Re: Engine temperature sensor - has anyone added one?
Posted: Thu May 28, 2020 10:36 am
Couple of comments in general.
First placement of add-on sensors in the Pinz, be it O2, Oil Temp/Pressure, MAP, EGT/pyrometer, etc.
will always be a compromise. Your retro-fitting a capability that simply was not designed in at the
get-go. So unless your planning on a major redesign it's gonna be a compromise and less than perfect.
Starting with O2 sensor, the compromise I made was placement on header for #2 and #3 - thus the average
O2 in the stream of 2 out of 4 cylinders. If you want the average of all 4 cylinders you would need to
redesign the hard coupling to merge both headers. With the trade-off I have it seems to be good enough.
I adjust ARF on the fly with my EFI controller setting to ~11:1 for peak torque for the trail, and to 13.5:1
for good fuel economy on the HWY -- the results are very noticeable. So I'd say it's in the ballpark despite
the trade-off. If I run ~ 10:1 you can smell your running too rich, and if I run closed-loop (not recommended)
at 14.5:1 it's just too lean. Is it perfect no. You do have to develop an experience base to mentally
recalibrate the readings to some degree.
The same is true for EGT, it's going to be a trade-off. Pick a spot close to the exhaust port, but more
important be consistent with placement of all 4 so you get a better relative reading between each. The
absolute value will not be 100% accurate. But what I find of value is the behavior, how they ramp in
value, if my experience of the hottest (#3) goes higher than expected does the driving conditions and
outside temp explain that or is there a problem. It's a quick way to know when you have a spark problem
on a given cylinder , or more unnerving, a cold laggard cylinder due to valve seat recession -- I had
that problem once -- was time for heads to be refurb. I see this as vital signs with with an experience base
that tells you a lot about the relative health of the engine. On my 712 I decided to go for only one EGT
on #3 the most notorious cylinder out of the bunch to watch.
Oil temp and pressure is more deterministic. You have one tapped hole to decide which way to go.
Pressure or Temperature. The stock pressure switch is better than nothing but it's basically an idiot
light. My 710 does have both T&P with an added drilled and tapped sensor port. I don't feel like going
that route yet on the 712. So I have to decide which is more important full range Pressure or Temp.
There are interposers that fit between the Oil filter and the base housing. Seems to have sufficient
clearance to get one in there. I might one a try if I can find one with 1"-12 thread, this is an example
of one I found but only 3/4" thread.
https://prosportgauges.com/products/oil ... 0851944588
First placement of add-on sensors in the Pinz, be it O2, Oil Temp/Pressure, MAP, EGT/pyrometer, etc.
will always be a compromise. Your retro-fitting a capability that simply was not designed in at the
get-go. So unless your planning on a major redesign it's gonna be a compromise and less than perfect.
Starting with O2 sensor, the compromise I made was placement on header for #2 and #3 - thus the average
O2 in the stream of 2 out of 4 cylinders. If you want the average of all 4 cylinders you would need to
redesign the hard coupling to merge both headers. With the trade-off I have it seems to be good enough.
I adjust ARF on the fly with my EFI controller setting to ~11:1 for peak torque for the trail, and to 13.5:1
for good fuel economy on the HWY -- the results are very noticeable. So I'd say it's in the ballpark despite
the trade-off. If I run ~ 10:1 you can smell your running too rich, and if I run closed-loop (not recommended)
at 14.5:1 it's just too lean. Is it perfect no. You do have to develop an experience base to mentally
recalibrate the readings to some degree.
The same is true for EGT, it's going to be a trade-off. Pick a spot close to the exhaust port, but more
important be consistent with placement of all 4 so you get a better relative reading between each. The
absolute value will not be 100% accurate. But what I find of value is the behavior, how they ramp in
value, if my experience of the hottest (#3) goes higher than expected does the driving conditions and
outside temp explain that or is there a problem. It's a quick way to know when you have a spark problem
on a given cylinder , or more unnerving, a cold laggard cylinder due to valve seat recession -- I had
that problem once -- was time for heads to be refurb. I see this as vital signs with with an experience base
that tells you a lot about the relative health of the engine. On my 712 I decided to go for only one EGT
on #3 the most notorious cylinder out of the bunch to watch.
Oil temp and pressure is more deterministic. You have one tapped hole to decide which way to go.
Pressure or Temperature. The stock pressure switch is better than nothing but it's basically an idiot
light. My 710 does have both T&P with an added drilled and tapped sensor port. I don't feel like going
that route yet on the 712. So I have to decide which is more important full range Pressure or Temp.
There are interposers that fit between the Oil filter and the base housing. Seems to have sufficient
clearance to get one in there. I might one a try if I can find one with 1"-12 thread, this is an example
of one I found but only 3/4" thread.
https://prosportgauges.com/products/oil ... 0851944588