Cooling system issue....

[wwotr]

Originally Posted by RUSHNBOBO

New motors are a completely different animal than the old technology...most of the high degree thermostats have to do with the emissions and new combustion chamber technology. Most all early Gen 1 sbc came from the factory with 180 degree thermostats if 195 would have been more optimal for these engines that's what they would have used. Especially pre 1971 when smog equip was virtually non existent. Horsepower was king and the comparatively low tech motors of the time were built to run best overall at this temp.

A 160 degree temp can sometimes make a little more power, and curb detonation issues in some high compression engines. But the downside can be too cold of a cumbustion chamber temp which will eventually lead to excessive carbon buildup and possibly an incomplete burn. So on the street a 180 in gen 1 sbc is usually considered the best compromise for both power and clean efficient combustion.

I swapped out the 180 to the 160, because of the detonation, but have since installed an in cab MSD ignition dialback which I can on the fly, adjust the initial and overall timing when I change elevation. Where I live at 2000 ft. the setting is perfect, if I drive to 1000 ft. it will begin to ping, "more dense air". Since max power is made right on the edge of ping or no ping I can now just dial it back to the sweet spot a couple degrees at a time.
I will eventually go back to the 180 so I don't worry about carbon buildup problems and possibly "loading up" the plugs at idle.

How would this relate to MY Engine?
Mine is a 350, out of a 94 GMC 1500 Truck.
I've owned it 3 years and run Regular Grade Gas (the 87 Octane stuff),
and my engine has NEVER Pinged/Detonated, in Cold or Hot conditions.
All I know is that when I was up in Northen California at 3000' Elevation, (where I lived), that sucker never seemed to go above 180.
Now if I went down to the Lake on a hot day (1000' Elevatiuon),
it "might" go to 195, but never OVER that.

So now I'm at 500' elevation and it is WAY Hotter,
(than Northern California), so I knew I'd be running Hotter down here.
But this whole post may be a Bllessing in Disguise",
because obviously I needed a Shroud, (never had one),
and the Flex Fan was inadiquate.
So I know adding the Shroud, Clutch Fan and Thermostat,
cant be a bad thing.
Since I don't know what temp Thrermostat is in my engine,
(and I'm already getting a Shroud and new Fan),
I thought I'd replace the Thermostat and Coolant.
This gives me a Base Line, and now that it's MY Truck,
I'll know what Temp Thermostat is in it, along with the piece of mind that I have a Shroud, Clutch Fan and new Coolant.
Seemed like a good idea, after moving to Palm Springs anyway with this heat.

After 6 years on this Forum, and you guys STILL never cease to amaze me with your wealth of Knowledge.
Hell even I was able to help a few "Newbies" here on the list.
Feels Good!