hardwood for a a backing plate, behind the gasket to be punched out)

Link to XRV8 Race Parts custom fabricated AMC 327 Rambler V8 independent runner intake manifold picture album:

https://goo.gl/photos/aYSZrhqms7YNLykZ6

[img]

customintakegaskets.jpg

[/img]

Experimenting with many types of low cost gasket sealers, IMO, a product named "Seals All' works best for any type of gasket that will be exposed to new gasoline/air-fuel vapors. -basically all others turn to goo and make a mess -Seals All works like contact adhesive to hold the gasket in position (not quite as good as 3M weatherstripping adhesive, but that stuff dissolves in gasoline) I'll typically use it on one side of the gasket only, so it can be taken apart without destroying the custom gasket & for ease of servicing the assembly.

Water injection became a popular topic in the mid seventies to help high compression muscle cars deal with low and no lead gas -the water mist helps reduce intake charge temp, and combustion temp, to help avoid detonation... -has a cleaning effect also

Certain AMC cars were made to have their A/C evaporator core drain dribble cold water onto a fluted section of the transmission bellhousing where it would run down onto the exterior of the main case to help cool the transmission gear box...

[induction apprentice]

Does the manifold have hot water flowing through it?


I've done a few tests myself with intake manifolds and heat soak. With a dry manifold.
Starting off cold, everything is cold........easy.
Drive it, everything gets warm, the IM stays relatively cold until you stop.
Once you stop, the temps all even out.....hot everywhere. Heat soak.


Once you start it up again, there's cold air flowing through the IM.
It cools down again........it's actually air cooled.


Conclusion.........commercially available insulated gaskets are yet another waste of money.
But if you're going to do something silly like a custom stroker with spacers under the headgaskets and spavers in the V for the IM........it's a good idea.

But an IM with hot water in it is another story.
It's always hot.
It's water heated.

LS / No water Joe.