Max EGT? Options

[technicalninja]

Sounds great!
Thanks for the clips.

Couple of questions:

What's up with the 150 degree lower reading on cyl 1?

Just a fluke?

I've seen gauges "clocked" so when "all is right" the needles all point one direction, usually straight up.
I've seen clocked gauges that the numbers have been removed, just a black face with a red triangle that says "BANG" in the red. This was on a fully prepared 944 track car.

This is to improve rapid scanning for the driver.

First time I've seen a Speedometer clocked at anything but level.

Was that intentional?

Looks like 100 is straight up on that one.

I like your center console!

[ChrisFoley]

Just dying to know.

Delta across the CHT sensors?

Within 25F most of the time.

Did you see any evidence of any cylinder being significantly different than the others?

Not really, although before I installed turning vanes under my shroud, I saw lower temps at cyls 2 & 3.

Did the car have the racoon sized tube from the front during these tests?

That was only added in 2005 after being unable to keep the 12:1 engine CHTs below 400F on WOT runs. I implemented lots of air management ideas, but nothing solved the problem until I added forced air to the engine compartment. It didn't affect the temperature spread across cylinders.

I'm guessing that was the biggest improvement to the cooling system you did.

Considering the side benefit of more air for induction, yes.

Ever ingest anything?

There's a screen on the inlet at the front of the car. Lots of rubber tire bits collected there but nothing more substantial.

[mb911]

Cool comparison - 1350-1375 is where I run my Lycoming for best power. That is about 75-100F below peak. FYI, at sea level I flow about 18 gph to make 180 hp.

That holds amazing similar to my 200 hp outboard. Ain’t physics/thermodynamics/combustion efficiency a cool thing!

That’s right on. I use to do phone support for aircraft engines and once you got to 1450-1500 bad stuff was likely to happen . Turbocharged applications ran hotter but NA application your right on.

[gereed75]

Slightly OT but telling: My son was runnning an Audi SQ5 on the street (until it got stolen). V6 turbo, chipped. He had a phone app that could read every engine parameter that the computer saw and used for tuning.

One cylinder on that engine was slightly more prone to detonation than the others, #5 or 6. Maybe because it was adjacent to the turbo and slightly hotter, also at end of fuel rail, maybe tended leaner, whatever, but as it detonated the computer reduced advance in that cylinder only, not a lot. About halve a degree. That was enough.

Two points - they don’t use AFR. or EGT. They use individual knock sensors on each cylinder. And secondly they did not control it using fuel flow, they use timing.

That tells you a lot about balancing cylinders and what parameters are important and effective

So assuming your cooling system is up to par, and that is very important. And your mixtures are good (AFR correct) and no mechanical problems - then timing is super important to controlling CHT .

One or two degrees really matter. Too high and the ICP goes up, stress goes up, CHT goes up and you make LESS POWER.

[Root_Werks]

Usually run low 1300's on my O200 in cruise.

95% of the time, just old-school pull back mixture until stumble, back in a little until smooths out. Always by sound and feel, EGT's settle in the low 1300's. Feels good to know the EGT gauge isn't needed, but certainly nice to have.

For auto, would think it'd be useful to help dial-in a fuel system. Not really needed after that unless you race the car?

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[gereed75]

There is a lot more that could be discussed about running airplane motors and lots of old wives tale lore out there, some of which is dangerous.

Not the right forum for that beat up discussion

I am a disciple of Deakins whose much researched and proven by experiment knowledge is documented in his Avweb publications found here

https://www.avweb.com/ownership/john-deakin...elated-columns/


All aviation oriented but universally true for anyone who wants to understand better what goes on in a combustion chamber whether it is aircraft or automotive, and very transferable to our air cooled motors

Water cooling can tolerate and cover a bigger range of operating errors. It can also provide a more stable environment for optimum tuning, thus the disappearance of our “novel” addiction

I really need to get my EFI project going (again). Too many diversions!!

[technicalninja]

There is a lot more that could be discussed about running airplane motors and lots of old wives tale lore out there, some of which is dangerous.

Not the right forum for that beat up discussion

I am a disciple of Deakins whose much researched and proven by experiment knowledge is documented in his Avweb publications found here

https://www.avweb.com/ownership/john-deakin...elated-columns/


All aviation oriented but universally true for anyone who wants to understand better what goes on in a combustion chamber whether it is aircraft or automotive, and very transferable to our air cooled motors

Water cooling can tolerate and cover a bigger range of operating errors. It can also provide a more stable environment for optimum tuning, thus the disappearance of our “novel” addiction

I really need to get my EFI project going (again). Too many diversions!!

Thanks to everyone for the advice!

That page linked above is a KILLER resource!
I just "blast read" a couple of the articles...
Added that link to my favorites bar!

@ChrisFoley , thanks for the detailed response!
Your data was very helpful!

@gereed75 I'd love to discuss what you have in mind regarding you EFI project.
This thread isn't the place...
Do you have a build thread that I could look to?

I'm planning wild with a MS3 Pro. These ECUs can log SO many parameters it's like having a dyno built into the car.

[VaccaRabite]

Another question that popped up for me is:
Has anyone installed CHT thermocouples on all 4 plugs and what was the delta between them all?

I BELIEVE that cylinder # 3 runs hotter and is the most critical in the engine but...
I've never tested this myself!

I believe because EVERYONE else does.

What's the difference?
Is it 5 degrees or 40?
5 doesn't bug me.
40 does!
40 would make me want to try different things electronically to reduce the delta.

Injector pulse length, injector timing and ignition timing are the only easily applied adjustments IMO.

