My engine is coming back next week from the shop hopefully all rebuilt and ready to go. I went with a Performer RPM intake and while taking the waterneck off my original intake today I saw the original thermostat that's been on the car since I bought it in 1982. I'm sure it is not the original but was surprised to see what it was:

ROBERT SHAW CONTROLS COMPANY 330-F 160 degrees

Shouldn't this have been a 180 or 190 degree thermostat?

Just curious. smile.gif

Yep you are right, should be a 180 or 190. :rolleyes:

You can get different answers to your question. For me, in my non-computer cars, in my climate, the 160 is by far the best. All four of my non-computer cars have 160s in them. Within certain limits, the cooler the engine is at operating temps, the better it is.

For older, non-computer cars, there isn't any "supposed to be" temp for the t-stat. That's why there's a range of temps available. BTW, Robertshaw is considered one of the very best t-stats on the market.

Thanks guys. So basically with the new rebuild(my first) I'll really have to wait and see what the engine likes? What's a good starting point? Is it best to ask my builder?

By all means, use whatever your engine builder recommends since he is the one who has to stand behind the engine if it grenades. Otherwise, I'd put a 160 in it.

FWIW, where newer cars get new eproms(performance chips) or re-programmed(Hypertech etc), they recommend a 160 degree tstat for best results from the chip or re-program modification. It sure made a difference on my 95 Vette and 96 Impala SS by adding the 160 after Hyperteching them. That's on cars that have 195 degree tstats from the factory. Makes me think that a 160 just might have some good points.

Beg to differ that older non-computer-controlled cars don't have a "supposed to be" thermostat spec. My 1972 Plymouth Valiant operators manual on page 45 says"...all models are equipped with 185 degree thermostats". "The use of a 160 degree thermostat is not recommended." I'm not smarter than the guys who designed my cars, so I follow their recommendations, and especially pay attention when they say: "not recommeneded".

No different for Chevy engines because: increased cylinder wall wear and sludge accumulation in the engine are associated with lower engine operating temperatures i.e. coolant temperatures.

My $0.02

Just to respectfully chime in. graemlins/clonk.gif

I highly recommend at least a 175*F. While I respect the advice you are getting here on this subject, the facts that just about every engine that I know of came with at least a 175F thermostat and many in the over 195! This would include high performance applications as well. The 160*F models are aftermarket applications only and why they are recommended is beyond me?

Simply put, operating temperatures (water jacket) of over 175*F aid in the vaporization of fuel and of moisture that collects in the engine especially in the oil! This rids your engine of water on short and medium trips between runnings. Lower thermostats cycling points will hinder this wanted feature of the higher temp thermostats and actually cause oil to degrade faster in your engine due to the moisture by-products. Most oil companies want at least 175*.

Also, a lower thermostat does NOT mean that the engine cooling system is better equipped to handle heat either if that is what your mechanic is thinking? The thermostat is not a functional part of the ability of the system to cool per se.... just sets the boundries.

But, it's your engine and you have to live with the engine builder.

Thanks for the advice gentlemen. I'll be calling my builder tomorrow to find out his recommendation. graemlins/thumbsup.gif