2 Questions: AvGas and 160* Thermostat

[blackstangt]

First,
I have a 160 degree thermostat, how bad is this for gas mileage and the engine? Can this be beneficial for any reason, including engine wear, considering oil temp?
Would there be any benefit to installing a 180 vs a 195 and vice versa?

Second,
Someone told me that they used AvGas (100LL) in their C5 Corvette. He said that it helped performance, because the sensors/computer adjusted timing and mixture for the AvGas. He also said that this increased acceleration to a noticable degree. I am skeptical and would think that this would damage several components including emissions equipment and oxygen sensors, possibly fouling the plugs. If 87 octane has more BTUs, this would also hurt fuel economy. Are my skepticisms correct?

 

[5.0ina66]

1) The 160* would be worse for engine wear and MPG than the 195*. Plus, you may have to retune the car to get it to go closed-loop above 160*. For the literally 4hp you might gain, it's not worth it on 99% of the cars out there, IMO.

2) Lead kills 02 sensors and cat. converters. I have no idea why the Vette guy thought this was a good idea? There is a reason they make unleaded race fuel and it is called EFI. Plus, 100LL has a chemical package added to make it perform at high altitude, and that isn't the best thing for automobile performance here on the ground.

 

[Mustang5L5]

Poor corvette getting AVGAS run through it

 

[jrichker]

AVGAS works well in older carb cars, and I have used it in them with no problems.

I worked as an aircraft mechanic for 11 years (A&P licensed for 8), and there were times I had a little gas and a long drive home.
I used to tap the AVGAS dump tank used to drain fuel prior to repairing the fuel tanks. By increasing the base ignition timing to take
advantage of the slower rate at which AVGAS burns at, the result is a smooth running car with a lot of low end kick.

However, as stated by my fellow Stangnetters, AVGAS is not suitable for EFI equipped cars with any kind of O2 sensor.

See http://www.aviationfuel.org/autogas/articles/Autogas vs Avgas.pdf and Aviation Fuel Homepage for more information on AVGAS

 

[Cobra912]

oh boy, glad you started this thread. I refueled aircraft for 5 years, from everything from 747's to cessna 172's. I was tempted many times to throw some 100LL in my car too, because that's what 100LL is = Low Lead. But the more and more I read about EFI engines and 100ll the more I realized that it is best suited for running my lawn mower.

 

[blackstangt]

Funny thing is that he was a flight instructor, you would think he would know about that lead stuff.

The problem with the thermostat is that I bought an electric fan and the on/off temps are based on the thermostat temps. I might try a 180 degree thermostat if you guys think it would be significantly better. If it's only worth it to switch to the 195, I would definitely have to modify the fan set up. Is there any way to make it go closed loop at a lower temperature?

 

[stykthyn]

when I worked at the flight strip my friend ran avgas in his acura for a month and it junked up his cats and made his car run hot for some reason

 

[Mustang5L5]

How low?

Problem with running too cold is it leads to long term damage to the engine. Gaining that extra 5HP may not be worth it.

Some guys like to band-aid a cooling issue with a colder t-stat. Doesn't always work.

 

[blackstangt]

well, 180 or 160 degrees...

 

[2000xp8]

Buy a mr gaskets 180.

Some cooling systems can't even handle a 160, in most cases a 160 pretty much just stays open all the time, and the coolant doesn't stay in the radiator long enough to cool off.
A 160 also can suck in the winter, they have been know to produce only luke warm heat.

 

[Mustang5L5]

well, 180 or 160 degrees...

The question should really be 180 or stock 195

 

[apollo12]

because you live in n.y I would run at least a 180*. I run a 160* however I live in fla where it's always hot

 

[blackstangt]

Coincidence: I have been living in FL for about 3 Years. Moving back to NY soon.

Is it possible to modify it to go closed loop though? If not, will it go closed loop with a 180 deg thermostat?

Is there any benefit to using a 195 degree thermostat instead of a 180 degree? I'm not worried about my heater, so that's not an issue.

 

[blackstangt]

If the car gets to about 200 degrees, the E-Fan comes on, shutting off at about 180. The probe is in the radiator, where the coolant is not that temp. I could probably run a 180 deg thermostat NP, but 195 could be a problem.

If the computer goes 'closed loop', will it stay like that until it turns off? What temp does it go 'closed loop'.

 

[Cobra912]

Buy a mr gaskets 180.

Some cooling systems can't even handle a 160, in most cases a 160 pretty much just stays open all the time, and the coolant doesn't stay in the radiator long enough to cool off.
A 160 also can suck in the winter, they have been know to produce only luke warm heat.

I've had 3 Mr. Gasket thermostats fail on me.........won't ever use them again.

 

[striker911]

So 180 or 195 then?

I just got rid of my 95 with a 6 and got a 86 with a 8. The temp only goes up to 150 at the most. You can tell the car is running lean cause it stinks to high hell, & I am thinking the car keeps kicking up to 2k due to the choke trying to warm the car up? It sucks. Having to shut it off and reset the computer cause it wont kick back down.

Anyways so I have a 89 Camaro too and know that the computers need to be tuned every time you fill up the tank but what about the stangs?
I have
Off road H with flowmaters b-4 the axle.
Some hi-po heads (not sure what kind) with some roller rockers,
Smog delete pulley,
A pretty loopy cam (not sure).
t-5
K&N filter (stock box)
Electric pro-form fan ect.

Can the stangs computer take all that with no tuning? Im not even sure that heating it up to 200 degrees will lean it out much? Its pretty bad. People roll windows up. In city driving I smell it with the windows up. Should I get an adjustable fuel pressure reg to lean it out? Im getting like 12 mpg mixed driving.

Think it has bigger injectors too. The car was mine 6 years ago and I gave it to my dad. After he put all kinds of work into it he got tired of it and gave it back???? LMAO he wants a cutlass. Sorry Furd dudes. Point being Im pretty sure I can find out whats been put on the car if needed? Thanks in advance.

 

[Maryland Stang]

the more I realized that it is best suited for running my lawn mower.

Not for long. Kohler and Kawasaki make most of the engines used in commerical mowers. Both companies have been using EFI for a long time now in selected engines. Both companies are getting ready to switch their entire lineups to EFI. I have a 2003 60" Dixie Chopper with a Kohler 28 EFI. It has the TPS, O² sensor, 2 injectors, T/B, the whole nine yards. Kohler's system is made by Bosch. Kawasaki makes their own system.

Robin-Subaru is currently the only manufacturer of a single cylinder EFI utility engine. Subaru Robin These little engines have almost the entire EFI system built right into the throttle body. It's also a low pressure system.

These ain't your daddy's old 3.5 HP Briggs engines.

 

[HISSIN50]

Striker, pull codes.

For the rest, the stat rating doesn't matter. All that matters is what temp an individual car runs at. It's that simple.

Going into closed loop is a function of time (for the O2's to light off. This happens in 30-120 seconds after starting the enginee), not engine temperature.

 

[Maryland Stang]

Here's that throttle body.