Restoring Rusty

[Gregski]

pressure tested the cooling system next, and heard a hissing sound by the inlet hose (top driver side) there appears to be a tiny crack/leak there and another tiny one somewhere towards the passenger side on the bottom, not show stoppers, but this do place the radiator on the Parts Replacement List

[Gregski]

Gentlemen I'll be brief:

NO THERMOSTAT

NO PROBLEM


DISCLAIMER: We are not going to run without one, this is just a great clue.

[blazer2007]

did you try a high flow thermostat yet?

[Gregski]

Originally Posted by blazer2007

did you try a high flow thermostat yet?

I have not, not yet, thank you for the suggestion, to be honest whichoo I have not heard of a high flowing unit, is that what they mean by a 180*F vs the stock 195*F? or is it something totally else

[blazer2007]

It has a larger area for the water to flow through so is not so constricted,they are a little pricey $15 or so

[Wgesnerjr]

After seeing that, I for one, would condemn the Duralast Thermostat. If the engine is that cool without a thermostat, I would have to think the AutoZombie part is not working correctly. It may be opening enough to not overheat, but not opening enough to get the temp where it needs to be.

I would try a better part. Maybe a Stant? Maybe a 160 or 185 degree just for some wiggle room.

[Jake Wade]

Get a 180º AC-Delco thermostat.

[rich weyand]

Stick with the stock 195, but get a quality unit. You want the engine to come up to normal operating temp. This helps a bunch of things, among them lubrication.

[Gregski]

first I plan to test mine

then I intend to step up to a name brand one, and test that one before even installing it

next I think we may need to run a 180* or even a 160* F with the Vortec heads, only testing will tell

and finally theres that high flowing thermostat option, who knew this little guy had so much impact, (what a control freak) ha ha

as an FYI I will save drilling holes in the Thermostat as the last resort, lol

[SkinnyG]

What kind of head gaskets did you use?

[Gregski]

Originally Posted by SkinnyG

What kind of head gaskets did you use?

these are the cylinder head gaskets I am using GM Chevrolet Performance part number 10105117 as per the GM turn key engine build specifications

[hatzie]

High flow thermostats would be the units like the 195°F Stant 45359 SuperStat

To regulate coolant at roughly 195°F the thermostat needs to be fully open at 200°F and closed somewhere around 180°F.
You don't want to run 160°F thermostats in a daily driver. Fuel mileage and engine longevity will suffer. Normal coolant temp should run between 200°F and 230°F. This will keep the engine oil above the boiling point of water to boil off any condensation and unburnt fuel to be exhausted out through the PCV system... These temps will still keep the oil below the temps where it'll start to burn and coke up the engine and the combustion chamber will run at a fairly efficient temp.

The 1970's OEM temp gauge is a poorly calibrated guide at best. Only slightly better than a warning lamp because it gives you a heads up before you get to OMG IT'S TOO HOT. Most aftermarket gauges are little better.
If you really want to know what temps the engine is running you'll need a good quality infrared thermometer. The $30 Lowes, Home Despot, and Horrible Fright units don't qualify. You're going to spend over $70 for a decent one. My old Fluke cost over $130
There really is no reason to trust a 42 year old nail head sender. If it's a new unit it's likely either badly matched to your gauge or, if it's a Letric Limited unit, defective.

[rich weyand]

Originally Posted by hatzie

High flow thermostats would be the units like the 195°F Stant 45359 SuperStat

To regulate coolant at roughly 195°F the thermostat needs to be fully open at 200°F and closed somewhere around 180°F.
You don't want to run 160°F thermostats in a daily driver. Fuel mileage and engine longevity will suffer. Normal coolant temp should run between 200°F and 230°F. This will keep the engine oil above the boiling point of water to boil off any condensation and unburnt fuel to be exhausted out through the PCV system... These temps will still keep the oil below the temps where it'll start to burn and coke up the engine and the combustion chamber will run at a fairly efficient temp.

The 1970's OEM temp gauge is a poorly calibrated guide at best. Only slightly better than a warning lamp because it gives you a heads up before you get to OMG IT'S TOO HOT. Most aftermarket gauges are little better.
If you really want to know what temps the engine is running you'll need a good quality infrared thermometer. The $30 Lowes, Home Despot, and Horrible Fright units don't qualify. You're going to spend over $70 for a decent one. My old Fluke cost over $130
There really is no reason to trust a 42 year old nail head sender. If it's a new unit it's likely either badly matched to your gauge or, if it's a Letric Limited unit, defective.

