Intake Question - 4bbl upgrade

[MKTSC]

Wow I got 10 with the 4bbl. Polara cop car and the 400/2 Monaco coud get 12-14.

No idea why my economy is so shitty. Recent tuneup, carb rebuilt and working flawlessly, electronic ignition installed.

 

[Xenon]

Heat riser was for the choke to operate. Used heat to control the spring in the choke mechanism. If you run an electric choke it's not needed.

This would be INCORRECT.....
Well, actually,, the first sentence is partially correct...
Choke operation is only a SMALL part for reason of heat riser.....

Electric choke or not on a street car a heat riser is a GOOD thing.......

 

[saylor]

i wont argue about the heat xover passages it was prolly the same engineer that made the exhaust flap valve inside the manifold downtube (...)

, but i WOULD throw that nasty intake into the lake and buy an eddie or weiand top and eddie carb and be done.

if you do use something to plug up those holes - jb weld or whatever - make sure it is resistant to petrol.

try not to die -

- saylor

 

[traintech55]

The divorced (a.k.a. remote) choke closes due to a coiled bimetallic strip that rotates with temperature change. When the engine is cold, the coil acting through the choke connector rod, closes the choke. Contrary to popular belief unit does NOT open the choke (except for the 1937-1938 Delco unit, which never worked anyway, so the statement is still true). External heat to the divorced choke unit caused the coiled bimetallic strip to “relax” or “unwind” removing the closing tension to the choke plate, and allowing the choke plate to be opened by some other means. Early chokes were opened by a counterweight assembly on the choke arm, or by an offset on the choke plate to choke shaft connection, causing the choke plate to fall open when the tension was relaxed. Beginning in the late 1950’s, external choke pulloffs were used. The choke pulloff had a vacuum source attached, which pulled directly against the tension of the bimetallic strip. As the tension relaxed, the choke pulloff would open the choke plate.




Heat riser was for the choke to operate. Used heat to control the spring in the choke mechanism. If you run an electric choke it's not needed.

I GUESS YOU DID NOT READ MY POST ABOUT THIS. THIS IS NOT FOR THE OPERATION OF THE CHOKE. IT IS TO KEEP THE FUEL FROM PUDDLING IN THE INTAKE MANIFOLD IN COLD WEATHER.

 

[stubs300]

Yeah it's pretty nasty and I don't want to put that in the engine. You have any tried and true methods of cleaning intake runners?

Just take it to a machine shop and have them dunk it like they do a block. It will come out lookin new! I wouldn't pay more then $50 for that.

 

[livininharrow]

Yes, you can tap and install flush pipe plugs.The holes were for the EGR that you won't be using.Yes I'm old.......

you may be old but not dumb

 

[70bigblockdodge]

Before anyone else chimes in about blocking off the heat riser passages, let me just ask this one question and lets see who is smart enough to answer. If the passages were not needed, why the hell did the engineers we all respect put them in, even on the Hemi.

Cold weather drivability that's why Hemi is only under rear carb.

External heat to the divorced choke unit caused the coiled bimetallic strip to “relax” or “unwind” removing the closing tension to the choke plate, and allowing the choke plate to be opened by some other means

The bimetallic spring and gravity open the choke fully, the pull off opens it slightly upon startup as to not foul the plugs. Electric heater added to divorced unit in 1973 to open choke earlier.

. That TQ is one thirsty mutha.

Yours is leaking from internal crack or bad square o-rings at the main circuit.

No idea why my economy is so shitty. Recent tuneup, carb rebuilt and working flawlessly, electronic ignition installed.

Probably need more ignition timing.

but i WOULD throw that nasty intake into the lake and buy an eddie or weiand top and eddie carb and be done

Except for weight penalty that is a very good intake on par with weiand and Eddy performer the rpm beating it because of runner length.

 

[dart4forte]

If you block the heat riser the divorced choke gets no heat

 

[MKTSC]

If you block the heat riser the divorced choke gets no heat

Not going to block the exhaust crossover, but I am going to plug the two holes directly underneath the carb, as well as the EGR port in the top of the manifold.

