Do your Coolant temps and AIT's a favor

[N.RotaryTech]

Horsepower, ted is the only one that mentioned this.
We dont care if there is more or less horsepower.
This is a reliability mod, And for the ppl that remove the emissions system, an don't care about egr.
Yeah this might be something significant, possibly new, an I thank Titanium for posting it up.
He is contributing to the community a little helpful piece of info here.
Lets give it a try here an there and post up results, before bashing it and claiming that this wont make a significant difference.

About significant difference.
Some of the things we do with our rotaries probably don't make a significant difference. Ive heard of lots of little things to do, weather it comes with rebuilding an engine, removing stuff from the engine(emissions removal), turbocharging, tuning, etc, That help in a little way with performance, reliability, etc.
Its not all about a significant difference.

[RETed]

Hmmmm, I didn't realize critical thinking got thrown out the door just because you think someone is an authority (mind you, I'm using this pretty loosely)...
I didn't realize that just because I'm the only one objecting to these conclusions, it's called "bashing" now...
Apologies if I tend to be suspicious of claims from any tom, dick, or harry...

Nor I guess you think it's rather normal for someone to call me "teddy"...
Funny, cause no one else calls me that.
Just for the record, my legal name is "Ted", not "teddy", nor does anyone else call me "teddy".
I guess you find it appropriate that someone that I don't care for is allowed to call me that?

Oh, if you want to drop your temps and increase spool up on your turbo, might I suggest a turbo (turbine) blanket?
These have been used for years and have been proven (and produce more significant results over these posted in this thread).
Oh, wait, but you already knew about that, right...?

Hey, sorry for raining on your parade.
I'll let you get back to your normal scheduled programming, and excuse the blip on your TV screen.


-Ted

[kuromi7]

Ted's softening up, he went easy on you guys...he must like you. This, plus teh other mods to drop intake temps eventually add up.
- Phoenix7 (logged in as Brooke apparently.)

[classicauto]

One thing I also did to reduce turbulence was to weld/smooth the two little EGR ports in the exhaust sleeve itself.

Obviously, its doing dick all by itself, but its another item that may just help keep that side of the engine cooler, and thus, take some load off the radiator.

But yes gas will still go around the sleeve, but there's yet to be a real solution to that problem being that the housing is AL and the sleeve is ferrous.

[N.RotaryTech]

Ok, "bashing" probably wasn't the word to use.

Critical thinking? Sure.

I tend to reply to "critical thinking."

[vex]

Originally Posted by RETed

...
Oh, if you want to drop your temps and increase spool up on your turbo, might I suggest a turbo (turbine) blanket?
These have been used for years and have been proven (and produce more significant results over these posted in this thread).
Oh, wait, but you already knew about that, right...?

Hey, sorry for raining on your parade.
I'll let you get back to your normal scheduled programming, and excuse the blip on your TV screen.


-Ted

Can I imagine you laughing while typing that?

The same principle still applies with the turbo blanket. The turbo will only spool as fast as the temp/pressure differential is available (Which I know you know but for everyone elses benefit), so the more heat you keep within the turbine the faster it will spool. Of consequence plugging the hole will give more exhaust gas temperature to the turbine than a blanket alone. This modification would be to isolate the exhaust gases from exchanging heat through contact and heat soak directly to the coolant passages. I imagine one could theoretically further increase the heat rejection benefit of the coolant passages by filling the egr void and plug area with an insulator material (silca comes to mind as an example) and then blocking off the locations themselves. Though I'm personally not familiar with the passages and so can not say it would be a good thing or not and may be more of a hassle than is really worth.

More to the point blocking off these passages may at the most provide a good 50-100F (I pulled these numbers out my ass though) temperature difference which to a turbo isn't a whole lot and wouldn't really be noticable when the EGT's reached normal operating temperature. Basically it's something that, by itself, is not worth it to pull your engine and take apart to do.

You could however decrease spool time by increasing the temp/pressure differential. There's (more than) two ways to do this. One is to allow a majority of the exhaust gas to go directly to the turbine, or cool down the exhaust gases as quickly as possible after the turbo. One can let their imagination run from there I figure.

