Why not just remove thermostat?

[KILLSHOTS]

I've seen colder thermostats for the LT5 discussed and they're apparently extremely desirable but tough - if not impossible - to find. I live in Phoenix and my car is just a weekend toy. We all know that a cooler engine produces more power. We also know that thermostats are basically only designed for 2 things: allow the engine to run "efficiently" (read: please the EPA) and to produce heat for the cockpit. I don't care about either. So can anybody think of a COMPELLING reason for me to retain my thermostat? Less heat soak, less wear on the engine, more power. Opinions?

Thanks!

[mike100]

The car runs rich until it warms up and it will wash down your cylinders in short order if you take it on short drives with no thermostat.

I once thought I'd be smart and ran a 160 'stat in Flagstaff on a carb'd muscle car. It got to 15 deg that night. I never could get my windows defrosted. You should always try to get your water and oil temp up as soon as possible, the engine will last much longer.

[Vetman]

Thermostats when open let the correct amount of water flow to optimize cooling. I understand removal will allow the water to flow too rapidly through the radiator before it is cooled. Guess there may be other reasons too with water flow too fast.

[tccrab]

I've got to guess that emissions control are a big reason why the engineers design engines to run within certain temperature ranges.

I'm also guessing that the thermostat provides some restriction to water flow as well. The volume and pressure of coolant the water pump pushes when the engine is at 7500rpms is vastly different than at idle.

'Crabs

[efnfast]

I asked Marc H about a 160 thermostat. He said it may gain as much as 10 hp, but was concerned that the oil and gas are engineered to run at higher temps. Not that I mean to put words in his mouth, but that is what I heard. -Steve

[XfireZ51]

ECM doesn't go Closed Loop/Learn mode till 81C or 178F. So you pretty much lose any fuel trim from the O2 sensors. The motor is really designed to run better at a warmer temp than 160F.

[GOLDCYLON]

Chris I run a 160 Degree T-stat on my Daily runner. For Phoenix it works well as the days are now in the Century range. Even in the brutal winter season when it gets into the 30s I have zero issues with defrost and heat as well as we all know very well the car heats up rapidly. Keep in mind my car is highly modified engine wise and I run a larger Dewitts radiator and SPAL fans. So your mileage may vary. I do not recommed running without a T-stat GC

[XfireZ51]

GC,

What temp does your motor run at?

[Bob Eyres]

Remember, 160deg. is where a 160deg thermostat is designed to open, and not that the thermostat keeps the engine at that temp.

The LT5 is a lot stronger with cool intake temp, but that's another issue.

I have run a 160deg. thermostat for 17 yrs. in my ZR-1 with no ill effects. It has helped keep temps down in the hot Florida environment.

I would think that it would be ill advised to remove the thermostat entirely.

[Paul Workman]

Well, for starters:

1. Engines are expected to become hot.
2. Parts are expected to expand.
3. Parts work together best within certain tolerances.
4. Heat is controlled to keep parts tolerances in the range to assure longevity.
5. Lubricants are designed to specification that they meet certain characteristics over a range of certain temperatures.
6. Fuel (gasoline) must be completely vaporized to mix with oxygen before it will burn. (liquid gasoline droplets will only burn at the surface where oxygen is present)
7. Operating the LT5 (or any) motor at WOT below a certain minimum temp can result in damage (refer to #s 2, 3 & 5)
8. Operating (any) motor where gasoline is not being vaporized completely results in carbon buildup in combustion chambers and on valves, washing the cylinder walls of needed oil, and reducing the viscosity of the oil resulting in accelerated wear of cylinder walls, bearings, and rings.
   
9. And, last, but every bit as important, in the case of the LT5, certain steps are taken in the thermostat housing (with the thermostat in place) to control coolant over-pressurization resulting from high rpm operation.

These LT5s are a magnificent engineering achievement. They are kinda rare, parts are expensive, and provide a rare experience not felt in any other Corvettes before or since. And, when operating within their "window" they are nearly "bullet proof". If you operate this or any motor outside the design window, as some always will, you're "off the chart", and serendipity becomes your tutor. (But, NOT on my dime!)