The eBay add says the gauge can be calibrated via the rear panel and is cold junction compensated. In theory it should be very good. I use a VDO gauge but unfortunately, they’re no longer available, CSP have a similar one but it certainly isn’t cheap. https://www.csp-shop.com/en/electric/cylinder-head-temperature-919-085-113c-30799b.html
so it does! Although I’m sure it’s not mentioned on the instructions, and there is nothing on the back panel that I recall. I will look closer on Monday
If you dont mind square ...and any9ne is looking.. http://www.skydrive.co.uk/proddetail.asp?prod=CH005 Sent from my SM-G930F using Tapatalk
Ok, some more tinkering on this with the trusty bbq gauge... With the bbq probe touching the thermocouple, as the engine warms up, the bbq rises faster than the thermo, and when bbq is reading 100, the thermo is reading 72. Then if I turn the engine off, they both read the same within seconds. If the engine is then started again, the thermo gauge immediately drops back down again. So, i reckon the fan is cooling the stem of the thermocouple when it’s running, giving a false reading. There is about 10mm of the stem exposed, before it’s covered in what looks like heat shrink tubing, then the stainless stuff. There is no provision for adjustment via the back panel, and no mention of it in the instructions. So, if anyone was thinking of fitting one of the above cheapy gauges, You might want to consider insulating the exposed bit of the stem with something suitable Or just poke your head with a £5 bbq thermometer
I've fitted a bbq probe into some thermal paste through a blanking screw in the CHT probe hole that the EFI would use in the head. Seems to work ok used two of the six probes you get on heads, stuck another in a bit of 5mm brass tube to make a dipstick sender going to leave another for a "proper" CHT couplerlocation to get a temperature adjustment reading and one more for ambient air temp.. all bluetoothed to the phone .. could try to stick one in the exhaust somehow to get EGT? but it is only a van at the end of the day Sent from my SM-G930F using Tapatalk
I have a similar aircraft gauge in my bus. I think it looks cool but typically these gauges compensate for ambient temp. You can also do two cylinders. I have one that is hooked up properly. The other is JB welded to a fin. It tells me if the engine is running. I guess you could get 2 and do all 4 cylinders... build a panel like a Lancaster bomber and hire a flight engineer to watch them. AC gauges aren’t too crazy expensive until you get into navigation stuff.
Mine reads low in the summer when I turn the heating off and spill the hot air at the cold junction. I'm thinking of moving it into the engine bay where it's much cooler!
I was only really wanting to see how well the upright fan cooled the type 4, rather than a permanent fitting. Now I know how the guage performs, it seems that the hottest I got it on a hot day was 125 ish, which suggests it cools ok. I will probably now confine the ugly arsed attention seeker to the round filing cabinet, or Chuck it under the back seat until paranoia gets the better of me again ..
Might not be the problem , but the DC resistance between the engine and the vehicle chassis could be making the voltage from the thermocouple drift off when the engine runs and charges the battery - it is not helped by the fact that the thermocouple produces microvolts of signal (about 40 microvolts/degree C). One side of the thermocouple is connected to the head, then the cable runs off for some distance to another place where the ground from the display is connected. If you have a different voltage at each ground , current flows in the thermocouple cable that shouldnt be there. Which offsets the reading. I had to completely insulate my thermocouples from the head to stop this problem on my setup..
