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914World.com _ 914World Garage _ Carb Insulating Gaskets

Posted by: HarveyH Mar 14 2011, 06:29 AM

I'm getting ready to do a clean and kit on my 40IDF's this Spring and a question came up. I seem to remember talk about using insulating spacers for mounting. There doesn't appear to be anything like this on my current setup.
Do these go between the carb and the manifold or between the manifold and the cylinder head? (2.0L heads)

Who sells them? Part #?

Correct mounting gasket - insulator - gasket?

Currently a few threads exposed at the carb to manifold mount and the manifold to head mount. Will I need longer studs?

I've tried a few search criteria but didn't seem to get the right wording...

Thanks,
Harvey

Posted by: Vacca Rabite Mar 14 2011, 07:53 AM

Yeah, you want to use phenolic spacers to keep the head heat from moving up the throttle body into the carb. make sure that you polish the base of the manifolds with 400 grit sandpaper over glass. You will be amazed at how poorly they are cast, and those flaws will all be air leaks if you don't mill them down.

You will probably need longer studs. I did. I just made them from a length of m8 threaded rod. Real easy.

Zach

Posted by: curt914 Mar 14 2011, 08:51 AM

Hello

I believe what you are looking for are the thick phenolic (like) gaskets that go between the cylander head and the base of the intake manifold.

I got mine at Pelican parts recently, others may also sell them.

Here is the link for a 73 to 76 part.

http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=039-129-707-M17&catalog_description=Intake%20Manifold%20Gasket%20%28%32%20per%20car%2C%20sold%20individually%29%2C%20%39%31%34%20%32%2E%30%20%28%31%39%37%33%2D%37%36%29%2C%20Each%20%20

Be prepared to take Zack's advise with regards to making flat the bottom of the intake manifolds. A good straight edge across the mounting area of the manifold shows the problem.
The gaskets you are asking about are thick, made out of a phenolic kind of material and wont conform to the irregularities in flatness your manifolds might exhibit. In other words, they dont squish!

I have not actually mounted mine yet and at this moment I do not recall what kind of gasket goop (if any) you are supposed to use. Maybe Zach or others might chime in here on that one.
Im doing mine this spring also. But I did see first hand the manifold flatness problem back when I rebuilt my carbs.

Also, the carb experts (Mark Harney, John at Aircooled.net) over on Samba related that many of us seem to apply way way too much tightening torque to the manifold bolts.
I wish Id written that torque value down when I came across that nugget of info. I'll have to search for it again over there at some point. Maybe its just the same torque that the FI manifold gets, I dont know.

Anyway, have fun.

Curt

Posted by: mskala Mar 14 2011, 09:28 AM

I use gaskets on both sides of the phenolic spacers.

Posted by: HarveyH Mar 14 2011, 09:57 AM

Thanks,
Harvey

Posted by: Vacca Rabite Mar 14 2011, 10:04 AM

I used a VERY thin skim of gasket sealant between the phenolic block and the head, and nothing between the spacer and the manifold. At the time, someone had said that was a better option then using a rubber gasket between the head and the spacer. if you sand down the manifold flange so that it is FLAT and SMOOTH you don't need another gasket or sealant between the phenolic block and the manifold.

Zach