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!

[GASoline71]

Roger... Is your 350 still equipped witht the stock TBI from 1994? If it is... you'll need a 195 degree t-stat.

Gary

[RUSHNBOBO]

Originally Posted by wwotr

How would this relate to MY Engine?
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.

I would have to assume that you have a 180 thermostat since it stayed at that temp before,(make sure this is right one for your engine) . Now that your in a hotter environment something may be inadequate..is 195 bad? not really ...but if you have a 180 degree thermostat you can keep the temps there.

Your on the right track w/ the fan and shroud setup, at low speed or stopped these are the number one things to check because you probably have airflow issues. Chuck the flex fan...I've never been a big "FAN" of flex fans. I've seen tests between factory type thermo clutch setups vs. flex fans and the factory setup beats it in horsepower used and cooling. They are hard to beat unless you want to drop hundreds into a high end electric setup. The cheap electric one's just won't pull air like the aggresive pitch thermo factory setup.

--Also ... absolutely chuck the rad cap and thermostat then flush and fill. Do these whether you know it needs it or not ....cheap and easy stuff !!!
--Make sure your timing is not excessively retarded...this will cause overheating too. Try to run as much timing advance as you can without excessive starter load and or pinging. This will make more horsepower, quicker throttle response, fuel mileage and run cooler....nuthin but good.

[landsurvey1]

Originally Posted by wwotr

Landsurvey...
Is that driving around town in stop-n-Go traffic?
That's my issue, as I rarely do any Freeway Driving.

Yeah, it seems to run about the same down the freeway or in town. You will be really happy with the shroud and new clutch fan, I have the same set up on mine. I bet it will make a world of difference. You might want to consider using Water Wetter or some similar brand like Royal Purple when you change the fluid as others have mentioned. As hot as it gets here, I run a mixture of 30% antifreeze, 1 bottle of Water Wetter and the rest water.

[RUSHNBOBO]

Originally Posted by landsurvey1

Yeah, it seems to run about the same down the freeway or in town. You will be really happy with the shroud and new clutch fan, I have the same set up on mine. I bet it will make a world of difference. You might want to consider using Water Wetter or some similar brand like Royal Purple when you change the fluid as others have mentioned. As hot as it gets here, I run a mixture of 30% antifreeze, 1 bottle of Water Wetter and the rest water.

That's a good combo, for cooling... I've run mine between 15 and 20 percent antifreeze for the last 5 years ...no corrosion, cools great. Wouldn't recommend this low in winter or colder climates, might get a big surprise when the temps get in the 20's. But lower antifreeze ratios=better cooling.

The antifreeze companies wont tell you this (not in their best interest) they always say 50/50 ...this is not optimum for cooling but is for anti-freezing properties . It is a well know fact that straight water outcools any antifreeze mixture. But this can cause other obvious problems.

[wwotr]

Originally Posted by landsurvey1

Yeah, it seems to run about the same down the freeway or in town. You will be really happy with the shroud and new clutch fan, I have the same set up on mine. I bet it will make a world of difference. You might want to consider using Water Wetter or some similar brand like Royal Purple when you change the fluid as others have mentioned. As hot as it gets here, I run a mixture of 30% antifreeze, 1 bottle of Water Wetter and the rest water.

I was under the impression, (from some Members here),
that products like "Water Wetter", were not compatible with Coolant.
I havent researched it, but rather just going on what was mentioned here.

[RUSHNBOBO]

Originally Posted by wwotr

I was under the impression, (from some Members here),
that products like "Water Wetter", were not compatible with Coolant.
I havent researched it, but rather just going on what was mentioned here.

copied from Red Line's own site:

"Compatible with new or used antifreeze (including DEX-COOLTM and long-life versions) to improve the heat transfer of ethylene and propylene glycol systems"

http://www.redlineoil.com/product.aspx?pid=74&pcid=10

[landsurvey1]

Originally Posted by wwotr

I was under the impression, (from some Members here),
that products like "Water Wetter", were not compatible with Coolant.
I havent researched it, but rather just going on what was mentioned here.

This is my personal opinion, but I think the claim that any of these additives can make a daily driver engine run as much as 20 degrees cooler is a bunch of bs. If you are looking for 20 degrees, you have a much bigger problem than an radiator additive. With that said, I do believe that it does help with air pockets and the cooling of the heads. With all the research I did, I was expecting around 5 to 7 degrees cooler, and thats about what it wound up being as far as I can tell with the combo I mentioned.

Redline: Water Wetter
Rust and corrosion protection allows for use of straight water in racing or reduced antifreeze levels in warm climates

[wwotr]

Originally Posted by GASoline71

Roger... Is your 350 still equipped witht the stock TBI from 1994? If it is... you'll need a 195 degree t-stat.

Gary

Gary,
I believe my Truck does NOT have a TBI...(Traumatic Brain Injury).

That being said...what "TBI" are YOU refering to?
I'm not that "Up" on engines after 86 or so.

[leddzepp]

TBI = Throttle Body Injection

[wwotr]

Originally Posted by leddzepp

TBI = Throttle Body Injection

Uhm.....OK I'm Carburated with and Edelbrock Carb.

[GASoline71]

Then go with a 180 degree t-stat for a carbed 1st gen small block.

At least that's what i use with no probs.

Traumatic Brain Injury!! That was good mang!

Gary

[RUSHNBOBO]

Originally Posted by GASoline71

Then go with a 180 degree t-stat for a carbed 1st gen small block.

At least that's what i use with no probs.

Traumatic Brain Injury!! That was good mang!

Gary

yup, 180 will give you good heater output and the best all around performance in gen 1 (early......pre TBI) sbc

[Andy4639]

Just another thought here to.

I have ran into this before. The stock gauge in our model trucks may not give a good reading if the temp senor is for that motor and not our year motors. You may want to check that. When I put my TPI motor in the truck it read high all the time. I had to get the sendor out of the old block and install it. It reads just like it should have then.
This may have been covered.