Cylinder Head Temp Sensors
 

As the 3.0 litre SC engine we have is proving troublesome and needs a rebuild it seems like a good idea to try to convert the CIS to an EFI and I have been looking at various options.

I have been told by some guys in the UK that the Megasquirt system has problems with air cooled engines but there are several posts here on Pelican that seem to have dealt with this in a number of ways.

The 3.2 CHT sensor looks effective but I don't want to change heads.

Is there an effective way of fitting a CHT sensor on a 3.0 litre head or is there a better way of monitoring warm up.

Thanks

Grady Clay has previously posted about installing thermocouples into each head by drilling a small hole and retaining the thermocouple with a roll pin (and epoxy - if I recall correctly) which allows the thermocouple wires to pass through the center of the pin.

I've been using a megasquirt on my 3.3 turbo using a 3.2 CHT sensor for about 5 years with no problems. Just find a spot on the head out of the way of cold weather (under the shroud) to attach it (carefully drill a mounting hole in a fin if needed). I like it better than using the oil temp sensor for fueling accuracy.

I machined my stock turbo #3 head in the same location as a 3.2 head to accept a 3.2 temp sender. Works just fine. I,m also using a Megasquirt system.

Used a Bosch sensor on my SDS EFI like other before

http://forums.pelicanparts.com/uploa...1322037832.jpg

Another pic

http://forums.pelicanparts.com/uploa...1322038003.jpg

That look great - Thanks for the input.

Aircraft 3.0L heads have a spot for a temp sensor. They are the same as automotive heads other then that.
If you need one I might be able to scare one up.

Resurrecting an old post: Two Rivers - Do you have a pic of where the CHT sensor got installed on those 3.0L aircraft heads?

How is this setup in Megasquirt?

Lifting this thread.

I want to install 2 cylinder head temp sensors, 1 per cylinder bank. What type of gauge have you guys used and where did you place it? Looking for some inspiration.

I was hoping to find something that could replace the clock.

Johan

Why, might I ask? EFI only needs them for warmup purposes. Are you running the other to a gauge?

Not running EFI, but running carbs. My mechanic suggested including two sensors as an extra safety measure.

Johan

Westach makes a nice and affordable 2-1/4" dual CHT gauge that uses type J thermocouples:

Westach

I removed my ashtray and mounted one of these plus a voltmeter in its place.

Thanks! Hadn't heard about Westach.


If I can't find something that fits where the clock sits, I was thinking ashtray or radio delete.

Has anyone modified the Fuel/Oil gauge and used it as a Temp gauge?

Johan

+1 on the value of EGT sensing as an easy way to identify a misbehaving cylinder. Combining EGT with CHT would be the killer app for our air-cooled motors. Check this out:
12-Channel Digital EGT and/or CHT Pyrometer Gauge Display

I'll shamelessly plug the AEM thermocouple interface/amplifier I'm currently selling.>>>

FS - AEM Thermocouple Interface/Amplifier

Guaranteed <1% accuracy at full scale...kind of important... ;)

I bought it when using an ECU that didn't have this function built into it natively (my new Syvecs can accept K-Type thermocouples directly into the ECU). The AEM unit has 4x input channels (I only used 2 of the channels, an EGT on each bank on the secondaries), then fed that output from the AEM into my ECU as an analogue input. Worked like a charm, no setup and it comes with the voltage vs temperature charts so you can calibrate the ECU. Uses K-Type thermocouples. In as-new condition, aside from not coming with the 12w Deutsch connector which we needed for my install....easily available pretty-much anywhere.

(Can also output data as RS-232 for data logging into a laptop - I am half-wondering whether to keep the unit and use it to monitor "whatever", as-and-when I need to....all sorts of uses that it could be used for on a more temporary basis; stuff that you may not need to monitor on an ongoing basis.)

Hoping you got your answer and others can chime in on a separate but related question...

How does the cylinder head temperature correlate to the engine oil temperature?

Reason I ask is because I'd like to program my front-mounted engine oil cooler to turn on when the oil temperature reaches a certain number (>210-220F). However, I would need an temp sensor somewhere in the circuit, which I'm having trouble tapping into cleanly. If the CHT somewhat correlates to engine oil temp, I'm thinking just use that as sensor to trigger oil cooler fan. In other words, does 250F CHT correspond with 210F engine oil temp generally speaking?

The engine oil temp wouldn't help with tuning your motor due to the amount of time it takes for the oil temp get up to adequate levels.

Is this bracket available for purchase?

No, DIY part, but easily self made. Aluminum U-Profile or block with cut-out and thread. No rocket science.