I was wondering if it's an intentional temperature buffer for the gasket sealing edges ...

 

That actually makes a lot of sense, to get the gasket edges away from the very hot gases. I'm not sure what it does to flow tho, but I imagine its not so great.

 

The gaskets are always larger to keep them away from the direct heat. what's strange about this engine is that the hole to the manifold is larger bya substantial amount over the exhaust ports in the engine and the gasked is much larger than that. It's realy odd and doesn't make much sense. If you could see the shape of the manifold and of the ports in the engine all put together, you'd wonder how it flows anything at all.

 

if anyone has the actual dimensions of housing exhaust ports that would help me out a lot, I don't have direct access to measure them myself at the moment, the end housing ports are wider than the center one

 

 

I could give you a tracing of the actual port runner outlets on the housings but it wouldn't tell you much. The ports themselves have much less area and the transition to the runners is terrible. I have no doubt it would be possible to use a smaller exhaust runner machinged into a new sleeve and still pick up flow. The center runner is the opposite. While the transition is terrible, the area of the ports is far greater than the area of the runner. It's all a big mess.

 

I'm only looking for the actual height and width dimensions on the exhaust port outlets if you can be so kind please

 

The outer runners coming out of the side housings are 1 7/8" tall X 1 1/16" wide. The center runner out of the intermediate housing is 1 7/8" tall X 7/8" wide.

The size of the holes in the exhaust manifold are much larger than this and the gasket is far larger still but these are the relevant ones.

 

Thanks, RG, I owe you one.

I'm just trying to finalize the flanges for the custom manifold so I can get them waterjetted. I'm not allowed to touch the ports so there's nothing I can do about the rest of the situation. I've pretty much finalized the design, wwon't be much more than lightweight knockoff of the OE manifold with some performance improvements, but still emissions compliant.

 

You do know that I have the flanges drawn up in CAD with the proper sized exhaust ports don't you?

 

no


AutoCAD? TeamMazdaRX8@aol.com

I did an eMachineShop print just to see what they'd charge, glad it won't cost me that

 

I have it drawn up as a 3 piece flange much like you do. The outer flanges are the same just reversed and obviously there is a center one. It's less metal this way which is cheaper and it is less likely to warp over the length of the flange when you weld it.

 

Don't be coy, what's it going to cost me?

 

Sorry I got offline and then I came 50 miles across town to my girlfriend's house. I'll be home tomorrow.

 

Change your mind? I figured you might like some free flanges or something. I work for a stainless fabrication manufacturer, we have a waterjet ...

 

so basically, there are no marginal gains by developing a header for the renesis? So what's the weight differences between the stock one and the one being developed here?

I take it this is just a weight savings mod more then a power adder. Why don't you just yank out the a/c if that's the main objective?

 

that's on the list too, just got the SpeedSource pulley kit which has no AC drive pulley

 

^^^^Like that way of thinking.

 

I need to resize the images that I have in picture form so everyone can see them here. As far as the format they are in on CAD, they are a .prt file. See if you can open that. If so, I'll send them to you. If not there isn't much I can do other than going back and doing it all over again.

 

I'm pretty sure I can convert that into an appropriate format

 

What is your e-mail address?

 

TeamMazdaRX8@aol.com

 

e-mail sent.

 

got it, thanks

 

anyone ever think of a 3-2-1 header design?