Time for a Radiator Upgrade...?

[AuroraGirl]

Mine is also the 8600GVW and federal emissions. No, canister on mine and I also have the vent tube and cap similar to the differential caps. In our situation it doesn't really hurt anything to have the vented cap. It's just extra venting. The problem comes when you run a non-vented cap on a canister system. Then you end up with a vacuum in the tank and fuel starvation when the pump can't overcome it.

ohh okay good to know. I dont know anythign about what the truck looked like under the hood just that it didnt have cats, single exhaust, 350 with low hp, a 4 speed manual, and a 205 t case with slip yoke, 1 piece driveshaft. heavy duty springs front and back. and a lot was cobbled together over the years, so its a puzzle sometimes. I do know where my original engine and qjet are, the engine is chilling out laying vertically in the back of the shed with everything off it and the qjet is hanging next to bird nest on top shelf next to a set of plug wires.

 

[Grit dog]

Or to sum up 4 pages, a new or freshly tanked radiator will almost certainly keep the truck running much cooler, regardless of the presence of a thermostat or the particular temp of the thermostat.

 

[AuroraGirl]

and this is, i think, the original tailgate lol

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its now yellow and the rip in the center is wider

 

[AuroraGirl]

Or to sum up 4 pages, a new or freshly tanked radiator will almost certainly keep the truck running much cooler, regardless of the presence of a thermostat or the particular temp of the thermostat.

and proper fan., clutch, shroud. to direct air through the radiator when not moving.

 

[Raider L]

@7900_Blazer,

Your fan is too far in the shroud. It should only be about an inch, (1") sticking out on the engine side. Too far in and the air ends up going around the fan. The blades need to be close to the edges of the opening of the hole in the shroud so nothing but the fan is drawing air through the shroud.

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Like this. Mine may be off a bit, but 2/3rds. of the fan need to be inside the shroud. I have the factory fan on my engine and the blades are wide. With the engine running in Park I can stand in front of my grill and and feel suction against my pants.

 

[Raider L]

@7900_Blazer,

Yeah, what's up with the pulley on your alternator? The V belt should be even with the top of the pulley, not sunk down in the pulley like that. Do what @Bextreme is saying, have a shop redo it, like @AuroraGirl is saying about the shroud, and getting a clutch. Since I don't think you're to concerned about horse power loss, find a factory fan and don't use the flex fan. Now, GM did put flex fans on some engines, I don't know when or on what they were on, but even with my high performance engine I wasn't going to sacrifice cooling for a fraction of a horse power loss and ran a steel heavy fan!

We're all saying the same thing, but basically we are saying keep the radiator you've got and clean it up. It looks like a two-core? But from what I can see it appears the cores are wide. That may be good. It looks like there is a lot of space between the cores which tells me those might be, can't tell, 1" cores. That is good for what you'll need it for. I for one prefer a 180 degree thermostat. That's what the factory installed in the 350 and that's what I've stayed with all this decades and I've never had a problem even when I was towing my mother-in-laws old heavy Skitter boat up and down all those hills in East Texas in the Summer, with a 50 horse Johnson on it, and loaded with everything including all the crap we used to haul to the lake!

 

[Raider L]

When I had my engine rebuilt a friend of mine who was in charge of the engine rebuild based on my spec's asked if I would be willing to try a "restricter disc" in place of a thermostat. NASCAR and some racers use them mostly because they run at one speed all the time and don't have any stop and go driving. Moroso makes a set of them in different diameter hole in the disc. We tried the next to largest size just to see.
What they do is they don't allow any water to stay in the radiator, they just allow a certain amount of flow depending on the hole size, largest the most water, the smallest the least of flow back into the engine. It was a interesting experiment but useless on the street. I took the one we had put in there out and installed a thermostat because the engine couldn't get cool, it just stayed hot all the time.
That's the same thing as running a to cold thermostat, like the 165's. For one thing they open to early and open up all the way to soon, and stay open not allowing water to stay in the radiator to cool down. I knew several guys who had high performance engines in their cars and claimed to not ever have over heating problems. I didn't understand how they couldn't keep from having over heating problems unless he just never drove the car long enough in hot atmospheric conditions to really heat the engine up. Also, they must have had a very clean radiator and a good fan and proper shroud set up.
@7900_Blazer, your engine running 210 to 220? would be like the thermostat being open all the time and never allowing water to stay in the radiator long enough to cool down before it went back into the engine. And, as we see the condition of the poor radiator what cooling that was taking place was very low and by the time the water got back into the engine it was still hot.

I know some may be thinking about those restricter disc's in the NASCAR cars, how do they keep from over heating? They're doing 180 mph and there's so much air going through the radiator no amount of heat can stay in the water!

 

[AuroraGirl]

When I had my engine rebuilt a friend of mine who was in charge of the engine rebuild based on my spec's asked if I would be willing to try a "restricter disc" in place of a thermostat. NASCAR and some racers use them mostly because they run at one speed all the time and don't have any stop and go driving. Moroso makes a set of them in different diameter hole in the disc. We tried the next to largest size just to see.
What they do is they don't allow any water to stay in the radiator, they just allow a certain amount of flow depending on the hole size, largest the most water, the smallest the least of flow back into the engine. It was a interesting experiment but useless on the street. I took the one we had put in there out and installed a thermostat because the engine couldn't get cool, it just stayed hot all the time.
That's the same thing as running a to cold thermostat, like the 165's. For one thing they open to early and open up all the way to soon, and stay open not allowing water to stay in the radiator to cool down. I knew several guys who had high performance engines in their cars and claimed to not ever have over heating problems. I didn't understand how they couldn't keep from having over heating problems unless he just never drove the car long enough in hot atmospheric conditions to really heat the engine up. Also, they must have had a very clean radiator and a good fan and proper shroud set up.
@7900_Blazer, your engine running 210 to 220? would be like the thermostat being open all the time and never allowing water to stay in the radiator long enough to cool down before it went back into the engine. And, as we see the condition of the poor radiator what cooling that was taking place was very low and by the time the water got back into the engine it was still hot.

