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Technical Forums => Shovel Head => Topic started by: billbuilds on June 08, 2019, 04:05:03 AM

Title: CV carb insulator block
Post by: billbuilds on June 08, 2019, 04:05:03 AM
     Do you feel that it's necessary to use an insulator block between the CV carb body and the intake manifold? Ran an SU eliminator for a while w/o one and it worked fine. Not the same animal, I know. Your thoughts please. Bill
Title: Re: CV carb insulator block
Post by: JW113 on June 08, 2019, 08:56:50 AM
I use one, but mainly to get some clearance between the air cleaner backplate and the tank. I have a nice scar in the paint on the tank from not using one.

-JW
Title: Re: CV carb insulator block
Post by: billbuilds on June 08, 2019, 01:01:44 PM
       Thanks JW.  I should have mentioned that it's going on a 73 FX with the stock turtle tank so clearing it should not be an issue. I guess I was thinking more in the realm of any benefit from the thermal insulation that your carb gets using the block versus not using it and just the gasket. .  Bill
Title: Re: CV carb insulator block
Post by: JW113 on June 08, 2019, 01:28:03 PM
How are you mounting it? Rubber flange adapter or press on/JB Weld adapter from Killer? Also, is your intake manifold the compliance bands, or O-ring type?

-JW
Title: Re: CV carb insulator block
Post by: billbuilds on June 09, 2019, 05:53:27 PM
Quote from: JW113 on June 08, 2019, 01:28:03 PM
How are you mounting it? Rubber flange adapter or press on/JB Weld adapter from Killer? Also, is your intake manifold the compliance bands, or O-ring type?

-JW

     I've got one of the JB weld-on adapters. The motor is a 1980 80" so it's got the rubber band style intake seals. SE backing plate has a couple of holes already drilled; will be making brackets to attach to rocker boxes undersides. 
Title: Re: CV carb insulator block
Post by: JW113 on June 09, 2019, 09:48:53 PM
OK, cool. (no pun intended!) I think the main point of the insulator block is to keep the carb from boiling the gas in the bowl when you shut the motor down. If the carb/intake manifold is not in direct contact with the heads, then you don't get the heat transfer to the carb. Stock Evos have the carb isolated with that rubber O-ring spiggot mount. If you're using the compliance fittings on the intake manifold, probably be OK to not head soak the carb.

-JW
Title: Re: CV carb insulator block
Post by: 76shuvlinoff on June 10, 2019, 02:58:43 AM
Using the J&B CV adapter here too. I  do not have a block to speak of like the 3/8 I had with the S&S E, but I do have a thin homemade gasket in there so I guess there's some insulation going on.
Title: Re: CV carb insulator block
Post by: Burnout on June 10, 2019, 09:53:36 AM
I think the insulation block is more for when you park the bike, than running.....

That would slow down heat transfer on a hot soak.
Title: Re: CV carb insulator block
Post by: dirtymike on June 10, 2019, 11:06:06 AM
Isolation or insulation, Which one. 
Title: Re: CV carb insulator block
Post by: Burnout on June 10, 2019, 01:36:42 PM
I think we are talking about the 3/8" insulator that is often found with an S&S carb
Title: Re: CV carb insulator block
Post by: JW113 on June 10, 2019, 03:34:25 PM
Yep, for parked after riding so it is easier to start again (prevent flooding).

-JW
Title: Re: CV carb insulator block
Post by: 76shuvlinoff on June 11, 2019, 02:42:44 AM
 Kinda OT but insulating the fuel line, and/or being very specific with routing, matters on my 76.
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