I need to instal a second coolant temp sensor in the head. The new sensor is 3/8” NPT. My searching leads me to believe the mechanical sensor port on my 235 head is 5/8” straight thread. I’ve seen the available adapters to use that port. But that would leave me without a functional temp gauge.
Where in the head is there enough meat to drill and tap a new port? I’d go to the T-stat housing but that’s not recommended in the efi instal directions. Is there a mechanical gauge with an extra long thermocouple to reach the T-stat, that could be an option with Langdons housing.
Have you thought about a T in the existing port so you could run two sensors?
What EFI are you installing? I’m very much interested in EFI for my 58, 235 and would like to follow along with your install.
I have, I don’t think there will be enough space with the 2 sensor bulbs in a T configuration. I’m looking at a Holley Sniper. They have a 1.45” bore 1 barrel set up.
I was doing some planning for the Holley Sniper and thought I came up with a T that would work. That was a year or so ago and my memory is not the greatest anymore but luckily I saved everything I accumulated in a box. I’ll check later today and see if its there.
Is your space constraint due to air cleaner or other interference?
The biggest hurdle for me was going to be the intake stud spacing vs the Holley base boss mismatch. Do you have a solution for that?
Dan
35 CC Case 38 Chevy Pickup 51 3100 AD 58 3100 Apache Fleetside
I was doing some planning for the Holley Sniper and thought I came up with a T that would work. That was a year or so ago and my memory is not the greatest anymore but luckily I saved everything I accumulated in a box. I’ll check later today and see if its there.
Is your space constraint due to air cleaner or other interference?
The biggest hurdle for me was going to be the intake stud spacing vs the Holley base boss mismatch. Do you have a solution for that?
I don’t have any space concerns. I saw the base pattern issue. I’ve got some ideas but wont have a solution until I have parts in hand.
Tee fittings will give a false (low) reading, since the sensor will be out of the flow of coolant and the extension of the fitting will act like an insulator. The driver's side rear area of the head beside the valve cover flange should have enough thickness to drill and tap for a 3/8" NPT thread. Use pipe dope or brush-on gasket sealer on the sensor threads. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Tee fittings will give a false (low) reading, since the sensor will be out of the flow of coolant and the extension of the fitting will act like an insulator. The driver's side rear area of the head beside the valve cover flange should have enough thickness to drill and tap for a 3/8" NPT thread. Use pipe dope or brush-on gasket sealer on the sensor threads. Jerry
Comments: In common to all kits, the "gotcha" is induced noise (from coil, alternator, starter motor etc.) into the wiring harness and voltage spikes. Noise can cause out-of-the-blue weird events with engine performance so plan your wiring routing with this in mind. Voltage spikes (bad battery connection etc.) can turn the "brain box" into useless parts.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
The GMC engines of the same period used a similar, but different Thermostat housing where the temp sender was on the driver side. It will bolt right up to the Chevy head. I got one on Ebay years ago and haven't used it. I was going to use it for coolant heating to a Edmunds intake, but I went a different route. Check Ebay and you may find one.
