Camivette

Which sensor do you use since the old sensor is 1/2" npt and the vortec port is 3/8" ?

BKbroiler

I used the stock, original sensor and installed it in the intake manifold, near the thermostat.

'75

I used the original sender and enlarged the hole in the head.

scottyp99

Yep, there's more than one way to skin a cat! I'm thinking about moving my sensor up to the intake just because I don't like that wire so close to the header. Good luck with however you decide to go.


Keep the shiny side up!
Scott

Camivette

The engine is assembled and already in the car so enlarging the hole at this time is not an option. The simple solutions are sometimes right in front of you.
BK- Everything good with your relocation? That would put the sensor above the top of the radiator. Just askin.....

jcloving

It would be interesting to install both and see the temperature difference...if any.

scottyp99

My guess would be that the difference would not even be close to how inaccurate the stock gauge is. It's really just there to let you know if there is a drastic change in temperature. I wouldn't worry about it. It would be interesting to compare them, though.


Keep the shiny side up!
Scott

gkz

Duralast TU66

http://www.autozone.com/autozone/par...artNumber=true

PeteZO6

The problem with that approach is the sender is most certainly not calibrated to the gauge. The result is the gauge will not read correctly. There is a lot of information about this subject on the Forum. The best bet is to do as BKbroiler suggested and mount the original sender on the intake manifold. That's how I solved my similar problem and the gauge reads just like it did with the original iron heads.



You can see the sender sort of hidden under the fuel line.


Pete

Scottd

Use a brass NPT pipe adapter to fit. DO NOT put that sensor anywhere other than on the intake. I tried to clean up my engine bay and ran the sensor to a plug on one of the heads. HOLY SHI+ the head temp is WAY higher than the coolant temp at the thermostat housing, and it varies wildly with engine operating.

69vette19467

PeteZ06: Where'd you get that accelerator cable bracket shown in your pic? I need one. Thanks.

PeteZO6

OEM. Came with the car.

Pete

Camivette

gkz You don't happen to have the ohm readings at various temps for this sender do you? If the readings at 200 deg are close it will work fine

peteZ06 your sender is where my heater line nipple goes. I have two ports by 7 or 8 cylinder I can use. I like taking the temp in the head ports because it does give the highest reading. Did you paint your valve covers or did they come that way?

Thanks

gkz

You're correct; they don't line up exactly. Here's a local experiment I did comparing the stock unit to the 'other' one. You can see the difference in resistance at various temps. I haven't reached that point in my build yet to see how the gauge registers.

PeteZO6

Do a search for sending units and gauges. Roger did a lot of work documenting the different senders and gauges and what was compatible.

You say if readings are close, it will work fine, yet you say the head readings are higher than the intake readings. Not so. The coolant flies by the sender so fast it doesn't matter if it is in the head or intake. The correct sender for the gauge in the intake is more accurate than a "close at 200°" wrong sender in the head.

The valve covers are C4 magnesium and are painted, you cannot polish or plate magnesium.

BKbroiler

Just getting back to the location issue. I've had the sensor in the intake for years. It seems accurate. I fill my system thru the tstat location so the area where the sensor is located is flooded.

MotorHead

Yeah so do I

Frankenvette

Installed Vortec heads back in 2000. Went to the local hardware store and basically searched through their brass fittings assortment until I found one that fit the vortec head (male end). I then combined several more brass fittings so that I ended up with adapters that allowed the engine temp gauge to mate with the vortec head. I have my electric fan temp gauge connected to the manifold. Never had an issue with either.

carriljc

many thanks

gkz

You're welcome; please post results of your temp gauge readings. I'm not there yet; thanks...