Does it, though? If there is no airflow then exhaust can't flow up there, so it shouldn't get any hotter than what you get from being bolted to the engine.

When I've adapted S4 N/A lowers for GSL-SE and TII engine use, I just used low-temp epoxy to cover up the exhaust port. On the TII where I used an OEM gasket, the epoxy didn't erode away, and on the GSL-SE where I made a gasket, the gasket didn't even get carbony where it covered up the hole.

 

might work ok for the intake but i have yet to find a ceramic coating that stands up to the turbo exhaust temps to date.

 

plus in the stock system air pump air is actually going thru there, so yeah i don't see how that heats anything up.

 

An exhaust port coming from the engine would certainly heat it up more than no exhaust port coming from the engine.

Robert @ Rotaryshack has been doing this mod for years and swears by it for reducing intake heat temperatures. I haven't done thermal testing before / after, but I do know that my current LIM is open to the exhaust. I'll take some thermal reading after driving a while before / after the swap, but there will be several factors at play so it will indeed bias the results

Before:
Carb
GSL-SE LIM
Block-off plate only

After:
EFI
S5 LIM
Ceramic coated exterior and gasket flange to isolate intake components
Welded exhaust port (ceramic coated barrier)

I'm also contemplating using the liquid steel stuff to seal the actual exhaust port in the engine.

So, it will be a totally different setup but we will at least be able to observe cumulative effects of these mods on intake temperatures.

 

i'd definitely be interested in the results of your testing. to be honest, i'm more of Peejay's mind on the issue because while i never went as far as welding the port closed, i did make inatke gaskets that blocked it on several engines. i never once saw evidence of hot exhaust gases making it there (i.e.: no soot, no burned gasket). i've also thought about using epoxy while i've had engines apart, but to be honest, i'm kind of a chicken-**** when it comes to epoxy use.

anyway, your manifold setup is gorgeous and at $230+ i sincerely hope it functions as you want it to. i'm inclined to think it's money well spent though. by the way, i'm really digging your build.

 

Cheers man, I sincerely appreciate that!

My S5 intake manifold was NASTY inside the ACV exhaust port, tons of carbon, black soot. Caked thick. Not saying you guys dont know what your talking about, I'm sure you know a fair deal more than myself, however I also know Robert knows his **** and I know what I see.

My last build [S4 TII block] had the ACV port welded shut on the LIM-engine side. Once I crammed a heat blanket under the turbo shield, I went from burning hot intake, to literally having frost on the manifold @ highway speeds in the summer [Washington state]. It was a totally different car before / after.

From my [limited and non-racing] experience, in a rotary, every ounce of heat reduction makes a significant and noticable difference.

The Only way I can truly do a before / after would be to drop another $70 at the fab shop and have them weld up my current exhaust port. Then $ for new gaskets that I'm just going to pull off after the test.

So, as un-scientific as it is [I work in IT - you always change one single variable at a time and test] all I will be able to show is current temps with carb / open ACV port; and temps with efi / ceramic / closed ACV port.

 

i do agree with that too.

 

While true, my point is that if the ACV is blocked off, the exhaust isn't going to go up there anyway. You will be able to save the weight of an ACV blockoff though


Ideally you'd pull the engine apart and plug the ports in the exhaust ports themselves. Then you could leave the center port open to atmosphere. I did this on one of the engines I built. And, incidentally, I used to pack the ACV area with ice. Not sure how much it helped but it was something to do.

 

Not certain I understand how that would work. Seems to me a blocked off exhaust port would still contain the gasses and temperature of the rest of the exhaust system, just not moving / flowing as the rest would be. You'd still be getting exhaust pulses and back pressure through the atmosphere in this blocked port.

I could be totally incorrect though as I have no official studies in thermodynamics.