tmask1

I recently replaced my intake manifold and the new one only has 3/8 npt threaded holes, does anyone have any suggestions for a compatible water temperature sender that will fit?
Thanks

Rescue Rogers

What year is your car. I have a 68 and put a 81 sendor in it because I didnt want to machine the head ((68s had the sendor in the head and these are new aluminum heads) and it never read properly. I even had bought Willcoxs adjustable reistor and got it to read correctly at 210 but it didnt read correctly above or below that reading. The linear input from the sendor didnt match the gauge.

Willcox can machine down a correct year sendor to fit, which I have and the dash gauge now matches the mechanical gauges I have in the engine compartment, but you will be paying for the labor plus the sendor. Very worth it if you dont want to disassemble a motor to do the machine work

You may want to just get a 1/2inch NPT tap and machine the hole to the correct size. If you go that route, you need to know that you only go about half way down the tap because of the taper. Or just go to a engine machine shop, it cant cost too much if you bring in the bare intake, maybe $30 to $40 bucks.

MelWff

you have a 1968 in your profile but make no mention of which engine. Are you sure the sender isn't supposed to be in the drivers side cylinder head?

carriljc

Write to Willcox, or see their website, and get both the sender and the adjustable resistor they recommend.

That being said, on the 68 the temp sender should be in the driver side head. Do you have your original heads with the big sender hole? It doesn't matter a whole lot, I installed my large temp sender in the intake manifold (mine had the big hole in the intake manifold) and I dialed it in with the Willcox adjustable resistor (it's fantastic- get it either way). My gauge tracks wonderfully with my digital temp indicator on my EZ-EFI.....

What intake manifold did you get that has 3/8" holes? I'm curious because all the spares I have (3) have the large holes near the thermostat outlet..... even my Ramjet 350 has the large holes near the thermostat outlet.

PS- I actually have a 3/8" installed on the driver side head to experiment with one of these days and see how it works with my Willcox adjustable resistor(did I say it's wonderful?)...... I bought it to see if it would work with my gauge before I decided to just get the adjustable resistor--- so it's still in there.

Rescue Rogers

This guy was having sendor issues of another kind but I listed the willcox site if you need the tech vids. I had bad luck mixing different year senders to gauges

https://www.corvetteforum.com/forums...post1599592615

jackson

in head may be best.

also ... a viable option is to use a different water neck aka thermostat housing ... they're available with 3/8" and or 1/2" NPT holes.

titanle

Good information! I'm having the same issue with my 68 but the engine is an early 70s sb350. The temp sensor reads high, its threaded at the top front driver side corner of the intake manifold. I was going to buy a 68 replacement but I don't think that's what will work in my situation either.

Rescue Rogers

if its high across the board, then get Willcoxs adjustable resistor to calibrate it. Its a great piece of gear

titanle

Thanks!

0Willcox Corvette

The 3/8 NPT senders can be found at this link
https://willcoxcorvette.com/catalogs...q=3%2F8+sender

And as mentioned above I'd still install the adjustable resistor on the gauge so that you can match the gauge to the sender.

You'll find them at this link :
https://willcoxcorvette.com/catalogs...djust+resistor

Then if you go to our tech page. repairs.willcoxcorvette.com you'll find this information on how to install it including a video.

http://repairs.willcoxcorvette.com/?...djust+resistor

Willcox