Something sounds amiss... you are running a 180* thermostat but your engine runs below the thermostat temperature.

The t-stat should keep the coolant flow restricted to build heat into the fluid medium... and maintain the 'set' tempersature. So for your engine to run below the 'set' temperature... there has to be something that is allowing the coolant to continue to flow even under the 'set' temperature. I'm guessing that your bypass in the manifold/pump is being used... but I would'nt expect it to flow so much that it would drop more than about 10*F maximum.

150-160*F (20-30*F) is a big drop for for a closed system running a thermostat. I wonder what it would do with a 195* in it ??

I agree man...I swapped out the thermostat thinking the same thing. Does exactly the same thing. I have checked the T-Stat with my gun and it opens right at 180. I have also checked the temp sensor and it's dead on. I have noticed that the t stat can be open with coolant temp at 180 at the t stat housing and the coolant is still only 165 in the back of the intake. That is in the garage after warm up and the intial opening of the stat. I let it warm up for 5-10 minutes this morning and drove down to cars and coffee and it still hadn't fully warmed up. that 15w40 rotella must be some good chit. :unibrow: I am going to verify my oil temp is above 180. If it's not I'll change over to a 195 stat for winter to bump up the oil temp.

I guess it's time to do a little more investigation to see if the t stat is open at 150 operating temp.

You using a "Robertshaw"... or an OE style t-stat ??

I assume you mean high flow....I had a milodon 180 and now a Mr. Gasket 180. I'm not running the water pump bypass hose. Wonder if that could be a contributing factor.

Happy with my AFCO.. it only has one fan and I had zero heat issues at the Optima challenge.

Two fans are a great idea though, especially if you have air conditioning.

i have a be-cool in my impala, a howe in the malibu and a ron davis in both my 65 mustang and my 32 roadster (the 454 deuce :-)) and for quality and wow factor id say ron davis.. but both the howe and be-cool function flawlessly, so from a cooling standpoint i dont have any donts... but i sure like the ron davis units, especially the integral fan option... automotive porn!

GRIFFIN - complete rad built n house and amazing quality!

for any of you guys that may have classic vettes or are looking to build one, DeWitts makes the best ones out there. I've never had an issue with his setups and I've used them on C2-C4 cars. They cool very well on the C2 and C3s which actually have cooling issues.