getting ready to do my exhaust and need to know about the baffels that go in the block in the middle port. any pics of what they look like ? i need to show them to my guy thats doing my exhaust pipes . on my car the rear and middle ports share a pipe. any info on this whould be great. i already look at speedway the ones they sell 39 bucks ouch i think i can mke me own .billy
Fairly easy to duplicate-for dimensional reference, that's a 7/16" diameter head stud (and, yes, you need to use a stud-not a head bolt.) Making them is the easy part; installing is a bit more difficult. As far as how much good to they do? That's been debated for years but the general consensus seems to be unless you're running a big cam and at high R.P.M. all the time, it's a waste of effort and may even be counterproductive since it takes up space in an already too small port.
ive heard from some old local hot rod guys that they dont believe in these unless your turning high rpm's just like dale said, its taking space out of your already too small ports you have a cylinder firing between 6&7 and 2&3 15486372
I've heard the same thing, that even racers didn't use them. There has been no engineering testing that proves them to be of any advantage. And like it has been said, you are using up the already small space you have for exhaust gases to exit from. I wouldn't install them on any flathead I have.
"There has been no engineering testing that proves them to be of any advantage. " That is not correct. I did extensive dyno testing with and without baffles back in the 50's. Above 4000 rpm they definetly help. On a 315 ci engine they made 6 hp difference. I would NOT recommend them for a street engine. The ones that are available on the market are worthless junk. They are way too fat and made of cast iron...Thinning them down makes them too fragile. Home made ones need to be steel, thinner and shorter. It helps to use a "T" bar and a 1/4-20 screw down thru the heat riser hole tapped into the baffle to hold it in.
Hello! As mentioned here they might not help at low rpms, but they help some of the hot spot problems, i think. I have used a kit bought from Hot Rod and Custom supply FL, they were steel ones and easy to install, but they where abit fat. The br*** ones from Speedway are also to fat, but are easy to grind down. They come with a bad stud, stretched when torqued. I have taken the last set out of the engine, will try to run without. Br Kjell .................................. Taildragger&fenderless
You see the dimple that leads you to believe that the center stud supplied holds it in place? When I initially looked at installing these, it seemed to me that putting the fat part of the divider there effectively blocked off the center part. With just a bit of dressing (grinding) the divider fits very nicely further up the chamber just below the heat riser. To hold mine in place, I drilled a hole into the exhaust port through the water jacket hole in this area. Turned out that the previously mentioned dimple was right there under the hole I drilled. I drilled and tapped the divider and put a SS 5/16" ****on head sealed good with JB Weld. Even though the JB is holding a piece exposed to the exhaust, it will have the water running over it. (Years ago I ground inadvertently ground a hole in a SBC ram horn that I patched with JB. That thing is still holding.) The theory with the dividers is that two cylinders dumping into one area causes the inherent heat build-up in a flatmotor and that makes sense to me. With the divider in place further up, it looks like the center p***age has a nice coke bottle design that I think helps draw out the gases. I also put some of the ceramic coating on the center exhaust chamber and divider. Now, here's the big disclaimer. I have not run this engine yet. I'm still getting all my plumbing and wiring done and I hope to start it soon. I'm just shadetree and this is my common sense thinking on this, so take it for what it is worth. I do think the worth of the divider is only realized in the higher rpms for those real performance flatheads. Me, I'm just trying all these little ideas to see if I can build the coolest running flathead I can.
I made these for my next engine project. As you can see these inserts fit into the upper part of the area where the center ports merge. Essentially they block off the heat riser. The purpose of these is to form the "back" port wall and help direct the exhaust g***es down the center port. The DO NOT restrict flow but rather help it by reducing a**** other things turbulence. In addition to being held in place by the head stud I'd like to find a material that I can also "glue" these inserts in place with. This will also further improve the continuity of the port "back wall".
Wow my pics are ****py. At any rate let me say that these are hand carved/ground and in a basic form. After they are installed in the engine they will be finished to blend smoothly with the exhaust p***ages.
i ask this because jack calori said he ran them in his car the baffels and his car hauled *** he also had 3/8 x 3/8 relived eddie meyer heads, clay smith cam, potvin lincoln dizzy so it had get up and go. my car also has most of that stuff except the stroked part.so i'm still on the fence. billy
Hellmet, I would'nt use those fat cast iron ones that are commercially available and pictured above. All they are is an exhaust port plug IMO. The biggest reason given for baffles in the old days was to remove the chance of the center two cylinder cross- polluting each other when running real long duration cams as in race applications. Baffles were never intended to enhance flow I don't think.
Found a pic of the ****on head holding the dressed up cast iron speedway divider in my not run yet 8BA. Henry Floored is right, they are just obstructions unless you get them up higher in the center p***ageway located directly between the center exhaust valves. To me they make sense when they are up in this higher position. They don't when they sit down where the stud provided in the kit can hold them. I think someone screwed up when they put the studs in the kits. Guess I'll know I'm wrong when all my coolant turns to steam going out the exhaust.
Really good ideas! Good luck, trying new things on the flatheads is what its all about! Thats Hot Rodding! Br Kjell
Looks like an open exhaust chamber, correct? Can't tell 100 per cent for sure. If so have you done back to back testing with or without? It would be interesting to find out. I guess the real question is, if you could what would you change about the center exhaust p***age? and why?
That picture is about a small cast iron baffle that is turned and blocking the lelt side of the port. The motor seems to the same with it in properly or fully removed.
well that was the desesion breaker i dont want to go backwards i'm not goint to break down my motor maybe i'll try it on my spare back up motor. billy
I sledged a stuffed block center exhausts and sliced them.left and right ,have different internal shapes.tall wise .I used 3-16 s/s nickel welded to an extended and slotted stud .preheat lots then fill port and water area with sand immediatly after spot welds.Cotton Werksman did this on his 6/71 blown motor ,years ago.
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