Agreed on keeping the 195 for the reasons stated. Also, oil viscosity varies with temperature, and you want to get the oil up to operating temperatures so it's fluid enough to provide good lubrication by getting into all the nooks and crannies.

The Harbor Freight infrared thermometer unit I have has actually been pretty accurate when checked against more substantial units. May vary unit to unit, but mine at least seems OK.

Agreed also on the sender units with one exception. American Autowire makes a 1513321 correct substitute, with the resistance curve matched to the 1978 and earlier gauges. Any other substitute will not match the gauge.

[rusty76]

We used to use an infrared unit from HF while checking tire and rotor temps on the race car before switching to probes. The HF worked fine and was well calibrated against the probe long acre unit we used.

[hatzie]

Originally Posted by rusty76

We used to use an infrared unit from HF while checking tire and rotor temps on the race car before switching to probes. The HF worked fine and was well calibrated against the probe long acre unit we used.

I've had two. They were both pretty dodgy. Must be luck of the draw. Gloom despair and agony on me...
The Fluke was pricy but It's been great since day one.

[Gregski]

so tested the 1999 Suburban Valucraft thermostat rated for 195* F

it also don't open until 205*F

[Gregski]

more importantly gauges showed up, we got a brand new Summit brand water temp gauge in green and a matching oil pressure Summit gauge also in green (we'll deal with that one later)

naturally it came with a 1/2" NPT adapter (would it kill em to send the 3/8ths?)

so it will be mounted in the water outlet initially than transplanted to the intake manifold driver side

[Gregski]

What's in the big white box?

patience ODBI

[Gregski]

alright so equipped with the brand new digital water temp gauge and sending unit it was time to go back to square one and install the 195* F thermostat back in to see how hot actually the truck runs, and so we did and guess what the guage never read above 199* F and we drove it hard for 30 minutes like we do in all our tests

by the way I love this new gauge it says a number and the word TEMP what more do you need, it is absolutely brilliant

but wait does it show the display in 7 different poser colors, absolutely NOT, and we love it that much more for it

the gauge took about 10 minutes to install and 9 of those minutes were spent looking for long enough cables to install it in the cabin, lol

black to truck ground

red to switched 12 volt power

blue to sending unit

purple (is a mickey mouse wire for dimming the gauges) no thanks for now

so while driving ie moving we were reading 194* F and while stopped at a red light we were reading 197* F

[rich weyand]

Originally Posted by Gregski

alright so equipped with the brand new digital water temp gauge and sending unit it was time to go back to square one and install the 195* F thermostat back in to see how hot actually the truck runs, and so we did and guess what the guage never read above 199* F and we drove it hard for 30 minutes like we do in all our tests
...
so while driving ie moving we were reading 194* F and while stopped at a red light we were reading 197* F

Went back and re-read this post. That's perfect right there.

[Eraser475]

I love your writing style and build. Is that a 6" tall air filter?

[Gregski]

Originally Posted by Eraser475

I love your writing style and build. Is that a 6" tall air filter?

thank you so much, I appreciate the feedback

6" air filter, are you insane bro? it's a modest 5" ha ha

have we tried to shut the hood yet? um no! more on why the hood is still off later

[Eraser475]

Haha, I was just curious since I made an aircleaner that accepts 6" tall air filters for my 6.2 Diesel, but then I couldnt find a 6" tall filter other than K&N. Since I dont like sucking dirt into my engine and think K&N filters are next to worthless, I ended up taking two 3" Wix paper filters and gluing them together for now.

I really enjoy the work you've done on the A833 transmission as well, since i was lucky enough to pick up an '82 K-10 6.2 Diesel that had one in it for $100. I'll be tinkeringnwith that over summer

[Gregski]

judging from those numbers above the truck is fine, we are not running hot at all, I would say 190* to 220* F is a perfect range for an SBC, however since we know the Vortec heads are pronned to cracking (ask me how I know, LOL) we are gonna give a 180* F thermostat a try tomorrow

we bench tested it tonight, and it seems the most responsive out of all of them, opens at around 190* F

[Gregski]

HOW YOU LIKE ME NOW?

... just added 3 inches to my street credit!!!