Probably need more ignition timing.

When I installed the electronic ignition, I retimed it and advanced the **** out of it.

Except for weight penalty that is a very good intake on par with weiand and Eddy performer the rpm beating it because of runner length.

I had no idea that this intake flowed so well. I have an old Weiand, but I figured it'd be easier to just swap the TQ with the matching manifold. Not worth the additional hassle for a stock 400. Plus I like factory solutions.

 

[70bigblockdodge]

had no idea that this intake flowed so well. I have an old Weiand, but I figured it'd be easier to just swap the TQ with the matching manifold

It has good volume way better than a 67 383 4 bbl intake would have.
8 mpg sounds low for a 2 bbl hope it improves for you with 4 bbl with timing right and health engine poor mpg points toward fuel wash on rings. Of course 8 mpg in a purely around town stop and go is not too unreasonable.

 

[saylor]

Not going to block the exhaust crossover, but I am going to plug the two holes directly underneath the carb, as well as the EGR port in the top of the manifold. ....

OOK now I'm totally confused. the 'two holes directly underneath the carb' is the 2 holes ive been talking about this whole time. and now were talking about an EGR on TOP of the manifold. so whats the 2 rusty lookin holes in the bottom of the plenum again?

help me not die -

- saylor

 

[saylor]

and yes that manifold is good, except for the 2 rusty holes in the bottom of the plenum . . .

 

[RCB]

As far as a good way to clea out carbon, my secret is boiling the whole tthing in water and lemon juice solution. Buy a cheap electric burner and do it outside. Leave it in for at least 30 minutes. Also works great for
Carbs. Make sure to rinse well.

if you don't want to mess with it, take it to a shop and have it hot tanked. It should be less than 35.

 

[max1196]

The two small holes at the bottom of each plenum go to a separate port, which is the inboard of the two ports of the EGR valve, the out board port under the EGR valve is directly into the exhaust crossover port of the manifold. Putting plugs in these two small holes will help stop unwanted fuel from laying in the now deactivated EGR port.
For cleaning, try a 10-1 ratio of muriatic acid and water, soak over night (outdoors) and then a solution of baking soda and water to neutralize the first mix.

 

[MoPar Maniac]

Yours is leaking from internal crack or bad square o-rings at the main circuit.

Well, I dunno about that as it had been rebuilt with all new o rings, etc and no obvious cracks but that was circa 1980 or so. That car is long gone.

 

[Dads300]

There really isn't any need to plug those EGR ports in the intake floor unless you really feel the need. The EGR valve block off plate does that job for you. If any wet fuel does get down inside them, it will boil away once the engine starts to warm up. No different than if the EGR were fully operational. By all means, clean the carbon out of the crossover as well as you can (doesn't need to be spotless). Clean it, paint it, bolt it on.
Travis..

 

[MKTSC]

Sounds like a plan.

Now I just need to find an aircleaner that fits! I want an OEM cleaner from something, don't really want to go aftermarket if I don't have to. I'm picky about aesthetics and I want it to look like it belongs there.

Having a hell of a time on eBay. Anyone know what vehicles definitively came with TQ's that I can source an aircleaner from?

 

[traintech55]

Sounds like a plan.

Now I just need to find an aircleaner that fits! I want an OEM cleaner from something, don't really want to go aftermarket if I don't have to. I'm picky about aesthetics and I want it to look like it belongs there.

Having a hell of a time on eBay. Anyone know what vehicles definitively came with TQ's that I can source an aircleaner from?

The Thermoquad started in 71. They were the same on all 72 and up four barrels until the middle 80's for trucks.

 

[dart4forte]

Sounds like a plan.

Now I just need to find an aircleaner that fits! I want an OEM cleaner from something, don't really want to go aftermarket if I don't have to. I'm picky about aesthetics and I want it to look like it belongs there.

Having a hell of a time on eBay. Anyone know what vehicles definitively came with TQ's that I can source an aircleaner from?

There's one on Moparts for sale

 

[MKTSC]

Link?