HS6 BJ7 Carb Insulators

[BLong63AH]

HS6 BJ7 Carb Insulator Blocks # Needed?

Having to do a little work on my HS6 Carbs and I noticed when ordering a rebuild kit that I have more than 4 total insulator blocks? Catalogs and pics I have seen show 4 total, one, two total, on each side of the heat shield. Is there any possible reason/benefit for having more?

 

[Bob_Spidell]

I think the originals were black phenolic--aka Bakelite--and, as you say, there was one on each side of the heat shield. It almost looks like a PO rolled his own; like there's actually 6 total on each carb, albeit thinner than OEM. If I had to guess I'd say s/he built them up on the manifold side in an attempt to keep the fuel lines from cavitation ('vapor lock') when hot.

 

[steveg]

I think the originals were black phenolic--aka Bakelite--and, as you say, there was one on each side of the heat shield. It almost looks like a PO rolled his own; like there's actually 6 total on each carb, albeit thinner than OEM. If I had to guess I'd say s/he built them up on the manifold side in an attempt to keep the fuel lines from cavitation ('vapor lock') when hot.

Maybe the HS carbs are more prone to vapor lock - hence the BJ7 having more insulators than previous cars. The PO went even better with 6 instead of 4. If this was really necessary, we would have seen it on more cars. Like bigger heatshields on 100s.

 

[BLong63AH]

Thank you both for your responses. Does your car/s have 4 only? I guess I will go back to the original configuration for now unless if I have “vapor lock.” I know this motor was out of a 1980’s full restoration that got caught in a tornado right after the completion. My father bought the car for the motor and he has no idea or does not remember adding insulator blocks.

 

[gonzo]

The number of insulator blocks in the photo is correct for early-build BJ 7s; mine's original with 4 thin insulators stacked from the manifold to heatshield and 2 thin ones stacked from heatshield to carbs. All together the look is cobbled up particularly with whatever was used as sealant between the insulators.

These original insulator blocks look to be made asbestos, so be careful. I recently replaced the stacked insulators with phenolic blocks - 2 sets / carb. This combination allows for the HS 6 carburetors to be positioned correctly on their very long carb studs. GONZO

 

[BLong63AH]

Thank you. I will replace as you did with the new blocks.