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bruno

Crusty Rusty Old Rat Rodder!
Joined
Jan 27, 2010
Messages
2,213
Location
harrodsburg ky
[This may be a stupid question but here goes. Below is a picture of my intake, I want to drill two 3/4" holes into each end and run copper tubing thru it to heat my manifold with water. The copper should put out heat faster than steel tubing. My question is can I use epoxy made to use on metal to seal the two together or is there a better way. I would like to do this myself.
 

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Is the difference in heat transfer really that different to make it worth while switching to copper? Sticking with steel for the run through the log would be way easier.
 
You are probably right Sam, guess I can take it my local welder and have it tigged. I have a cheap 110 mig but I suck at welding. Any idea on the best place to put the tubing, high or low?
 
How exactly are you planning to run water through there? Just one tube through the center? A water box under the log? How fast do you need it to heat up?

If you have the room, a 1/2" deep box welded on the bottom of the log with an in on one end and an out on the other might work well?
 
Looking at the pics again, welding a box on the motor side of the log might be the cleanest and easiest. Do you get what I'm suggesting? Not sure I'm conveying my vision very well...
 
Excuse my ignorance... but why heat an intake manifold when heat is the enemy?

.

same question. I thought cooler intake equalled denser intake charge eqalling more air and fuel mixture. At any rate you could possibly thread a male npt to compression fitting in the end plates of the intake and run copper tubing through them
 
Lots of talk when changing exhaust manifolds to headers and losing the warming effect of the manifold. Tom Langdon sells water provided heat plates that just attach to the bottom of the intake manifold to supply some heat back. Might be more of a problem on the inline motors than V8s.
 
[S[S I dont even know what y'all are even trying to do .. Ive herd of a bucket of ice with copper tubing gas line run threw it .. [S[S
 
From what I understand The fuel has a cooling effect on the manifold and will keep it from staying atomized. When it turns back to liquid it will flood the cylinders with raw fuel, not good. On V8s the engine heat keeps the manifold warm, on I6s & I8s they are generally heated by way of a butterfly valve between the intake and exhaust manifolds. Intake manifolds, especially steel ones can actually frost up, even in warm weather. Most aftermarket inline manifolds have some sort of hot water system to heat them. Tom Langdon explains it the best.

Sam I think I will take your suggestion and have a rectangular tube tigged to the engine side of the manifold and have heater hose nipples in the ends. My Buick straight 8 water pump has 3 nipples in it so I would only have to put a tee in the return heater hose. There isn't enough room on the bottom of the manifold to do anything.

Thanks, Randy
 
Oh ok I dont know much but I do remember of seeing a butter fly thinggy on my 240 I had in my 65 truck I had no idea of what it was though .
 
First off - KOOL ENGINE !! I get the idea of heating the manifold, you will get some icing on it in cool weather... Running a copper tube through the manifold would be cleaner looking (I would just braze the ends) but probably wouldn't heat the manifold as well as a pipe welded to the outside of the body as other have suggested. I'd think that in warm weather you wouldn't really want to heat it up though - some kind of flow control valve like used in heater hoses might be a good idea.
 
On my Chevy online 6 I had a water heated manifold. The heat helps volitalize the gas into vapor better in the manifold. V8s have the entire engine under the manifold to heat it.
 
Here's a couple pics of vintage Edmunds straight 8 manifolds for Packard engines I think... you can see they incorporate a water passage into the plenum. What did Buick use on their dual carb intakes?
 

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Buicks ran manifold heat, they had 2 exhaust manifolds and each one bolted to the intake right below the carbs. They were only available in 41 and 42, very expensive when you find them and the exhausts are prone to cracks.
 
Like sneakysnake said above, copper and steel can be silver soldered. Both surfaces need to be sanded thoroughly clean and "Stay-Silv" white paste flux needs to be applied. The joint can then be made with 45% silver solder found at local HVAC supplier or WWGraingers....maybe even McMasters Carr. Typically it is sold in 1 or 3 troy oz. plastic containers.

I would make a number of trial joints before attacking your project and would suggest a oxy/acetylene torch and not a handheld propane. If the torch set is a normal size, use the smallest tip at your disposal to minimize warpage or distortion.

Correct heat is the trick on ANYTHING that has to look nice. Good luck sir.
 
what if you just built a tin shroud like a heat stove to allow the heat from the pipes to radiate upwards to the intake? would warm up faster than water cooled and you could install a flapper valve and run it off vaccum and a temp controlled vac switch

You could also mount your intake closer to the exhaust

or you could weld a length of channel to the outside of the intake through which to plumb coolant
 
OK i'm late to the game here, sorry if this is stale, redundant, annoying, etc....

i can verify that your seat-of-the-pants instinct is correct -- evaporating fuel in the carb/intake is isothermic, eg. takes a lot of heat to evaporate the gasoline. i actually *measured* it --

http://worldpowersystems.com/AMC/195.6OHV/Intake/

scroll down to "fuel charge temperature".

the catch is -- the fue::air mixture doesn't hang around very long at all in the intake system between carb and intake valve, and i am personally not convinced that any system will add heat to the mixture, assuming that your goal is to reduce droplet size on it's way to combustion.

Smokey Yunick was concerned with this, in his later adiabatic engine experiments. but the motor industry has gone another way from that, and achieved great results. which doesn't necesarily mean Smoley was wrong; "industry" cares most about cheap and repeatable.

i think overall it's *velocity* that does the most good; the carb (or FI/EFI) system makes smallish droplets, the intake delivers them to the cylinder, they swirl and burn. the tiny burning planets of fuel, if given enough time (THAT'S THE BIGGEST CATCH!) release all their energy.

the fact of "open throttle == cool fuel" to me tells the whole story. the velocity (feet/second) would be easy to calculate, and that time, in milliseconds, is how long you have to impart heat energy to the gasoline droplets.
 

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