Heat Cross-over

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matty mopar

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I am curious about whether or not the heat cross-over in the intake manifold is needed?

Is it a necessity to make sure that the fuel vaporizes, or is it really useless once the car warms up?
What are the advantages to removing it?
I have a stock cast iron manifold on my 440.
 
A New York street driven car needs carburetor heat.
 
I idea is to heat the manifold quickly especially in cold weather help cold drivability - in hot weather it just heats the manifold and incoming charge which robs HP. Mine is blocked off but I never drive it once the temp gets down to 40* and colder
 
A New York street driven car needs carburetor heat.

Well, the car is put away around November every year. It never sees snow, so once the weather starts getting cold the car is put away.

During a regular summer or 70 degree day, how much longer will it take the carb. to properly heat up if I block the cross-over?
 
On a street car like ours that get summertime driving, it heats the fuel and causes hot soak hard starting and also makes a mess of the new paint on your engine. My intake paint is baked to black and with the low profile cast iron intake I do have some hard start problems in hot weather.
 
When I lived in NY I ran with my heat blocked was just fine in the summer in the winter before it got really cold it would hesitate a bit till it got warmed up but you get used to it.
 
Well, the car is put away around November every year. It never sees snow, so once the weather starts getting cold the car is put away.

During a regular summer or 70 degree day, how much longer will it take the carb. to properly heat up if I block the cross-over?

Then block it off. It will probably be fine.
 
A New York street driven car needs carburetor heat.

I agree to a point...I think though it depends on when you break your Mopar OUT for the year and when you put it away...if your like me and basically do October-end of March for storage and just have it out say mid April-Halloween you can probably get away without it...but then again im in Central PA and we are normally about 5-10 degrees warmer than NY...I used to live south of Bufflao so I think late April(in the 60's) till late October(in the 60's-high 50's) you would be fine without it...but I dont think it hurts too much unless your racing it.
 
Well, the car is put away around November every year. It never sees snow, so once the weather starts getting cold the car is put away.

During a regular summer or 70 degree day, how much longer will it take the carb. to properly heat up if I block the cross-over?


none really at 70...its one of those under say 50 type things...im like you I normally out it away when it gets nasty or I see the forecasts doing the 55 and LESS deal for a whole week...latest ive had mine out here has been early November.
 
I heard that mopar performance makes an intake valley gasket with the heat cross-overs blocked off. Anyone had any luck using this one?
 
You can block some of it off or just one side.

Up here in michigan I found its good to have a heated intake. Even today in 90 degree temps my water temp holds 170--175 in steady moving traffic or faster. Its not needed in 90 degree temps but 60 oh yeah, one good wot blast the intake gets cold in 60 degree temps and found it loses power.

I'm sure I'm losing some power now with a heated intake but next month at night it be 60 or colder. I do use carb spacers to help keep the carbs cool. I use intake gaskets with a steel shim inside and just drill a small 1/4 hole on each side to let the exhaust in. I heard good things about just opening one side but its too cold here in Michigan, tried it, intake gets too cold in under 40 degree temps, i drive until lots of snow comes. If its dry and 30 degrees, I'm out there, life is short. Store car just 12 weeks each winter.
 
But with the ethanol in the fuel now, the hotter the intake is, the more gas that will evaporate in the carb.
 
i think with an aluminum intake you will get enough heat transfer to do the job it will just take a little longer. on my performer i jammed a ball of aluminum foil in the crossover on each side and topped it off with some high temp epoxy. it can easily be removed. it drives fine. weve been getting temps in the upper 90s and broke 100 more than once and i think if i had the crossover i would be having issues.
 
I pulled my RPM intake off, used Edelbrock glue to seal a couple of very thin tin (eavetrough tin) pieces to block the ports off on both sides. Works great as the engine bay is much cooler, no cooked paint on the block or clearcoat on the intake. Can still smoke the tires like there's no tommorow, and with this summers temps in Alberta Canada being a crappy 15-23C (59-73F for you 'mericans) it only takes a couple extra runs around the block to get it up to give er' temp.
Seal em off. You'll be glad you did.
 
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