Internal thermostat opens partially - ~2/3 - toss?
 

Wonder what y'all think about this. I've asked locally and gotten opinions on both sides.

Have been chasing an overheating problem. I know my mixture or ignition is part of it, my CO is like 1.8%. That should be easy enough to solve. However, while covering my bases, I pulled the internal thermostat to check it out. It seems to function properly, it begins to crack around 140 deg F and stops opening at around 185 or 190 deg F. However, it only ever opens about 2/3 of its 'window'. Took it up over 200 and it did not open any more. Is this restricting flow to the cooler and costing me potential cooling capacity?

Dave,
I would start with the mixture and go from there, 1.8 is very lean. I try to eliminate every possibility before throwing money at it.

Are you going to RR3?

Paul

Hi Paul,
Yep, I'm going to RR3. At this time it looks like I will need to work Friday so I'm planning to fly in Friday night. Dustin and Tim should already be down there so I'll ride home with them. I can't wait!

I've got the engine out right now doing some work to it. While out I'm trying to do a few things to maximize cooling, like doing the cooling tin mod and changing pulleys. The Targa does not have a front cooler so I'm trying to maximize cooling at the back of the car. If I am leaving additional cooling on the table by installing a worn-out or malfunctioning thermostat, I want to replace it now while it is easy to get to. This is on the '76 CIS that is a PITA to access in situ, not the '72 MFI car.

Dave,

I am cheap when it comes to buying parts; BUT, if you are cutting off 1/3 of the flow through the system, you are also risking not oiling the rod bearings enough right?

Replace it, you are already over budget anyway:D

I don't think there would be any oiling issues, as any oil blocked from entering the cooler would just be bypassed. At $129, I don't want to replace this thing if I don't need to do so.

Thermostats for a modern car like that (not SWB) are cheap, replace it.

Beg the money from someone and get that POS out of there! 100% or nothing!!

Best!

oh, just ignore me I am sick this week.