[classicauto]

FWIW, I noticed zero actual increase or decrease in preturbo EGT's before and after this.

Coolant temps - mine vary because of the way my fan is setup (meaning hits traget temp, fan comes on, temp goes down, fan goes of...) but there was no appreciable difference in my setup regarding water temps before or after.

As for my AIT - I'd have to have had a sensor right in the LIM to quantifiably say one way or the other - but I do not.

One thing I can tell you with 100% certainty - it was fun to do and made me feel better

[vex]

Originally Posted by classicauto

FWIW, I noticed zero actual increase or decrease in preturbo EGT's before and after this.

My thought is that the increase in temperature would actually be registered as a dT/dt (change in temperature with respect to time). Meaning you'd come up to temp quicker, but that probably comes out in the wash with the thermocouples. Dunno though.

I know i've been trying to explain what I mean for a few posts now but it's hard to make sense and keep it simple without writing a huge article on it.

[TitaniumTT]

Originally Posted by kuromi7

Ted's softening up, he went easy on you guys...he must like you. This, plus teh other mods to drop intake temps eventually add up.
- Phoenix7 (logged in as Brooke apparently.)

I was crowned the evil forums Epic N00b Powerhouser so I wouldn't consider that the slightest bit insulting or demeaning in comparision to some of the things that I've said to people soooooooooo, whatever.

On to more important things. I never once claimed anything about horsepower becuase I never had a chance to dyno anything nor would it make a shit of difference because the engine was rebuilt with better housings and different seals so any claim would be completely bullshit.

I didn't mention any numbers about the AIT's because the proper place to measure those to make the comparision would be in the LIM which I'm not.

I mentioned the coolant temps that saw a difference that were logged.

And someone explain to me how exhaust gases can get past the PLUG IN THE PORT that I built?

[RETed]

Originally Posted by vex

I imagine one could theoretically further increase the heat rejection benefit of the coolant passages by filling the egr void and plug area with an insulator material (silca comes to mind as an example) and then blocking off the locations themselves.

You're right, but here's the problem...

How do you get (the silica - "silca"[sic?]) to stick to the metal housings?
RTV'ing the passages (on rotor housing, side irons, and intake manifolds) has been done before, but RTV only has a claimed 700F intermittent temperature resistance.
Almost anything else will either:
1) burn due to temps?
or, 2) come loose due to heat expansion / contraction from the engine.

The good thing is that once everything is plugged up, it's a dead end.
So, the plugs that are closest to the engine (i.e. rotor housings and side irons) are getting the hottest.
The plugs at the intake manifold should hold up fine?


-Ted

[vex]

Originally Posted by RETed

You're right, but here's the problem...

How do you get (the silica - "silca"[sic?]) to stick to the metal housings?
RTV'ing the passages (on rotor housing, side irons, and intake manifolds) has been done before, but RTV only has a claimed 700F intermittent temperature resistance.
Almost anything else will either:
1) burn due to temps?
or, 2) come loose due to heat expansion / contraction from the engine.

The good thing is that once everything is plugged up, it's a dead end.
So, the plugs that are closest to the engine (i.e. rotor housings and side irons) are getting the hottest.
The plugs at the intake manifold should hold up fine?



-Ted

Edit: Sorry didn't realize I had missed an 'i'
Silica is glass (or more commonly known as: sand or silicon dioxide). I chose that media as the insulation because it can be small and remove about 99% of the air that would be in the chamber (since the silica particulate is so small). Thermal expansion shouldn't matter much if at all because the particulate itself is so small. When the chamber volume expands the silica will move to compensate, when the chamber volume decreases the silica *should* be able to move to compensate.

http://en.wikipedia.org/wiki/Silica

Another alternative would be Aerogel. It is mostly composed of air which makes it tremendously light. It also has an increased strength compared to other similar materials of equal dimensions. The real benefit is that they are wonderful insulators. This is the stuff that astronauts have in their suits to protect them from solar radiation (the heat, not the gamma). The trouble is I do not know the thermal expansion rate nor any of it's physical properties.

