So the previous owner put in a 160 thermostat in the car (1979 L-82). I have replaced almost the entire cooling system since I bought the car, I definitely don’t have any overheat issues, even sitting in traffic on a warm day I’ve never seen the temp get above about 170. So my question is should I go to a higher temp thermostat? Is there any benefit? Or should I not even mess with it, I consider myself lucky to have a corvette that runs so cool.

 

There is an old saying: Let mean, grumpy, snarky, biting, sleeping dogs lie.

Its fine.

 

It doesn't matter what temp the thermostat is because you can just raise the fan turn on temperature (electric fans)

if you have a mechanical fan and the temp is sitting 160-170*F then yes I would do something about that. Either go electric and turn them on at 185 and off at 178*F for example,

Or... Hmm not sure what else you can do besides change the thermostat again. Which like the above poster pointed out is kind of silly to do all that work for something so small.
I mean. It depends on the application at that point. If you daily driver the car, or have a very expensive engine, or need a reliable cold-start machine, you might want to do something abo ut it.

If the car basically sits alot and rarely runs and when it does, doesn't go far, etc.. then it wont make much of a difference I guess.

 

Original fans, mechanical and electric. It’s not really a problem, just wondering if there is any benefit to running a warmer thermostat

 

No. It was a "Smog Thing".

Just my opinion, but the sooner a system starts cooling the better off you are. Mine does not wait for 180 or 190. It starts at 160. Never stays there anyway.

 

Low oil temp is associated with increased engine wear.
Because coolant temp is sometimes involved with holding down oil temp, it can also be an influence.

Please see more:
https://www.corvetteforum.com/forums...post1599613263


higher temperatures (compared to say 160*F) improve engine efficiency, improve economy, improve power
https://www.corvetteforum.com/forums...post1599588152

 

The only 'benefit' of installing a higher temp T-stat would be that the engine will warm up to the T-stat's rated temp quicker than with a lower temp unit. If you aren't driving a cold car in ZERO degree (F) weather, it will make no difference at all.

In warmer environments, I prefer the lower temp T-stats simply because it takes the engine a bit longer to heat beyond the T-stat temperature. Yours is just fine....

 

Low oil temp is associated with increased engine wear.

That's a true statement. However, its referring to those cold, cold, below zero January mornings at start-up and first few miles.

I find it hard to believe oil temp at 160 contributes to wear more than 180-200.

 

In the 80's the factory coolant temp was what, 180? 190?
In the 90-00's factory coolant jumped to around 212*F regularly
00-10's it went up to 210-230*F
10-20's it is now around 220-240*F

As technology and oils improve, higher temperatures yield benefits. This may not be true for older engines, all the time, but it certainly reveals a trend and is worth investigating.

 

That’s exactly what I was trying to remember, I had read an article once how proper engine temp is a good thing, that’s why I was thinking that a 160 thermostat might be a little too low.

 

It? You mean me? And I am not referring to cold below zero starts. Its every cold start, because even in Florida the starting temperature is 80*F which is easily 100*F below where it needs to be. The majority of engine wear is said to occur during cold-start (80*F starts and -30*F starts). This conclusion is drawn from the statistical relevance of vehicles around the country, i.e. vehicles in colder places tend to go as many miles as vehicles that cold start in warm climates (150-250k is typical?) Whereas the engine that last longest (350,000+ miles) are usually driving long distances without being shut off (no cold-restarts). Whether in 'cold' or 'warm' climates these stats seem to be true.

 

The reason that there is such a potential disparity between 160*F oil and 200*F oil is a couple reasons:
1. the oil manufacturer has designed their multi-weight oil (multi-viscosity) around the idea that high temperature 'flattens' the alkanes (chains of carbon) in oil
In other words, until oil hits that 'special temperature' it will not flow suitably through a high performance engine.
Oil is rarely in proper 'condition' at merely 160*F as it typically takes another 20-30*F to get it hot enough to fully 'unravel'

The difference is night and day and can be seen fairly easily on an oil pressure gauge. Once the oil warms past a certain point it 'thins out dramatically' and oil pressure will be seen to drop in the gauge in an obvious way.

Running an engine hard with thick oil (before it fully warms up or just plain thick), or starting one with cold oil (still thick) will reduce oil flow (the speed of oil flow, which means more pressure on the gauge and less oil flow through the engine).

2. Oil temperature below 212*F~ will not be hot enough to drive away water molecules. This is a potential for big issue if the engine is never fully warmed up and should be research further.

 

If a car has questionable cooling then I put a 180 in. If its got good cooling I put a 195 in.
I think never getting over 170 is a problem and your going to run in to sludge issues.

 

you run too cold for a long time you wear big ridges in the top of the bores. but this is daily driving for years with no thermostat.

