Hi I am currently building up a french flaty for my 32. This should get a 4-71er blower and a few more performance parts. To thermally relieve the engine I wanted to install a 4th exhaust port. Unfortunately, I have not found much information and pictures about it yet. Are the channels completely separated (if so, how?) or is the additional manifold operated parallel to the middle port? Greetings from germany matthias Gesendet von iPhone mit H.A.M.B.
Lots of folks use a baffle to split the center exhaust, but it still dumps onto one exhaust pipe etc. Speedway sells the baffles....make sure you pin it in place if u use it, they have been known to get sideways and cause blockage. Be interesting to see if there really is a way to create separate ports via other feedback.
I have seen some race engines with the exhaust heat passage to the intake manifold used as an exhaust port. They had a funny little pipe coming out of the top of the engine. I don't know how effective they are.
That's exactly what I want to do - the 4th exhaust at the top next the intake. The question is just how I should share the channel. And if it really brings benefits or just looks cool. Gesendet von iPhone mit H.A.M.B.
Ok- Thanks for the answers. I read everything and look the pictures. Still unclear how the port should be shared? Weld in metal or screw in a kind of baffle?? Gesendet von iPhone mit H.A.M.B.
If you must add another exhaust port, don't worry about separating the two cylinders. The pressure will find a way out, the easiest route it can.
Have you ever noticed that a Ardun sounds more like a SBC than a flathead. That Siamese middle port has a lot to do with the unique exhaust noise a flathead makes. Taking it away is like JB Welding arms back on Venus d Milo. I run a 471 blown flatty, full exhaust and it is the nastiest sounding car I have built. I wouldn't change a thing.
This is a pic of the mod you want to do. This one was probably the most successful one ever done. It was John Bradleys engine for the 1963 Bakersfield race. The top middle pipe was a definite improvement. You can NOT use port dividers if you use this mod. The store bought dividers are useless anyway.
Rick Schnell's Slider Dragster. Unless you are doing an all out - full race build like this, there is not much reason for that 4th port. This motor develops close to 1000 hp on a high percentage of nitro, runs deep into the 7's, and sounds otherworldly.
I've seen this mod a few times and was going to look for the same picture. I'd love to know what they do about the water jacket. Does the exhaust pipe go into the valve bowl through the water jacket? It seems like this dragster motor is a dry block set up.
No, I mean the end exhaust. There are water jackets in those corners I believe. The motor I'm talking about isn't in Slider. It's in the purple FED.
That engine has the water jackets full of aluminum. So it in effect has no water jackets and they cn just bore straight through into the exhaust port
Somewhere on here is a post showing the exhaust passages very well...the guy sawed the deck off of a junk block just so. Circuitous, bu smoother than I thought it would be! At the outlets there are two basic schools of thought on how to move exhaust the last 3 inches.