@technicalninja
I did that BRIEFLY on my old 2056 while it was carbed. I think I was using the same unit Chris was using. There was a group buy for them back in the day. I don't *think* I put it in when I was doing the Microsquirt conversion. I know from 2017 -2023 that engine ran only with the #3 lead.

It did confirm that #3 was the hottest by about 30 degrees - for my engine at that time. Be it tune (likely) or cooling air leaks (for sure) there was a marked change across the cylinders. That was 30 degrees delta from hottest to coldest. Cylinders were (from coldest to hottest) 2, 1&4, then 3. 1&4 ran pretty close to each other.

When I changed over to Microsquirt I went back to a Dakota Digital CHT on only cylinder 3. When I got my new engine last spring I did not even work the other cylinder heads for leads - only kept cyl 3.

If you want the 4 way unit, PM me and I'm sure we could work something out. I'm certainly not going to use it again and its just taking up space in my shop. Its back in its original box, waiting for me to get off my ass and list things for sale.

Zach

[technicalninja]

PM sent

Appreciate the additional data.

30 is enough to make me want to lower...

With the spread that you've reported and the order you reported I'm leaning towards looking at cooling system mods.

I wonder if Chris's new oil cooler (which gets rid of the factory cooler) can be put to use with changes to the passenger side air guides for improvement on that side.

Thanks again!

[technicalninja]

Thread took a turn I didn't expect...


Zach comes up with a super nice stand-alone unit that can run both CLT and EGT with 4 channels.
He won't call it NIB but it is.
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This is the unit.

Here's the readout at idle.....

When I first saw that I thought 'Damn, that's a nice-looking gauge, too bad it probably won't interface with a MegaSquirt...'

I still don't think it will; I'll be shocked if it can do CAN bus.

What it can do is either CLT or EGT and it does it stand alone!

I'm not sure if it can log yet, the manual is still AWOL but I'm hopeful.
Logging is the single most important feature to me, but this critter can be used to verify if the MS is reading the TCs properly.
I can use this to "test the test equipment" which is one of my proverbs...

I can also use it on carbed stuff which is the main reason I bought it.
I'm going IDFs first.
I already have them, 40s and 44s.

I was planning on ordering one of the small square box set ups anyway and Zach's unit is far superior IMO.
I'm happy I procrastinated in ordering that.

Zach's price was budget friendly!

TARGET DOWN!

And I helped fund a pretty neat Rabbit project a tiny little bit.

I'd, personally, "blow its brains out."

So, as well as answering my original question with multiple apex sources saying damn near exactly the same thing, I solved my "need simple CHT sensor before killer ECU" quite nicely!

This is a cool place!

Ninja Happy!
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And now for the DARK SIDE... (IMG:style_emoticons/default/devil.gif)

We have chickens.
Last year's flock got destroyed (14) by a neighbor's dog, we bought a flock of new pullets (supposed to be female) this spring.

Two of them transitioned...

Got BIG and MEAN.

Had to live in separate chicken coops; property came with two coops anyway.
Attacked my wife FAR too often.
I wasted the red one a couple of weeks back; he was the more aggressive and we'd hoped that not having a second rooster around would make the gorgeous white one calm down...

My wife loves her chickens; she didn't want me to kill the first one.
She wouldn't even consider EATING him, which was a downer for me as he looked delicious! (IMG:style_emoticons/default/chowtime.gif) (IMG:style_emoticons/default/chowtime.gif)

The white one went ballistic tonight, got her pretty good!

Gentlemen, I'm going to go STRANGLE MY COCK...

[VaccaRabite]

Something to consider...

Microsquirt (which uses an MSII ecu) only used the CHT for warmup purposes. Infact we hijacked the coolant temp sensor pin (CLT) on the Microsquirt ECU. For the CHT/CLT we used the stock location, not a spark plug. This mean that my CHT gauge read a bit higher then what the ECU saw. Which was fine, I just set my warmup enrichment and AAR tables for the ECU and had to divorce myself from what I was seeing in the cockpit gauge.

The new engine running Holley Teminator X is doing the same thing. Using the stock location for the CHT for warmup, and then I monitor the "real" CHT in the cabin with the DD CHT gauge using a K type on Cyl 3.

With the 4 Way you are getting, if you are using it for CHT you will need to do the same thing, as you won't have another spark plug you can put a K-type thermocouple on.

Zach

[technicalninja]

Something to consider...

Microsquirt (which uses an MSII ecu) only used the CHT for warmup purposes. Infact we hijacked the coolant temp sensor pin (CLT) on the Microsquirt ECU. For the CHT/CLT we used the stock location, not a spark plug. This mean that my CHT gauge read a bit higher then what the ECU saw. Which was fine, I just set my warmup enrichment and AAR tables for the ECU and had to divorce myself from what I was seeing in the cockpit gauge.

The new engine running Holley Teminator X is doing the same thing. Using the stock location for the CHT for warmup, and then I monitor the "real" CHT in the cabin with the DD CHT gauge using a K type on Cyl 3.

With the 4 Way you are getting, if you are using it for CHT you will need to do the same thing, as you won't have another spark plug you can put a K-type thermocouple on.

Zach

Yep, figured as much.

Update on the rooster!

Critter got out during his attack.
Was on the top of the coop last night, crowing his head off!
Anytime anything moved in the yard he'd crow.
3 am, you couldn't get within 75 feet of the cage without setting him off.
Unless it was very cold...

It was cold this morning when I went outside to deal with him.
White feather bomb detonation!
He'd met another critter!
I didn't have to kill my wife's rooster.

Karma is HUNGRY!
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[stownsen914]

It must have been 1300 degrees I was remembering, not 1200. Still a little fatter than what others report ...