tons of threads out there for the chevys sixes. less for the fords and even less about the flatheads. by splitting the stock manifold i will loose the flapper valve used to direct heat back to the intake. it seems to me they only serve their purpose while the engine is warming? i will still be using the stock intake (for now). if anyone else out there is running this setup, i'd like to hear about it.
I have a good friend of mine that is running a split manifold on his flathead in his '50 panel. He had a set of HEAVY flanges cut, and then made a set of headers to fit using one of the speedway kits. He has been happy with it ever since, and did not have any noticeable problem with warming it up. Granted it doesn't start up and take off driving like a new honda. But its a flat head. It never did.
Cars have a back half outlet and trucks have a front half outlet. Use the car manifold as a base and saw the outlet off of the truck manifold, use a holesaw and cut a hole in the car manifold in the front half outlet position and weld the second outlet in place. I took the heat riser flap out and welded a 3/16" plate in its place. Old timers say it sounds better if you only block about 75% between the front and back halves. I don't have any warm up problems and it sounds great. I have had it in my '51 car for over 10 years now without a problem.
thanks for the replies. i know it's not the most common setup but, do you know of any sound or video clips? i'd love to hear and see one before i do it even though i'm going to split them anyway.
Sorry, no videos. I don't even have a decent picture of the setup and if I did, I probably couldn't figure out how to post it. I'll try to get some help this weekend.
Hi I recently had a manifold split, where they welded on a new additional front exit. It wont fit my car, because the exit is too near my crossmember. I am willing to sell it for a hundred bucks- it cost me more, but i dont need it now...
The Jalopy Journal