I know some may be thinking about those restricter disc's in the NASCAR cars, how do they keep from over heating? They're doing 180 mph and there's so much air going through the radiator no amount of heat can stay in the water!

i imagine those systems are also under higher pressure too, so higher boiling point, or they utilize some different technology that i wouldnt know of lol that helps too. considering those engines dont live long lives im sure they have a special coolant that probably not good for an engine but the amount of time it spends in theirs maybe they negate that

 

[Bextreme04]

i imagine those systems are also under higher pressure too, so higher boiling point, or they utilize some different technology that i wouldnt know of lol that helps too. considering those engines dont live long lives im sure they have a special coolant that probably not good for an engine but the amount of time it spends in theirs maybe they negate that

You aren't allowed to run anti-freeze on any race track that I've ever seen. You are usually limited to water only with some approved additives like "water wetter" or "Engine Ice" that promote heat transfer and add some corrosion inhibiting properties without using ethylene glycol. Ethylene Glycol can contaminate a track and make the surface very slippery if there is a leak, which is why it is banned at many tracks.

 

[Grit dog]

Edit, nvm

 

[AuroraGirl]

You aren't allowed to run anti-freeze on any race track that I've ever seen. You are usually limited to water only with some approved additives like "water wetter" or "Engine Ice" that promote heat transfer and add some corrosion inhibiting properties without using ethylene glycol. Ethylene Glycol can contaminate a track and make the surface very slippery if there is a leak, which is why it is banned at many tracks.

thats why i said special, i didnt think any nascar let alone race car would have regular coolants for 1) depending on engine there may just be a lot of combustion gasses that get into cooling system, so that wouldnt mesh well with additives i dont think
2) There is probably something better than that for short term, water wetter sounds about right lol. but obviously has its place there and not in most vehicles

 

[Bextreme04]

thats why i said special, i didnt think any nascar let alone race car would have regular coolants for 1) depending on engine there may just be a lot of combustion gasses that get into cooling system, so that wouldnt mesh well with additives i dont think
2) There is probably something better than that for short term, water wetter sounds about right lol. but obviously has its place there and not in most vehicles

The reality is that they are less "special" because they only really need to operate in one steady state type of situation. They don't need fans, or shrouds, or high/low temperature stability because they are running full bore and as fast as they can all the time. They are never needing to run in below freezing, or stop and go traffic at 100+ degrees with the AC on full blast. So they have a fixed restriction in the thermostat spot to provide maximum heat transfer through the radiator(you can calculate what that needs to be fairly easily) and they try to keep the engine as cold as possible to make maximum power. I would expect a lot of them to not even use any additive, just straight distilled water.

 

[AuroraGirl]

The reality is that they are less "special" because they only really need to operate in one steady state type of situation. They don't need fans, or shrouds, or high/low temperature stability because they are running full bore and as fast as they can all the time. They are never needing to run in below freezing, or stop and go traffic at 100+ degrees with the AC on full blast. So they have a fixed restriction in the thermostat spot to provide maximum heat transfer through the radiator(you can calculate what that needs to be fairly easily) and they try to keep the engine as cold as possible to make maximum power. I would expect a lot of them to not even use any additive, just straight distilled water.

Oh cool lol. I know my uncle's Midwest modified 350 he is very religious on the system because he paid a lot for the custom radiator on it. Pretty beefy aluminum one
But of course over 100 octane race gas, pretty close to right off the damn exhaust is really short headers that dump a few feet back, welded advance weights, no vac advance, direct couple for when racing only a trans to allow reverse, no charging system , high volume mech pump, a brand new Holley tuned in and some serious compression numbers that makes it need a toggle and a button for starting(high compression and advance doesn't let it spin fast enough without prob damaging starter and flywheel lol) and the cooling system peculiarity all makes for one unique situation we definitely can't compare to our trucks lol.
He uses 20w50 too and I think the oil pressure is bumped up

 

[MikeB]

.60 over 350. running this combo for 21/2 years now. I didn't put the 160 in for the trans specifically. one of the best running small blocks i've ever had. Tell me why you think this is too cold even though i have no intention of changing it.

Hi Peats. The main thing is keeping the oil temp at 212 or higher to burn off moisture and combustion blow-by contaminants in the oil. Depending on the engine, that typically means maintaining the coolant temp at 195-200 or higher, and getting to that temp as quickly as possible. If you google "ideal coolant temperature" you'll get all kinds of hits on why 160 is no longer needed with modern oils and coolants. Apparently 160-180 t-stats were sort of a "crutch" back in the days to protect the engine from lower quality oil and coolants available back then. And because the contaminates and moisture were not burned off at those low temperatures, oil change intervals were much shorter to get the contaminated oil out of the engine.

 

[AuroraGirl]

Hi Peats. The main thing is keeping the oil temp at 212 or higher to burn off moisture and combustion blow-by contaminants in the oil. Depending on the engine, that typically means maintaining the coolant temp at 195-200 or higher, and getting to that temp as quickly as possible. If you google "ideal coolant temperature" you'll get all kinds of hits on why 160 is no longer needed with modern oils and coolants. Apparently 160-180 t-stats were sort of a "crutch" back in the days to protect the engine from lower quality oil and coolants available back then. And because the contaminates and moisture were not burned off at those low temperatures, oil change intervals were much shorter to get the contaminated oil out of the engine.

isnt a big block usually an exception, to my understanding they get hot in pockets that the gauge isnt at, but running a hotter t stat could mean too hot in those hot spots?