The Stovebolt Site Forums The Shop Area The HiPo Shop GMC 228 Fenton Headers and Manifold Heat

Hi guys,
I have a 1949 GMC FC102 and a 228 installed. It came with Fenton headers and a Howards (copy) aluminum intake manifold. It has no intake manifold heat at present. Been researching pros and cons of the exhaust heat for the intake by tapping into the Fenton bosses vs. plumbing water heat into a plate mounted onto the base of the intake manifold pocket area. I prefer the exhaust heat for a broader application from engine start to warm up. I understand how the water heat is plumbed to “flow” into the intake base pocket area designed for heat. But, I don’t understand how the exhaust heat plumbed from the fenton headers into the intake base “flows” using a kit similar to the attached photo.

How is the hot air moving and “flowing” through the base plate if it’s connected to two opposing supply (pressure) sources from the Fenton headers?

Your help is always appreciated. Thank you.

Since all cylinders do not fire at once, there is staggered pulsing going on which should allow movement of hot air flow into the cavity in the bottom of the intake.
My concern with this setup compared to the original design is that I wonder if it provides rapid enough heat at startup on a cold engine, especially on a very cold day, or just as important, does it provide too much heat once the engine warms up, particularly on a very hot day.
My guess is that the design is merely a compromise between those two factors. That, or they figured everything out and it works flawlessly.

Exposing that aluminum intake manifold to direct contact with exhaust gas is a really bad idea. Ther's an alternative method to get exhaust heat into that area, but that kit would be the absolute last option I would consider. Send me a private message for a phone number, and I'll describe a much more effective and safer method. It's a bit too involved to discuss with a series of forum entries.
Jerry

Thank you 52Carl! I would have never thought that of the staggered pulsing. I would prefer to go back to stock, but there was so much done and invested in this aluminum intake and Fenton headers before I got it that I just want to see how it will run. I have the original carb, intake and exhaust manifolds if I decide to go back.

Jerry, I did PM you. Thank you.

My offy/Fenton setup has been plumbed this way for at least 20 years and 200K miles. Is it perfect? Dunno, I still have to use the choke to get started and a bit of throttle to keep er idling till warm. Is the bottom of the manifold corroded with exhaust gasses? Dunno that either and I'm not about to take is apart to look. The carbs ice up in cold damp weather. They do not vapor loc in hot weather. They have thick heat insulators from some GMC truck or other. All in all seems to work pretty well.

I have always wondered about the coolant heat supplied set up.
If the engine is warm enough to be circulating warm water, does it need the heating at that point?

A rough sketch of the exhaust heat method I use is on the way to you. Maybe the USPS system will get on the ball a little better after the holiday rush!
Jerry