Heat Insulating Spacer for Holley / Edelbrock Carbs.

[BusheyTrader]

I was asked at Malvern yesterday about the heat insulating spacer I’d fitted between the Holley Carb and JWR Dual Port Manifold on my 7V8 and where I bought it.

I sourced it on Ebay from these guys.  https://www.ebay.co.uk/itm/322351136901?hash=item4b0da00085:g:rvwAAOSwl9BWKNra

A few weeks ago at a show, after 45 minutes on the motorway and 45 minutes of stop / start crawling into the Gaydon display area on a hot morning, my 7V8 was constantly stumbling as I tried to creep forward.  I reckoned it was heat soak feeding through to the carb, even with the 1/4” laminated type insulated spacer that’s been on it for years.  Possibly due to the E5 unleaded petrol in the tank but I’ve not had this issue before.  (Apparently in the hotter states in the US, it’s quite a problem with AFB’s on top of V8’s). The aluminium radiator and electric fan kept the water temperature in check.  On the drive home it wasn’t an issue.

I ordered and fitted the Phenolic spacer a week later and tried to recreate the problem in 33c temperatures.  Motorway runs were followed by parked up sustained idling and  stop / start in 1st gear.  All good. My infra red thermo device failed the day before so I couldn’t take readings.

so if you’re the guy in the smart red DHC with a mohair hood, this is where I got it from and hope this helps.  I’m in no way connected to the seller.

[modelbuilder]

I can confirm your findings, (sorry, I don’t know your name as you don’t tell us). A couple of years ago I had a 7V8 and removed the twin SUs and replaced them with an Edelbrock carb and inlet manifold. I found that even after short runs, if I parked and tried to restart the car after 30 minutes or longer, it took a lot of cranking to get it to start. 
after some research I came to the conclusion that the heat from the inlet manifold was evaporating the fuel in the carb over time. So I rang one of the most popular Rover V8 specialists to enquire about a phenolic spacer only to be told that my theory was incorrect and I should buy a new ignition system from them. I ignored their advice and bought a spacer, end of problem forthwith!  So I can recommend this route if you are having similar problems to Bushy Trader or me.

However, having said all that, my current 7V8 has the same carb but on a low profile Offenhauser/ John Wolfe Racing manifold with just the original thin gasket and I’ve never experienced a problem. 
 

Rodders.