http://en.wikipedia.org/wiki/Aerogel

What I would find interesting and I think a little beyond anyone's skill on this forum would be to use thermoelectric coolers to cool the chamber wall and dissipate the heat directly into the insulation that holds them there. Granted you'd need to run wires and find a way to protect them from being melted/fried (probably have to encase them in the insulating material itself). Beyond that you should see a decrease in temperatures without increase in coolant temps (though this is not something for nothing). The trouble is as the heat increases and the thermoelectric device attempts to cool it, the more current will be drawn until either the wires burn up or the ceramic breaks apart. But it's interesting to consider.

http://en.wikipedia.org/wiki/Thermoelectric_cooling
http://www.fujitaka.com/pub/peltier/...FRJM5Qodnjbf9A

[RETed]

I am not going to mess with stuff that is basically very small tiny bits of glass.

I've messed with aerogel, but only with speakers...I'll leave that stuff with transducers.

Peltier devices are notoriously inefficient devices.
By the time you create enough cold to counteract the heat, you've produced enough (or not enough?) current on the order of significant horsepower.
So all that did was load the engine down or blow your alternator?


-Ted

[vex]

Originally Posted by RETed

I am not going to mess with stuff that is basically very small tiny bits of glass.

I've messed with aerogel, but only with speakers...I'll leave that stuff with transducers.

Peltier devices are notoriously inefficient devices.
By the time you create enough cold to counteract the heat, you've produced enough (or not enough?) current on the order of significant horsepower.
So all that did was load the engine down or blow your alternator?


-Ted

Hence why I didn't think it efficient at all but a nifty science experiment (thermoelectric). How's the Aerogel? I've never had a chance to work with it, does it compress and expand agreeably with metals?

As for the silica, I don't think it would cause any problems unless the metal deteriorated enough to cause them direct access to the combustion chamber or leak into the oil reserves (which I don't think they would at all unless there was a catastrophic failure). Combining the silica with a metal based epoxy or resin would eliminate any fear that a rouge silica particulate would find its way into a place it shouldn't be.

The only other option would be to fill the chamber with insulation material (fiber glass) and some aluminum.

[classicauto]

Originally Posted by TitaniumTT

And someone explain to me how exhaust gases can get past the PLUG IN THE PORT that I built?

I don't think it can.

Rather, that exhaust is still getting around the sleeve itself and thereby heating that entire aluminum portion surrounding it (which is cooled by the jackets). Despite the fact that it can't get out of that chamber now since you plugged it - that portion of the AL on the housing is being blasted with exhaust.



I tried to minimize it by welding shut those holes in the sleeve, but the leading edge of the sleeve still doesn't seal against the housing and until it can, gas will still go around (a bit...)

[RETed]

Originally Posted by classicauto

Rather, that exhaust is still getting around the sleeve itself and thereby heating that entire aluminum portion surrounding it (which is cooled by the jackets). Despite the fact that it can't get out of that chamber now since you plugged it - that portion of the AL on the housing is being blasted with exhaust.



I tried to minimize it by welding shut those holes in the sleeve, but the leading edge of the sleeve still doesn't seal against the housing and until it can, gas will still go around (a bit...)

Yep, despite his limited intelligence, he still can't quite grasp the idea of exhaust gases getting around the exhaust sleeve...literally.
Mazda designed the exhaust sleeve so that exhaust gases can get around it, hence, my statement about that particular fact earlier.
I bet there's more exhaust gas entering the leading edge of the exhaust sleeve versus the two holes on the "ceiling" of the exhaust sleeve itself.
The exhaust gas vector is more apt to enter that way.
Keep in mind that in most set-up's, there's also a scavaging effect downstream (from the other rotor) causing a negative pressure area that makes it even harder for the exhaust gases to enter those two holes.

If he's bitching about how much exhaust gases are getting past even with his plugged holes inside the exhaust sleeve, why bother plugging the two holes in the first place?


-Ted