The Stovebolt Site Forums The Shop Area The HiPo Shop Intake manifold heat..

Hi all,

I am considering removing the dual Carter/Weber carb setup & Fenton intake from my 261, and putting the single Rochester setup back on it. This would leave me with the stock 261 intake manifold and the Fenton exhaust manifold (I would like to keep the Fenton exhaust on there).

At the moment, the Fenton intake is heated via Langdon’s water adapter plate. I really would like to remove the water-heated setup, as it is just another potential point of failure (too much complexity). I’m trying to make things simpler under the hood.

If I decide to run my factory intake with no provision for heating it, what do you think I can expect as far as drive-ability?

If running without a heated intake will be an irritating problem, Is there a method to extract exhaust heat from a Fenton ex manifold to warm a stock intake? I drive this truck a lot- freeway, traffic, city, canyon roads᠁you name it.

There are two ports in the Fenton exhaust, but I don’t remember how these get plumbed for induction heating

Thanks for any advice,

Dave

I can't answer your primary question but if you do go back to the the original manifold and single carburetor, use a Carter YF instead of the Rochester.

Thanks Otto.

This will be a summer project, when I get a short break from work. I know that long ago the Fenton exhaust were sold as a kit with a steel plate for exhaust to be plumbed to the intake, but it is not sold anymore. I will probably have to fabricate a steel plate and run some steel or copper pipes to the factory intake.

Use a piece of aluminum plate about an inch thick, sized to bolt to the bottom of the intake, and drill it for a couple of pieces of 1/2 inch stainless steel tubing. Plumb the tubing to the ports in the Fenton headers so exhaust gas can circulate back and forth through the plate. You can't plumb the exhaust gas directly to the aluminum- - - -it will erode very quickly. Drop me a pm with your email address and I can provide a sketch with the basic layout of the heat plate. Water heat is a waste of time- - - -when you need manifold heat the most is right after startup- - - -when the coolant isn't up to operating temperature.
Jerry

Heat plate will help.
My 2 cents: I was running Fenton cast headers with pipes and plate on stock intake. Back to stock exhaust manifold, can't tell any difference in power but has better cold drivability.

I'll send you a PM Jerry- thanks. Cutting and flaring stainless is something I have yet to tackle- and it doesn't sound fun. I'm guess that the flaring/cutting tools that I have will not handle stainless?


This might be the easiest roue, if that thin plate in the pic is steel.


I'm sure that the stock setup provides WAY more heat to the intake...I'm not surprised that it drives better in the cold. I don't want to re-do my exhaust (I love the way it sounds right now), so the Fenton split exhaust must stay!

I kept the fenton on way too long, switched back to stock exhaust manifold and haven't looked back.

You don't have to flare- - - -use compression fittings.
Jerry

You need some heat. Measure the outside dimensions of the intake/exhaust sandwich gasket. I forget now what it is, but say its 3X3. You can order a precut piece of 3x3 steel plate, 3/8 or so, maybe 1/2, on ebay. Using the gasket, mark the four holes for drilling, drill the attachment holes.

Use dykum or a sharpie and color up the top of the plate, lay the gasket on, put some bolts to hold the gasket in place and scribe the outside of the gasket and the inside of the gasket. Drill two holes for brass fittings within the inside scribed lines. You will be tapping tap holes for NPT threads. Sort out what size lines to use before you drill these two holes. Fenton use to specify copper lines, so my guess is that ni-copp, which is stronger then regular soft copper tubing, would be ok to use. Compression fittings are fine. Whatever fits the Fentons.


Then cut away the excess on the outside scribe lines. Dress the outside down so it looks pretty. Little paint to match the intake.

Jerry's method is more professional. Mine is completely backyard hacker work, lol.

Thanks guys- this is going to be the first project I tackle his summer- no more water lines.

A stock intake manifold needs some heat all of the time. It benefits from more heat during startup and until the engine reaches operating temperature. That transition is the job of the original flapper inside of the box.
Heating the intake with water is only good for providing the correct amount of heat to the intake manifold once the engine has reached operating temperature, which means that it isn't exactly useless, just not practical in you want to hop in the truck and go with a cold engine.

52 Carl- yep, that has been my experience this winter. Summer months, all is fine where I live, but the truck doesn’t run so great around town after a start in the winter.

There is a better way...

That is one of the nicest looking split manifolds I have seen. Here is a pic of one that I picked up, but did not end up using. Yours has a much larger ID for the extra pipe