porksboy Dork
5/14/09 7:24 p.m.

O.K. they dont have to be old school phenolic ( too expensive from McMaste-Carr) but I need to make some carb spacers and I thought I oughta just make them insulators to keep engine heat away from the carbs also. So what can I make them from that will stand the heat of a push rod with the exhaust and intake on the same side of the head? About 1/2" thick (not critical) and cheap (prefer free).

Trans_Maro Reader
5/14/09 7:47 p.m.

Someone will probably tell me it won't work but I know better.

Plywood sealed up with polyester resin. Cheap cheap and you can simply add a sheet aluminum heat shield to the bottom of it.


TJ Reader
5/14/09 7:48 p.m.

I bet if you specify your engine and carb(s) someone on here will have what you need sitting around in the garage gathering dust.

I'm interested to see what ideas people can come up with on this one.

93gsxturbo Reader
5/14/09 7:59 p.m.

Plywood works well.

erohslc New Reader
5/14/09 10:14 p.m.

I googled "surplus phenolic"


Pretty cheap here, but $250 minimum: So find a couple of friends to share the costs.

Or find another place (are you near Skycraft?)


porksboy Dork
5/14/09 10:44 p.m.

Ah Sky Craft. I went to school 2 blocks from there. Only problem was i had NO $$ to spend then. Thank god looking was free. I did pick up small pliers and o-rings to use as belts on my lathe.

There has to be a similar place in Atlanta, I just havent found one.

I thought about plywood, didnt think about sealing it with resin. It would be easy to make. I just dont want to do it again and again when they crap out.

The spacers are for 1 1/2" SU carbs. I dont think the angle pf them makes a diff but they are straight in and on a Spitfire 1500. I dont HAVE to put them on but it only makes sense to do so.

44Dwarf Reader
5/15/09 6:24 a.m.

Use paper gaskets and Stainless steel sheet or alum sheets layered. If using alum cut the OD larger to acts as a fin.

Tim Baxter
Tim Baxter Online Editor
5/15/09 6:25 a.m.

God, those things are common as dirt in late Midget/Spit circles. Ask around, someone will probably give you some.

John Brown
John Brown GRM+ Memberand SuperDork
5/15/09 6:27 a.m.

Use a quality hardwood.

I have used cured oak for carb adapters more than once.

erohslc New Reader
5/15/09 6:45 a.m.

You probably want something thinner than 1/2", to get as much clearance from the inner fender lip when the bonnet closes. Otherwise, even if the carbs don't foul, getting an air filter to fit can be an issue.

Use the heaviest gasket material that you can find, and cut out a (or several) gaskets to fit, 1/16-1/8" should do.

Or locate a gasket kit from the Euro 1500, that used 1-1/2 SU, ISTR thick fiber spacers for exactly this purpose.

From a heat standpoint, the radiation from the exhaust manifold/header is more of a concern anyway, as boiling fuel in the external float bowls is common. A simple aluminum (or even steel) heat shield does a great job, There was a thread recently on a different list that posted a cad file for the shield, don't have time right now to chase it down, but I can fetch it this evening.


Jensenman SuperDork
5/15/09 6:52 a.m.

Lots of Carter, Holley and Motorcraft one barrel downdrafts on various 4 and 6 cylinder engines had a thick gasket with two plastic rings to control the compression, they make good heat insulators. I have used them on MGB SUs before when converting a single Stromberg to twin SUs, the original thick spacers didn't allow enough room between the carbs and the brake booster.

I have also seen heat insulators made by cutting out aluminum plates the same shape and size as the carburetor mount gasket and then stack gasket-plate-gasket-plate-gasket-plate-gasket.

Heat from the exhaust boiling the fuel in the bowl is a very real concern. The good thing is that heat shields are easily made from aluminum sheet.

spitfirebill HalfDork
5/15/09 8:09 a.m.

Stange this would come up, but I need the same thing, spacers for HS4 carbs on a twin carb intake conversion on a Spitfire. Should be the same ones that go on the early MGB. Anybody have any extras? I do know that I can get Baltic plywood at Hobby Lobby and that may be my answer.

jamscal HalfDork
5/15/09 9:48 a.m.

I've got a drop of phelonic material. 7x20x1/2

$20 shipped. (just covering the shipping and trouble).

It's the brown looking stuff and I can get a pic if you're interested.


porksboy Dork
5/15/09 7:02 p.m.

jamscal, you have a P/M.

This is one of the things that makes the board great.

spitfirebill Dork
10/27/09 2:31 p.m.

Well I found the real thick phenolic spacers off an MGB to use on my Spitfire twin HS4 conversion. I suspect they will be too thick to use. Can I just cut them in half?

erohslc Reader
10/27/09 8:50 p.m.

In reply to spitfirebill: Just use some pieces of 1/16" circuit board. Fiberglass/epoxy or phenolic are both available for pennies. Easy to cut and fab with common hand tools (but use a dust mask).


pitbull113 New Reader
10/27/09 9:04 p.m.

kitchen type plastic cutting board?

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