Interesting. 400 horse is disappointing but nick mentioned only 165# cyl. pressure.
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Nicks Garage tests a 440 with manifolds, Maxie manifolds, and headers
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Stock 440 manifolds are 35 horse loss over the Maxie manifolds. (and 50 lb/ft of torque!)
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418/463 with headers and no timing or carb tuning.
I thought so too. Looking for the specs, but a buddy put together a mild hydraulic cam/ported heads 440 and got close to 500 horse and darned near as much torque.
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Be kind of interesting how the numbers change if ran through a full exhaust.
Mark
Mark
Interesting test.
H.P. Exhaust Manifolds: 380 HP and 398 TQ
Max Wedge Exhaust Manifolds: 414 HP and 449 TQ
Headers: 418 HP and 465 TQ
What surprised me is how good the Max Wedge exhaust manifolds were - almost equal to headers!
H.P. Exhaust Manifolds: 380 HP and 398 TQ
Max Wedge Exhaust Manifolds: 414 HP and 449 TQ
Headers: 418 HP and 465 TQ
What surprised me is how good the Max Wedge exhaust manifolds were - almost equal to headers!
Exactly! Chrysler engineers had it going back then. And the Max Wedge exhaust system was cool as well.
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But......headers don't make power...the engineers designed the engines and manifolds to work to make the best power....
Fixed it for you.
Headers still make more power even on a stock engine, although the differences aren't as large.
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I cant say that i am surprised how well the maxies worked. In the early sixties, several manufacturers made cast iron virtual headers for their maximum performance engines, that worked even better than the maxwedges did, notably ford, for the 427, and pontiac for the sd 421.(pontiac even cast some out of aluminum for their drag cars, the swiss cheese cars). I think, but dont know for sure, because nascar didnt allow headers. Also, why mopar devised a true cast iron tri-y header for maxwedges, just before the hemi came out.
I have only seen pictures, never in real life, and they are incredibly rare. I dont believe five grand would buy a pair.
Edit : Just checked, Ten grand wont buy a pair!
I have only seen pictures, never in real life, and they are incredibly rare. I dont believe five grand would buy a pair.
Edit : Just checked, Ten grand wont buy a pair!
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Over the years I have wondered why no one fabricated a set of Max Wedge exhaust manifolds
out of tubing because they are superior. One pipe coming down from the manifold is alot nicer
than a set of twisty headers. Also, the upsweep of the exhaust out of the combustion chamber
makes more H.P. and Torque because of the straight shot. The exhaust ports on 906 heads are
really handicapped as you can see in the video when changing the manifolds. When I ported
mine, I took them out to gasket size and they look Humungous now! They have alot of meat
on them.
out of tubing because they are superior. One pipe coming down from the manifold is alot nicer
than a set of twisty headers. Also, the upsweep of the exhaust out of the combustion chamber
makes more H.P. and Torque because of the straight shot. The exhaust ports on 906 heads are
really handicapped as you can see in the video when changing the manifolds. When I ported
mine, I took them out to gasket size and they look Humungous now! They have alot of meat
on them.
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I was in Sparks Nevada last year at the Summit racing store. In the lobby area, they had some display parts on the shelves. I looked at a set of the Trick Flow 240 heads. The exhaust ports of those were not that much bigger than the gaskets that come in a Fel Pro gasket set. I was surprised because the TTI gaskets that come with the 2" headers match the header ports.
If the TF 240 heads make power with exhaust ports barely bigger than stock, there must be some reason for why they did not machine them any larger than they did.
My own bonehead logic tells me that the port on the right above would flow better but it is in conflict with the TF 240 ports. I am not experienced enough to understand or explain why.
If the TF 240 heads make power with exhaust ports barely bigger than stock, there must be some reason for why they did not machine them any larger than they did.
My own bonehead logic tells me that the port on the right above would flow better but it is in conflict with the TF 240 ports. I am not experienced enough to understand or explain why.
PRHeads
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I bet you’d see a bigger spread in the power differences if you did that test on something that made about 200hp more.
At less than 1hp/ci, that’s a pretty mild build.
To put the size of the 906 ex port into perspective......as to how big is big enough?
For the FAST heads I’ve done, that have been dyno tested at over 600hp with ex manifolds in place and using 2.5” pipe, and have gone 133mph in a 3900lb A12 car in legal FAST trim....... the openings were only as big as the stock style exhaust gasket(which is barely bigger than the stock opening).
As has been mentioned, the TF head ex ports are quite small...... and numerous people have made 700+hp with those heads ootb..... with their small ex port openings.
At less than 1hp/ci, that’s a pretty mild build.
To put the size of the 906 ex port into perspective......as to how big is big enough?
For the FAST heads I’ve done, that have been dyno tested at over 600hp with ex manifolds in place and using 2.5” pipe, and have gone 133mph in a 3900lb A12 car in legal FAST trim....... the openings were only as big as the stock style exhaust gasket(which is barely bigger than the stock opening).
As has been mentioned, the TF head ex ports are quite small...... and numerous people have made 700+hp with those heads ootb..... with their small ex port openings.
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Gus chiggins
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Really like the max wedge manifolds. Like somebody said here too bad nobody makes a tube version, even a set for a 383 would look pretty cool. Of course the 383 is a different animal.
I wanted a set of Max Wedge manifolds for a long time now. I actually could have bought a set for around $500. about 7 years ago. I wish I had the money then and bought them. There are several reasons why I wanted them but hesitated too long and lost out. First, I love the way they look. Second, and most importantly, they open up a lot of space down the sides of the engine so it appeared that access to the starter and steering box and such was improved. Third, the plug wires run below them avoiding some of the rising heat. Forth, they were cast iron and most likely last a lot longer than steel headers. On the down side, I thought the collector flange had two openings, not one and obviously I was wrong. The big reason I hesitated, was I read somewhere that you couldn't use them on a street car with a dual master cylinder due to the closeness of the manifold to it. Whether it would hit it,(depending on body) was one thing, but the heat was supposed to boil your brake fluid. I recall asking if you could make a shield between the the manifold and the master cylinder and was told there generally wasn't room unless you use a single master cylinder. Can anyone confirm the boiling brake fluid ??
Well I simply typed "Max Wedge" into google and looked at the photos. I haven't seen any dual reservoirs yet. All of them look like this:
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The ones i was referring to were the tri-ys, which did have a double exhaust exit, unlike the normal maxwedge exhausts.
As for the normal maxwedge exhausts, i honstly dont know if the will fit in a post 65 car. The engine is moved back a couple inches on the k-member in 66, and i dont know if there is clearance to a double master. There may be, but it will be closer than in a 62-65, and that may be the source of the boiling fluid rumor.
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