Choke tube and heat riser, do I need them?

[Rolf]

As I am disassembling a 348, I am making plans what to do with each part. I am thinking ceramic coating for the stock headers, and that's when the question popped up:

This header came off my 348 4bbl engine. Would the choke tube fit to the center carb on a tri-power? Just holding it up, it seems like it's long enough? Do I need it in the NW?

What about the heat riser on the one exhaust? Will I need it, or should I just eliminate it?

 

[Fathead Racing]

If you live in a cold climate area and plan on picking up the sunday paper in your hot rod you may want to keep the stock choke system, but only if the stock system is in new condition. A better way for the above advise is an electric dhoke installed . I have had both on my 348 with three two's and can tell you that the electric choke is the cat's pajamas. Although my stock choke setup was detailed to new condition the electric setup was by far the better working choke. The heat riser will direct hot exhaust gasses under the intake manifold bypass under the center carb on the three two setup in able to atomize the fuel by heating the intake. I placed stainless steel plates over the bypass, eliminated the riser and replaced the choke with an electric unit. Engine started and ran very well into November weather here in NE Ohio.

 

[Rolf]

Thanks

Yeah, I think you are right, I don't think I need it. It is fairly mild here in the NW as well. Good advice about the elec choke.

Did you find a choke that fit the center carb on the tri-power then? What application did it come from?

Thanks

 

[tripower]

Rolf, I am in the same boat here. In my case the tube has broken off inside the manifold. I've been wondering if I should restore the factory choke setup. I am going to sit back and take all of this in. Thanks for asking the Question. Dan

 

[Fathead Racing]

Yeah, I think you are right, I don't think I need it. It is fairly mild here in the NW as well. Good advice about the elec choke.

Did you find a choke that fit the center carb on the tri-power then? What application did it come from?

Thanks

I'll look through my recipts.

 

[w ogden]

Rolf, got my choke kit from Vintage Speed in Vero Beach, Fl. There are others out there that you can find I'm sure.

 

[Rolf]

Rolf, I am in the same boat here. In my case the tube has broken off inside the manifold. I've been wondering if I should restore the factory choke setup. I am going to sit back and take all of this in. Thanks for asking the Question. Dan

Yes, I was thinking of just plugging the hole. My plans are to do an "era correct" install, bur "cleaner", and I will deburr some things etc...if that makes any sense, so filling the hole would be my choice.

I have a Buick 425 Nailhead motor with tri-power, and one pump with the throttle and she fires right up. I have never even used the choke yet.

Thanks for all the input, fellas...

 

[IgnitionMan]

the choke pass through tube should be sealed from exhaust gasses. If it isn't, then, the manifold itself is eroded to the point of leakage. the tube should begin at the air horn at the top of the carb, with a hard line down to the tube, and then, from its other side, to the choke stove at the choke housing. This way, the choke air is filtered, and isn't contaminated with exhaust gasses that would clog the choke up after some time.

If the tube is damaged inside the manifold, then, either a new manifold that isn't compromised, or replacing the tube in a good manifold is warranted.

As far as any porcelain coatings, I stay away from them on cast iron, steels and aluminum parts. Porcelain is porous, lets moisture pass throujgh it, and then, holds the moistyre beneth it, between the coating, and the metal of the host part. This allows rust to fiorm where it cannot be easily seen, and ultuimately, failure of the part that is coated. I just paint stuff, and constantly check for erosion/cracking. .

 

[tripower]

the choke pass through tube should be sealed from exhaust gasses.

Mine is sealed and the manifold is in great shape. I am going to pull my motor this winter and I thought at that time I would deal with the choke tube.

Rolf, Keep me posted as to what you decide. Can I ask where in WA you are. Dan

 

[Rolf]

I am in Woodinville.

I was thinking about a ceramic coating, just so I would not see the paint burn off and rust, but maybe I have to rethink it. I just want them to look sharp after some use.

Great info, guys.

 

[tripower]

Rolf,I'm thinking ceramic as well. There is a guy in Auburn Brad Gui. I think that is how is name is spelled. I've used him in the past. does nice work and very reasonable. I'll try and find his card. technology coatings or something like that. Dan

 

[IgnitionMan]

tripower, if the tube is in good shape and doesn't leak, and you don't want to use it, just either leave it open, or close it off, either way will function correctly. It is only the really bad ones that leak that are a problem.

 

[bobs409]

I have a Buick 425 Nailhead motor with tri-power, and one pump with the throttle and she fires right up. I have never even used the choke yet.

Rolf, my 409 is the same way. I never needed a choke! This thing starts in 20 degree weather and runs fine without it.

 

[models916]

Resin not ceramic

I use metalic resin on my headers and have had no problems in about 8 years. Stuff like Jet-Hot is resin, not ceramic. Just need a little break in time and then can take all the heat you can give it.

 

[IgnitionMan]

I've never seen a Jet-Hot resin coating, only Jet-Hot ceramic.

 

[models916]

difference in terminology?

i just checked with my guy and he says it is ceramic reinforced metalic resin that he uses. He gives it a lifetime quarantee not to come off or crack. Not sure if Jet Hot is the same product. Jet Hot might be different, I have always heard good things abut the product.

 

[tripower]

IgnitionMan, Mine is closed off. I would like to get restored and working so, I thought when the motor was out would be a good time to deal with it. Thanks for the info. Dan

 

[Rolf]

Rolf,I'm thinking ceramic as well. I've used him in the past. does nice work and very reasonable. I'll try and find his card. technology coatings or something like that. Dan

You are thinking about Performance Coatings, yes, I have used them several times. Top notch guys.

It sounds like the jury is out on what kind of coating we can get away with on cast headers. I will talk to them about it and report back.

They did my lake style headers on my Buick motor:

Of course, I am thinking a cast gray look for the 348.

 

[tripower]

Rolf, Thats it. He did the headers and a bunch of other stuff on my 63' custom cab SWB. Great guy. He has quite an assortment of colors and I think the gray would be the way to got as well. Dan

 

[Thirdyfivepickup]

Rolf, in case you didn't know, the ceramic coatings go on very thin. Covering smooth headers it looks good. Over a cast piece like manifolds, it shows every pit, bump and seam. I sent an intake out for a customer and expected it to come back like it was powdercoated... alas, that didn't happen.

Here is the only picture I could find on the web with a quick search...

http://www.customclassictrucks.com/techarticles/137_0312_cermamic_coating_tech/photo_14.html