conical manifolds

[jeff walker]

Has anyone experimented with these and what is your opinion?.....................

 

[Glenn Gates]

Please clarify.

 

[eekern]

Haven't tried one but apparently nova believes in them as they offer them for most apps

 

[jeff walker]

Conical manifolds taper from the pipe end to the ex port, it works like an extension of the pipe.

 

[shoboat]

Jeff,

Where do you get yours from?

I have been wanting to try them.

Free horsepower !

Thanks,

Mark Sholund

 

[Dasboatman]

OK, I'll bite. What the Sam Hill is a "conical manifold" - I have never heard the term. A pic would be nice for anyone's application. CHEERS !!! Bob

 

[Brian Sorgente]

See post #4.

Basically a cone shaped header that follows the taper of the pipe.

 

[bermudadude]

its the PROPER way to make a header.everybody is doing it the easy way. cant blame em,if u study it its hard to make right and have a versatile header thats good for multiple applications.

Andy Brown was getting them made for the mac.21 and .45. then they where cnc'ing them but then that all stopped.

the quickdraw hot pipe uses 1 (not a large taper but better than nothing)

a couple of the expensive gas engines use em

 

[jeff walker]

I have made my own take a 1/2 inch or 7/16 rod put it in the manifold and kinda stur it, it takes some force but get the id the same as the end of your pipe around 5/8 it works, make sure that your coupler does not neck down between, this will cancel the effect. I am working on a flaring tool like a muffler shop to do a better job . I will show when done. To all the folks that don't believe this works the world car guys banned it as an unnecessary to completion, it does work but it does use more fuel. Look for conical manifolds on ebay to see a car example.

 

[tnrcboatracer]

One thing to note, the expansion of the flow should start slowly, and then accelerate. I.E. use a smaller angle at first, and then, once the flow starts expanding, you can increase the angle. Otherwise there is a risk of flow separation and the pipe actually becomes a cylinder instead of a cone (as far as the gas flow is concerned).

 

[dwilfong]

I use a boring bar to put a 1 1/2 deg tapper in my CMB 1.01 header.

I use a stock thick wall header to do this.

The CMDI header has this done from the get go.

 

[Tim_Duggan]

I use a boring bar to put a 1 1/2 deg tapper in my CMB 1.01 header.

I use a stock thick wall header to do this.

The CMDI header has this done from the get go.

I too did this about a month ago. It really shows up that they aren't dead straight! I guess thats to be expected though.

 

[Lennard Cuenco]

sounds good

has someone made a video showing before and after using their conical manifold? involving a radar gun would be cool

 

[Andy Brown]

sounds good

has someone made a video showing before and after using their conical manifold? involving a radar gun would be cool

Straight makes more low end torque. Taper and increased taper make more top end rpm at the cost of low end torque.

Straight thick headers that create a big step at the transition to the pipe are bad news.

They don't do anything good. Making any kind of taper on them will show an overall improvement.

 

[lohring]

Quickdraw's headers have been made this way for a long time. Gasoline two strokes with triple exhaust ports find that there is a lot to be gained with the correct exhaust manifold shape. See the picture below for a summary of what some kart and motorcycle racers have found to be optimum.

Lohring Miller

 

[lohring]

I should add: "[SIZE=11pt]The nozzle idea hasn't been a success in reality for anyone I know of when added to a single Ex port.
No matter how high or wide you make one of these it seems you cant make the area"too big" to loose the exit velocity as happens with
big T ports or triple ports.[/SIZE]"

Lohring Miller

 

[jeff walker]

Check Novarossi Americas site they are selling them for .21 and.45 sizes, I don't believe they would sell if worthless!!!!!!!!!!!!!!

 

[Andy Brown]

Check Novarossi Americas site they are selling them for .21 and.45 sizes, I don't believe they would sell if worthless!!!!!!!!!!!!!!

And we at CMDi would not have made them since 2001 if they were worthless.

 

[jeff walker]

Andy: I have been to your site countless times I never saw them, but if they weren't worth something they would not make them!.............jw

 

[Andy Brown]

Andy: I have been to your site countless times I never saw them, but if they weren't worth something they would not make them!.............jw

All of our headers at CMDi have always been tapered. We just never advertised the fact.

Kinda like Chevrolet does not advertise the exhaust manifold I.D. on a 2014 Silverado truck, but they do what works best!