Run in stand/dyno build.

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Anyone here run "K" type thermocouples on our engines?

I just ordered an amplifier box to hook up two thermocouples to my Datamite and none of there's will work.
Terry Thy run them on out board eng all the time.
I had 2 on my Merc 2.5L.
There are many stand alone EGT systems you can get pretty cheep.
 
I ran several over the years. The earliest was as a sensor for a needle control system that used EGT as an indicator of mixture setting on a K&B 7.5. Pictured below are two setups for sensing EGT on an Eagle Tree data logger. I embedded the thermocouple in a dead glow plug body for easy removal.

Lohring Miller

Crackerbox EGT.JPG3.5 EGT setup.JPG
 
I ran several over the years. The earliest was as a sensor for a needle control system that used EGT as an indicator of mixture setting on a K&B 7.5. Pictured below are two setups for sensing EGT on an Eagle Tree data logger. I embedded the thermocouple in a dead glow plug body for easy removal.

Lohring Miller

Real (model) world experience, just what I'm looking for.

Looking at the Pyromation catalogue here https://www.pyromation.com/Catalog/ProductCatalog.pdf I see a bunch of information in the 1st fifteen pages or so.

I'm thinking a 1/16" "exposed junction" with a 316ss sheath should work for the exhaust (pg. 12)?

For under the plug Mike Rapold used a solder lug crimped to an open wire thermocouple, any experience with that? Currently I'm using a thermistor with the Eagle Tree (resistance based) but it's not compatible with my dyno box.

Any idea hot hot the exhaust runs on our motors? Got any part numbers? Thanks!
 
Terry,
I can't speak for our little engines, but a modern day fuel car runs 1250-1300 degrees, about 2 1/2 inches from the header exhaust flange. I suspect you'll be around 900 degrees or less.
 
Terry,
I can't speak for our little engines, but a modern day fuel car runs 1250-1300 degrees, about 2 1/2 inches from the header exhaust flange. I suspect you'll be around 900 degrees or less.


Thanks, good information.

I came across a post on another forum where a 40 size pylon racer measured 480-490C in the header pipe so that's right at 900F as you mention.

We might be a little higher running nitro but they run a lot leaner than us.

I see Eagle Tree had an interface board and thermocouple probes at one time:

https://hobbyking.com/en_us/thermocouple-expander-w-exhaust-gas-probe-1.html?___store=en_us
Might try to find one of these somewhere...
 
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Terry have you ever used the Eagle tree EGT set up with the amplifier board to hook the k couplers to?
I just looked and see thy are closed for good now.😢
 
Terry have you ever used the Eagle tree EGT set up with the amplifier board to hook the k couplers to?
I just looked and see thy are closed for good now.😢

They are only compatible with the old data logger, not the eLogger I'm now using. It uses resistance based thermistors, I've been using one of these under the glow plug:

https://www.vishay.com/docs/29195/ntcalug85am6.pdf
 
Thy are a amplifier.
Not sure about what the out put range or signal on the out put but you may be able to interface it with the soft wear you are using for the Dyno.
You have one of the boards?
 
1610661413419.png1610661469572.png
I gust drilled a hole in the header half in the eng end flange and stuck this in the hole.
Crude but effective.
Depending on the amount of Castor in the mix if any the EGT's will fall between 700 and 800 on a good rich needle making power and not taking plugs.
The more Castor you use the closer to 700 you will be.
Be leave me at over 1200 your piston will be liquid very soon.
Foley go a head show him the pic will YA?????????
 
View attachment 287072View attachment 287073
I gust drilled a hole in the header half in the eng end flange and stuck this in the hole.
Crude but effective.
Depending on the amount of Castor in the mix if any the EGT's will fall between 700 and 800 on a good rich needle making power and not taking plugs.
The more Castor you use the closer to 700 you will be.
Be leave me at over 1200 your piston will be liquid very soon.
Foley go a head show him the pic will YA?????????


Trying to find one of those with their thermocouple, I'd like to play around with it and see what it outputs. I have a feeling it's just an amplifier similar to the unit I have coming from Performance trends that takes mV from the thermo's and ups them to 0-5v for the software.

You must have one of these?

https://www.modelgasboats.com/index...le&id=87:eagletree-bdr&catid=55:miscellaneous
 
Trying to find one of those with their thermocouple, I'd like to play around with it and see what it outputs. I have a feeling it's just an amplifier similar to the unit I have coming from Performance trends that takes mV from the thermo's and ups them to 0-5v for the software.

You must have one of these?

https://www.modelgasboats.com/index...le&id=87:eagletree-bdr&catid=55:miscellaneous
I have 2 of them and also one V5 set up. Have the LED display for the V5 also.
I bet if you look on flee bay you can find one.
The coupler is nothing but a K style. all K styles work the same no mater what the size.
You can drill a SMALL hole and just stick it in the header.
Gust drill a small hole in the ex coupler and stick it threw it and in to the hole in the header.
It will seal it up and hold it in place.
 
The long ago remote needle system used 260C for the EGT temperature set point. I don't remember and can't find the data from the two pictured sensors. I use between 450 and 550C for pipe design formulas so the EGT should be higher than that for gasoline engines. Glow engines should run much cooler.

Lohring Miller
 
The long ago remote needle system used 260C for the EGT temperature set point. I don't remember and can't find the data from the two pictured sensors. I use between 450 and 550C for pipe design formulas so the EGT should be higher than that for gasoline engines. Glow engines should run much cooler.

Lohring Miller

How did the automatic needle system work?

I've been thinking about trying something like that, I think if we could control the needle setting for our nitro motors better we could run closer to the edge and not go over center.

I think Dave was messing with something like that also?
 
How did the automatic needle system work?

I've been thinking about trying something like that, I think if we could control the needle setting for our nitro motors better we could run closer to the edge and not go over center.

I think Dave was messing with something like that also?
The first needle system I saw was Ed Baker out in Maryland in the early 1980’s. With slow servos and other issues he gave up on it. If I remember karts were using EGT sensors at that time already which would suggest that motorcycles were also.
Thanks John
 
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