Shoptalkforums.com

Since I have recently got a center mount Weber progressive I have been doing some checking on others opinions and knowledge. From what I have read, one of the most common comment was the icing and idle issues due to insufficient heat in the manifold. I will be using the stock manifold heating provision with exhaust tube. In addition to this I have installed some snowmobile grip heaters on the manifold tubes and under the carb. These will be activated by a relay that will be triggered by the coil power. When the manifold is measured to fitment, the heat shrink will be activated and header wrap will be applied to the manifold.

Thinking this may prove to be a solution to the problems I have read about. Depending on weather, I hope to install soon. Will update with results when available.















For what its worth.....

I knew someone had to have done this type of mod before. How well does it work? Any issues with it pulling too much current or getting too hot? Would love to see a pic of it installed with the header wrap as well.


Sent from my iPad using Tapatalk

I don't know how well it will work for you, but one of the keys to success with these 32/36 Webers is following the adjusting sequences exactly. For instance, the idle speed screw must not be turned in to expose the progression hole, adjust prior to install. Mixture screw 1 1/2 turns out from seat to start with prior to install, choke adjusted prior to install. The bench adjustments should make installation and initial run adjusting easier.

I did something vaguely similar on a VW bus with a T4...

I basically packed the area between the block and manifold center section with aluminum foil (pretty solid mass) and wrapped the result with foam insulation tape. The center section also is bolted to the block.

The idea was to conduct heat from the block to the manifold, it helped enough, prevented icing at least.

I also had carb preheat hooked up in winter via a Horizon TC air cleaner. (used ~same carb, I think I actually used that carb as well, have slept since then, that was ~1988ish)

Definitely worth a try - the use of the snowmobile grip heaters seems like a great idea (compared to trying to roll-yer -own from resistance wire).
Years ago we did an oil-heated setup (not a proggy but the principle's the same), by plumbing the full-flow filter via the heatriser pipe. Didn't get warm anywhere near enough to help prevent icing on a cold morning, but it DID eliminate the need to jet the carb pig-rich to make it driveable once warmed up. Hopefully the grip heaters can do better.

Simplest mod I've done to help with the icing was a cut-down coffee can with a freshair hose coupling pipe brazed into it. At first frost in the fall snap it around the (K&N-style) aircleaner and connect a hose to the stock pickup pipe at #2 cylinder head - that starts delivering above-ambient air to the carb within a minute of startup. I made it cover ~270° of the aircleaner so it wouldn't be overly restrictive at high RPM, but you could go for less or more depending upon your climate/specific concerns. Pile's Horizon aircleaner solution sounds much more elegant if there's room under the hood for it.

make sure your exhaust heat riser is like stock....suction side going into your collector....the 2 on aftermarket exhaust do not supply near enough heat