barnett468

Well as one theorist here has stated, hotter is better so go ahead and give that a shot.

FYI - Kerp your AAA tow card on ya.

Gun Jam

....all sunshine and bunnies till I hit traffic.

barnett468

your aftermarket gauge should be plenty good enough.

what is wrong with your air gap?

why does a moderator have more threads than other members?
ok, sorry...couldn't help myself.
.

barnett468

Please don't talk like that, it worries us.

Gun Jam

The airgap is awesome but the two ports are used...one for the original temp gauge and one for the heater hose. I have no place to install a second temp sender for an improved temp gauge.

I post a lot because I think about stuff and then it gives me questions. Plus you guys would get bored without me.

-Gun

Starfury

I never did figure out a good solution to that problem, Gun Jam. Unlike pressure gauges, you can't just tee a fitting and make it work; the temp bulb needs to be immersed in the coolant stream. In the end, I disabled my factory gauge and stuck with my aftermarket mechanical gauge.

67mustang302

I have 2 gauges actually. The XFI sensor is in the manifold, and the gauge sensor is in the fitting on the thermostat housing. The gauge temp doesn't give an accurate reading until after the car is moving and the thermostat is open, and it's also not as accurate as the XFI (which is crazy accurate).

Also, thermostat ratings are misunderstood. If I remember how they're specced correctly (numbers might be a bit off)....the rated temp is the rated opening temp +/-4* and they're fully open something like 15* past their opening point. So a 195 can have an opening point anywhere from 191-199 and still be considered "within spec," and it will be fully open by 206-214*. Typically under most conditions the temp will stay around the opening temp, since it usually provides enough flow too cool under normal driving conditions. In really hot weather and/or when the engine is under constant high loads, typically the temperature will run higher. But the thermostat is intended to set a minimum operating temperature, and may or may not be accurate. Cheaper quality thermostats are less likely to be within spec, or even close.

A general rule of thumb that some people use, is to run the hottest engine temp you can that doesn't cause adverse effects (detonation, sluggishness, hard starting when warm etc). I just run 195, which is also what most factory vehicles run; and provides a god balance between running warm enough to increase engine life, help in cold weather driving, reduce deposit formation, while not being so hot as to cause damage based on materials used. Highly engineered (and expensive) engines may run even higher. The highest I've seen were the previous n/a Formula 1 engines (specially selected materials, specially designed high pressure cooling systems) that ran in the neighborhood of 270*F (and were also producing over 800hp from 142cid).

Also, when cruising with a performance engine, the cylinder tends to run colder compared to an economy engine. The valve timing and fuel and ignition settings tend to result in a cylinder that's inefficient, doesn't fill well, and makes reduced power (which is why performance engines get worse mileage). It also means the cylinder is running colder. This causes another problem with CA fuels; since their required by CARB to be blended for air quality purposes, they're generally intended for use in CA emission regulated vehicles. Those vehicles have cylinders that run much hotter at cruise than most of the cars we drive.

If you think it's oil from the PCV, there should be signs in the manifold plenum, you'll see an oil film inside there. But keep in mind, the PCV has been for a while and still is used by cars today. So it's intended that a little oil will get through and be burned off.

A little deposit formation isn't the end of the world either, as long as it doesn't keep getting worse. Run premium Chevron, and if you still have deposits you can run a cleaner through it from time to time. You can also consider switching to EFI, since one of the benefits of EFI is much more precise control of fueling...so you can limit the amount of excess fuel delivered at cruise more easily (carbs tend to deliver a good portion of fuel at cruise through the idle circuit, so it's liquid fuel delivered rather crudely).

Also, if you have a good background in chemistry, math and physics, you might want to consider picking up these books:



Lots of good information in there that will answer a lot of questions about engines from a practical standpoint.

Starfury

67mustang302, which housing are you running? The only one I've come across with a sensor fitting is the factory cast-iron piece (which looks terrible next to an aluminum intake).

67mustang302

It's some OEM cast iron replacement I got at NAPA. I'm less concerned about looks, besides...you could always paint it if you wanted to.

Gun Jam

Thanks a bunch for that helpful post!

I had come across the housing with the sensor fitting but was looking for one that was of good quality. That's the way im going to go. Ill run my stock gauge on the housing and the more precise gauge in the crossover.

-Gun