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Dumb carb question

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tahoe healey

tahoe healey

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Are the spacers necessary on the HD8 / Bj8 carbs? It would be a whole lot easier to remove the air filters with them. Perhaps a thinner version?
 
To say necessary leads to why they are there and would be your call to leave them off. They reduce heat transfer as not to boil fuel in float bowl one. Two Air fuel mixing takes time as not to flood cyl, That being said even mixture flow into manifold race cars port and polish same, cylinder valves have seats with three cut for more rounded fuel entry and even spread for better burn that leads to more power per firing. For the few times air filters are removed I would say keep them or a fire EX close. I would leave this open for more Threads Madflyer
 
tahoe healey said:
Are the spacers necessary on the HD8 / Bj8 carbs? It would be a whole lot easier to remove the air filters with them. Perhaps a thinner version?
Click to expand...

The factory thought them necessary. But they didn't live in the mountains and have to run ethanol gas. So maybe the situation has changed.

Jags used a thinner one - around 3/16" - you can get them from Joe Curto or Moss.
 
Very interesting replies:

However:

I been in the mountains , valleys N snow in Colorado but nevah had any trouble from them fellas so I just let them alone.
 
My problem is not getting them off (well, yes, that is a problem). The problem is getting the Uni-Syn seated on the carb so I can see the float height.
 
That is what I usually use but I figured I'd do a more complete adjustment as I am going on Dave Nock's famous Fall Colors/Passes tour nest week. Some passes are over 10,000 feet from a start at sea level. Then next May many of us are headed your way for Conclave in Big Bear, CA. That will be another a couple of thousand miles.
 
Relating to spacers, what is the correct material for the heat shield to insulating block and heat shield to carburetor.

Moss lists 4 gaskets to use, all same part number, no description of the material.

I have a collection of an aluminum and an orange-ish hard gasket. I have another two that are thinner and more flexible, one is pinkish says SU, the other is solid gray.

DSC02408.jpg
 
The grey ones are what Moss shows on their website. They imply that the order is manifold, phenolic spacer, gasket, heat shield, gasket, carburetor. The gaskets are paper.
 
Thanks John.
The paper gaskets being correct, noticed both have the same shape. The aluminum and orange ones have a different shape.

What would the aluminum and orange-ish spacers be used for?

Steve, I see an imprint on your HD8 phenolic spacer that looks like there was an aluminum gasket spacer, like the one in my photo.
Is there a gasket between the inlet manifold and the phenolic spacer? (Moss doesn't show one.) Should it an aluminum spacer?
 
steveg said:
IMO the wire pointers are best - they're like a built-in uni-syn without having to remove the air cleaners.
Click to expand...


Yeah Steve:

That's the best way to go for that test
 
AUSMHLY said:
Thanks John.

The paper gaskets being correct, noticed both have the same shape. The aluminum and orange ones have a different shape.

What would the aluminum and orange-ish spacers be used for?

Steve, I see an imprint on your HD8 phenolic spacer that represent the same as the aluminum gasket spacers in my photos.
Is there suppose to be a gasket between the inlet manifold and the phenolic spacer? Is it an aluminum spacer?
Click to expand...

All I ever used are the gray cardboard ones from Moss:

screenshot.2473.jpg


I'm using three of these on each carb on my DMD manifold. Also shown is the thin Jag spacer. The stock Healey spacers made my front carb dome extend under the fender so I couldn't remove it.

screenshot.2474.jpg


Guessing your aluminum ones went between the manifold and heat shield.
 
Last edited:
John Turney said:
The grey ones are what Moss shows on their website. They imply that the order is manifold, phenolic spacer, gasket, heat shield, gasket, carburetor. The gaskets are paper.
Click to expand...


I'm just guessing, but you might not get a good seal between the aluminium manifold and the (hard) phenolic/bakelite spacer without a gasket. I like to use the metal-faced gasket against a hot surface; e.g. the manifold.
 
John Turney said:
The grey ones are what Moss shows on their website. They imply that the order is manifold, phenolic spacer, gasket, heat shield, gasket, carburetor. The gaskets are paper.
Click to expand...

Anderson Moment, p. 157, shows the heat shield to be outboard of the phenolic spacers. Can't tell, but assume there's a gasket between the manifold and spacer.
 
On my car, which is guaranteed to not be stock, but has an original BJ8 intake manifold, there is a paper gasket between the manifold and spacer, in addition to the ones on either side of the heat shield.
 
Phenolic spacers yes, but my BJ7 appears to be equipped with a series of 4 or 5, 1/16 - 1/8 inch stacked asbestos spacers. There are two of them, one separating manifold to heat-shield and the other heat-shield to carb. Gaskets I make myself.
 
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