67Skylark

Looking for a temp sensor to control an idiot light. Need help deciding what would be the proper overheat limit?(RT Head Port) Anybody know a partnumber that would screw directly into the M12X1.50 without an adapter?

Also min oil Pressure for light?

1981TA

iTrader: (7)

I'd pressure below 25 pounds is a sign of trouble. What about getting gauge with a programmable warning light?

soundengineer

iTrader: (16)

oil pressure below 25psi is not a sign of trouble....

I have around 20~25 at idle, comes right up to 40 at cruise...


all depends on how tight or loose your motor is built, and a loose motor wont have much pressure at idle...

the general rule is 10 psi per 1000 rpm...

the Stock 4th gen F-body oil pressure light doesnt come on until 12 psi if I recall correctly



as far as an overeat temp...
really it depends on your setup
the stock motor runs around 230~240* operating temps(its a fuel economy and emissions thing... GM figured out they get the best of those two around those temps)

I like to see temps in the 210 ish range...its where the LS motors make the most power...


I wouldnt take an aluminum head much past 260*, but an iron headed 350 I wouldn't have issues with it until 270~280*
thats where you start to see so much expansion that you get head gasket issues and start seeing motor issues

also, above 260* you are going to start having coolant system pressure issues...everything starts to boil.....builds lots of pressure, and things start to give out.

Pop N Wood

iTrader: (1)

For oil pressure you could buy an oil pressure fuel pump cut off and hook that to a light. Mr Gasket sells one pretty cheap. I think they come in at 15 PSI. I run one with my carb.

for water temp no one makes a temp switch with the metric threads. Painless sells a radiator fan kit with the proper size switch, but they don't sell the switch outside of the kit and the trip points are pretty low.

If you are running a single speed fan then you could probably probably wire up the high speed circuit out of the computer to run a light.

Or if you want to get creative you could plumb a 3/8 npt sensor in someplace.

67Skylark

So 255 range on the temp, need s sender that supplys a ground or two wire that makes contact at 255

For the oil maybe a warming light around 15-18 psi that would supply a ground.

Any ideas for partnumbers?

I plan to use bluetooth off the OBDII port on some sort of tablet when running around but would still like a hard wire backup.

ls1nova71

iTrader: (4)

This is a cool idea, then you could change the tune to whatever temp you feel is too hot to have the light come on.

As for oil pressure, I just used the factory one for my Nova, drilled and tapped the original sender for it to fit. My gauge is tapped into the bypass block so I have both.

1981TA

iTrader: (7)

Good thought about the clearances. Mine is pretty tight, running 35 PSI at hot idle. I have three water temp senders, and the one that triggers the fan is plumbed into the heater hose flowing out from the water pump.

67Skylark

Well no real good solution, so here is what I ended with.
I couldn't get the protection I was looking for easily so I decided to just hang a couple of gauges off the bottom of the dash again; I have had them on and off several times in this cars history.
VOD makes a 250F sender that includes a warning light output at 230 +/-5 part number 323-100 ($42) this along with Street and Performance 12M to 1/2NPT adapter ($20) will run the gauge an idiot light.
As for the oil VDO 80 psi Sender part number 360-019 has an 8 psi warning light output with 1/4 NPT treads that will be tapped into Oil cooler bypass plate.
Thanks for the input, I may try to follow up with the fan output to control the temp light once the car is running, At this point I'm in the dark about the programing of the E38, but if that would work there are pressure switches with just about any setting you desire for the oil light.

Hal StClair

iTrader: (3)

I had the same issue with finding a idiot light sensor. I found that an early BMW (1987 535i) used a 120 C (248 degree) dual gauge,light sensor with the right thread size. I just picked one up but haven't installed it as I'm out of town for the holidays. The only issue it may have is the length of the probe. I'll know within a week and post back.
I just used an 1/8" pipe idiot sender for the oil light mounted in the bypass fitting above the oil filter. Hal