 

Honestly this should be seen as an opportunity to upgrade install a pair of high performance electric fans.
Allow me to re-phrase this. "I wanted the advantage of being able to cool my engine coolant below 180*F so I added electric fans and dropped the thermostat opening point"
This is the correct way to advance "one level" in terms of cooling and performance because it allows the owner to decide what temperature is needed.
For example:
Highwaycruise best economy will generally be between 200-220*F or hotter, so for example set the fans to come on 200*F+ after 55mph
Idle in traffic with cold oil: Let coolant touch 210-220*F if just idling in traffic and oil temperature is below 180*F to facilitate oil warming and engine ready state
Idle in traffic with hot oil: Maintain 165-175*F Coolant when engine oil temperature reaches threshold 205*-215*F to keep oil and intake pathway parts cool
Racing around at part throttle with A/C on and hot 216*F Engine oil: Maintain the lowest coolant temperature you can and use aux coolers to keep trans temp 165*F and oil temp in 200-215*F ranges, upgrade cooler capacity and heat transfer rate until desired ranges are maintained.

As for the electrical aspects of this seemingly innocuous upgrade,
I recommend using 2x 40-amp relays to drive one large fan, or three 40-amp relays to driver 2 medium fans. Never trust a single 40-amp relay to run a 40-amp fan, especially if they send you a 40-amp relay to use with their own 40-amp fan (joking but not joking)
Ebay sells 60-amp automotive relays which I will test and know for sure shortly and that seems like it would work. But until those relays were offered at low enough price, the only place to get 60-amp relay reliably is a junkyard SAAB and its 1 per huge 10"x4"x3" box.


Electric fans can draw enough current to substantially load an alternator as well. Keep this in mind if using 85-amp or 120-amp alternators that an upgrade to 185-250amps may be required (depends on the total current draw of course)

So in a way this becomes an potential upgrade. $80-$350 on an alternator, $80-$250 on fans. $50 on wire. And then you need a thermostat for the fan, the ideal way to add this is via existing coolant sensor 3/8" NPT or 1/4" NPT port somewhere on the engine or radiator. That way you are not making any extra holes. For example on LS engine there is a coolant temp sensor in one head, and an empty-unused same-exact port on the other head. You would buy the proper thread sensor for that hole, wherever it is and the sensors can be used a number of ways to trigger fan relays. This project also teaches how to use a relay properly if one is unfamiliar. It's actually quite intermediate level because it involves resistance and current diagrams, there is potential for poor grounding, inadequate wire diameter, improper fan shroud technical, inefficient implement potentials often missed because it sounds so simple to just 'install an electric fan'. You can easily overheat and destroy an engine by improperly adding electric fan to an engine. Especially when A/C piggy back system is involved with coolant for a high performance engine.

 

The actual operating temp of the engine is not going to change by putting in a lower temp T-stat. The engine will still warm up to the same temp as before. It will just take a bit longer to get there.

You folks just need a primer on cooling system basics....

 

As I was reading this thread I was thinking the same thing.
WOW, chaning a

 

We've been down this road before and that's not a true statement. An engine does not randomly find it's own operating temperature regardless of the TS rating used which is what you are inferring.

If I want an engine to run at 160*, I use a 160* TS and also have a radiator of sufficient capacity i.e. holds more coolant, to achieve this. Same goes for 180* but I can use a radiator of smaller capacity. And again for 195*. Why is it that different size i.e. capacities, of radiators are used for cars with a/c and smaller rads with no a/c but all using a 180* TS? Radiator capacity and material used for construction of the rad will dictate the engines operating temperature based on the rating of the TS. Heck, if a vette had the room under the hood for a larger rad, the engine could run at 100*. But that is too cool for the ideal oil temp of ~180* for most cars.

 

the thing that comes up is capacity, total volume of cooling system is reflected in the rate of change of temperature at various operating states
imagine unlimited capacity (lakes) you can cool to any temperature and compensate for any temperature (unless your ship is big enough to start heating the lake. Testing nuclear devices?). Which yes if the cylinder wall is 140*F because coolant is 90-98*F and the oil is 220*F there may be some consequence or metal related fatigue. I think for our materials sake, engine coolant should be within 40-50*F of the engine oil (maybe even a bit tighter) so if oil is 250*F your coolant should be 200*F and you need to work on bringing down the oil before you bring down the coolant. But that is just my opinion. It depends on the materials of the engine and intended application.

 

Yup. You are right resdoggie. In television, this would be called a rerun. And you can't argue with young school that just read everything about cooling on Google.
It makes them an expert because of some automotive tech article. But us old school people know better than what a new text book says.

Anyway, getting back to the original question: YES 160* T stat is fine. Its not likely the temp will stay there but its a start. And to the poster that is concerned about sludge: That occurs from not allowing the engine to ever reach normal temps. It is NOT from constant 160-180 temps. Sludge can form when short drives, such as a few blocks to the store or work every day and the engine never burns off condensation.