Intake Question - 4bbl upgrade
- Thread starter MKTSC
- Start date
MrMoparCHP
Old Man with a Hat
I California we are not as worried about the cold as we are the hot. With todays gas the heat crossover will boil the gas and can cause the car to run bad, particularly on warmer days. Again I'm not a mechanic and I put this in my best layman way.
Alan
Alan
traintech55
Senior Member
I understand why some people do block off the heat riser passage, and yes vapor lock in a carburetor will drive you crazy, but once the fuel enters the intake manifold the heated passage helps keep the fuel suspended in the air. It also stops the fuel from gathering in pockets in the intake. I have rebuilt many engines that had the cylinder bores and rings torn up because fuel washed off the oil.
MKTSC
Member
So I noticed my rebuild kit came with a few thin normal-style paper flange gaskets, and a real thick one probably 1/2" thick. Which one should I use? Guess it'd depend on the actuation of the thermostatic choke rod. 1/2" difference would throw off the operation of the choke...
traintech55
Senior Member
Pictures please
MrMoparCHP
Old Man with a Hat
saylor
Senior Member
im sure there are exceptions, but i THINK factory iron intake was metal to metal, with pookey, no gaskets. i heard that if you swap to an aluminum intake you almost HAVE to use gaskets. also gaskets if you had mill work / facing done.
i DID use the thin gaskets, both sides of the pan, with the weiand intake i put on. and pookey. lots of pookey. no leaks wanted.
try not to die -
- saylor
i DID use the thin gaskets, both sides of the pan, with the weiand intake i put on. and pookey. lots of pookey. no leaks wanted.
try not to die -
- saylor
MKTSC
Member
traintech55
Senior Member
Thanks for the pictures. The thinner gasket was used in early production, the thicker one was used in later to help insulate the carburetor from heat. I would recommend the thicker one and make sure you use studs and nuts with lock washers and not bolts.
MKTSC
Member
Thanks for the info, I'll use the thicker gasket and make sure I get studs that are the appropriate length.
MKTSC
Member
Well, got the manifold all cleaned up. Ground the carbon deposits out of the runners, tapped and plugged the holes, made a blank-off for the EGR, and stoned the gasket surfaces covering them in paste-wax afterwards so they don't oxidize before I get this thing installed. Also bought a new divorced choke, and a valley pan and gaskets from 440 source. Installed the studs and test fit the carb last night, and everything seems to line up well.
Still going through all of the factory adjustments detailed in the rebuild, but so far everything is spot on. Just need to get the high idle circuit dialed in, as the thumb screw that hits the cam steps was adjusted out. After that, just have to find a decent weekend to do the swap.
Still going through all of the factory adjustments detailed in the rebuild, but so far everything is spot on. Just need to get the high idle circuit dialed in, as the thumb screw that hits the cam steps was adjusted out. After that, just have to find a decent weekend to do the swap.
Darter6
Active Member
looking good.
67 Fury with a 400. Currently 2bbl Stromberg. Upgrading to a Thermoquad. I got a Thermoquad manifold, and noticed two ports that go from the exhaust crossover and exit directly under the carb. I made a blank-off plate for the EGR. Can I just tap and plug these holes or do they serve some purpose?
Thanks in advance,
-MK
I vaguely recall that in some years, EGR was routed through the intake and directly into the intake stream of the engine. Is this manifold you've gotten the same year as the engine itself? If these little holes end up in the intake crossover passage, then this is a crude form of EGR.
MKTSC
Member
No the engine, carb, manifold, and car itself are all different years as far as I know. I do know, those two ports connect directly to one half of the EGR port on the right side of the manifold. The other half connects to the crossover tube. With a blank off plate in place, those holes wouldn't get any exhaust flow anyways, so I plugged them.
Does the heat riser valve in the exhaust manifold work? Lots of times they rust shut and that just knocks the crap out of gas mileage and performance. If nobody has torched the valve out of the manifold, lots of penetrating oil, patience and hammer tapping will get you back in business.
traintech55
Senior Member
Mopar used to make a product for that. It was a better rust penatrant thsn P B Blaster. Dont know if you can still get it.
MKTSC
Member
That's a good thought, I'd never considered that. How exactly can I ascertain if it's open or shut?
Dads300
Active Member
Reach down there when it's cold and see if it can be rotated with the counterweight. If it moves freely, and it still have the spring action that closes it when cold, it's most likely fine. If it's stuck, or doesn't spring back when you let go, I'd remove the manifold and deal with it.
Travis..
Travis..
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