2 bbl carb spacer heat dissipator

[Nothing Special]

A couple of better tests today. I stopped for gas and went into a NAPA for brake rotors and pads. Both times the engine was definitely up to temp. And both times it did start without my needing to hold the throttle open, but both times it took quite a bit of cranking. Before it wouldn't start without the throttle being open so it's better. But not perfect. Oh well, it's good enough.

 

[jckkys]

Since you have a PVC nipple in the back of the carb, there's no purpose for the aluminum spacer. It conducts heat you don't want. The Felpro gasket is a reproduction of the Motorcraft 1/4" thick insulating gasket used in early '70s 302s between the carb and the aluminum or cast iron EGR spacer that was very hot from exhaust gas. The thick Felpro/Motorcraft gaskets can be stacked on your '68 intake to whatever height you want. The carb mounting studs are the right length for a 1" spacer. I would use 4 or 5. The plastic inserts at the corners prevent over tightening and the fiber gasket swells to stop leaks.

 

[Nothing Special]

On my carb I'm using a nipple on the right side for the PCV, not at the back. But I don't think that's all that significant and I'm not looking for the aluminum spacer.

The carb mounting studs I have are about 1" too short to work with a 1" thick spacer. They are just long enough to go through the carb flange and leave room for a washer and a nut. But remember they aren't original to a Bronco. They came with the junkyard manifold and carb I bought. I forget what year and vehicle they were supposed to be from.

And the Felpro "gasket" I bought doesn't have plastic inserts at the corners. It looks like it does, but actually the whole thing is hard plastic. It seems like they 3D printed something that looks like a gasket with plastic inserts. But it seems to work OK with an actual gasket on each side of it

 

[lbuch40]

Been driving for a month now, I notice a definite improvement from changing a regular gasket to the Felpro.
The real test wiill come this week when temps get into the 80’s and 90’s.

 

[73azbronco]

I use one of these phenolic spacers and a shield

https://www.summitracing.com/parts/...eVOYCvnQpSJe0pedwC5WgKgGrjYkQ7SBoCblMQAvD_BwE

https://www.ebay.com/itm/1938006143...lzjSImSkv2Ww6y943cWBARK07jD0OuyRoCMR0QAvD_BwE

or this

https://www.amazon.com/Holley-108-7...ocphy=9030174&hvtargid=pla-568429050382&psc=1

Drove my 347 for 300 miles around the 101/202 when it was 105. Purposefully stopped and let it heat soak for 20 minutes. No issue starting up.

 

[jckkys]

It all depends on the year. The OP's profile says he has a '69. so there's no EGR and the heat associated with it. Also, the pre '74 2100s had no PVC nipple on the rear of the carb. So PVC has to go to the spacer.

 

[ntsqd]

My reply to a similar thread: https://classicbroncos.com/forums/threads/carb-heat-soak-ideas.312071/#post-3442832

 

[Rustytruck]

Take a look at your engine compartment and clear any obstructions around the fender well so air flow can be the best it can be. like moving heater hoses on the passenger side. I also put header wrap down the exhaust pipe. I closed up gaps around the radiator. anything you can do to control air flow from the radiator to the firewall and out as best as you can. I ran heat sleeve on the fuel line. I fought it piecemeal for years. when I went to Quadrajet for offroad reasons heat issue all went away. the small center mounted fuel bowl runs much cooler than the ford fuel bowl hanging it the hot air coming directly from the fan. no more vapor locking or flooded hot restarts but the small fuel bowl dries up sitting more than a couple days. so crank crank to start up from cold. it ended all my offroad trips where every time we stopped I had to open the hood to cool off.