"Icing" Help?

[Duncwarw]

All,

Since Colin talked me into removing the "header wrap" from my heat exchangers, I was thinking I might put it to use on the intake manifold.

Has anybody done this?

Yes, it's a progressive and I understand it was a poor choice in a carb, but like everything else, hindsight is 20/20. I know this carb came on a few American cars in the past and the car manufacturers installed electric "pre heater" base plates under the carb to combat the problem.

So, if I wrap the intake in an attempt to insulate it, and get lucky in the boneyard with a pre-heater, things have to get better right

TIA

[1979westie]

Wish I could help you my man, but alas, i am a FI Guy. Had a carb on my bug, but of course, it had the heat riser tubes on the manifold.
Eric
_________________
Your car may do 0-60 in under 5 seconds, but can it sleep 4 and cook a meal?

1979 Deluxe Campmobile (quickly rusting away)
33K miles when bought, now at 61K
Proud Member #2 SBS (Stock Bus Society)

[Duncwarw]

Hi Eric,

Eventually, I think FI will be the way to go. All I need is to gain some confidence that this thing will last a while and some money.

Oh yeah, and the energy to do the work

Paul

[Amskeptic]

You want energy to do the work? Come to Massachusetts and stand out in the cold rain until you are shivering in the damp driving mists of truck tire spray. As your shivering gets more violent, pick up your tools and perform "tasks", you'll find energy. . .
Colin
_________________
www.itinerant-air-cooled.com

[Duncwarw]

Quick, somebody hand Colin a diet Coke!

Perhaps a little early in the day for you to put down the coffee, but it reads like an emergency

It's not much better here at home, drizzle, grey and 54 currently.
That's why I'm welding outside and POR-ing inside.

I'd say we got lucky on your visit here, 72 and sunny.
My Guinea fowl seemed to like you and the goats learned that it's better to be a goat than to re-assemble greasy CV joints.

See ya,

Dr. Doolittle (no jokes please )

[Type4parts]

From the FI Swap Post

To use a single carb. I have used the Weber.
There are a few steps that really can help.
Remove the intake tubes and coat the outside of the runners with Dip It . Do it twice so tha you have a nice thick coat.
Do not coat the head to maifold sealing area , the stud area or where the rubber couplers slide on.
This will insulate the runnuers.
Make sure you use the Steel bracket from the case to the base of the center mainfold.
Find a Pinto air cleaner that has the hot air on the snorkle, attach the tube from the tin behind #1 to it.
Find a base carb heater from a 1983 Blazer 2.8 this part goes between the carb and tha cenper manifold.
by doing these steps you will have much better drivabilty when it is Cold.

[Duncwarw]

Now that's EXACTLY what I was looking for.

Responses like that are what sharing on the web are all about.

Thank you "T4P"!

Paul

[Zeen]

[Type4parts]

The reason I insulate the tubes is to keep the heat from the heads transfering up the intake tubes not to keep ice from forming on the outside.

[Zeen]

[Type4parts]

Well I feel that by keeping the Tube as warm as possible the air fuel will stay atomized thru the runners.

[Zeen]

Oh, I get it. The conductive heat transfer directly through the metal in the tubes from the heads, and then insulating to keep from losing it to the air. I would think the air around the tubes (directly over the heads) would warm up pretty quickly, but in the absence of an experiment, I'll defer to your experience.

Don

[Type4parts]

The tubes get the conductive heat.
If you feel the bare tubes after the engine has warmed up they are warm for about the first 6 to 8 inches from the heads beyond that they are cold to the touch.

[Duncwarw]

"Adiabatic", I like that. I think I'll try using it some time.

It is interesting and helpful to know why it happens. When Colin was here, we were talking about the icing thing and you're right, even with the engine, and by extension the surrounding air warm, the intake is cold to the touch.

Great suggestions all around. I'll make a junk-yard run in search of that "hot plate" soon.

Paul

[DurocShark]

Yep. Even in warm weather the intake runners closest to the carb will be cool to the touch.

Air going through the venturi is compressed for that fraction of a second and then suddenly expands once it passes the restriction. Just like an aerosol can, sudden expansion of a gas drastically lowers the temperature.

So those long intake runners are a constant battle between the cold suddenly expanding air and the conductive heat from the heads.

This is why single carbs suck ass in cold weather. The duals on my bus are a signifigant improvement. FI would be even better.
_________________
No boom today. Boom tomorrow. There's always a boom tomorrow.

[Duncwarw]

Yeah, it was a bad choice.

I have a set of Del Ortos in the closet with about ten miles on them.
Unfortunately, they sat around long enough to seize up and it's going to take some work to get them right again but I suspect it'll be worth it if I can ever find the time.

Thanks for the description. It reminds me of a thing I saw on TV once. They had these scientist looking into why there's that little cloud when you first open a bottle of beer. They found that when the outside air hit the beer, there was an instantaneous temperature drop to something like -450. Talk about a nice, cold beer!

[VWBusMan1]

the Weber progressive that is. The PO's mechanic, if you can call him that, removed the FI and put the carb on my '79. Probably worked ok in CA but not so in the damp East. Anyway, after buying all the Pinto stuff with vacuum/temp valves, I just got a metal school lunchbox, put a rectangular filter in it and ran a hose from my heater box. Hose off in summer, otherwise I leave it on. Makes for a slow warm up but otherwise it runs much better. Hence, you should be able to do all this for about $25. Less if your kid won't miss his lunch box And, that way you get to enjoy the sound of a carb.