congratulations on making some progress, I am happy to eat crow if it makes it easier for someone else. I would have lost money on that one. Anyhow congrats and enjoy driving it around great looking truck

 

It ain't over yet!.. so you may still be a contender..

Sam

 

Ok, we used the truck in some movie filming last week (details to follow), and we overheated again. .bummer. Blew less than a qt of fluid, (over the overflow bottle contents, 1.5 pints.. thinking of enlarging the overflow too, not many good choices in chrome/polished).

So, yesterday I pulled the shroud, and mounted the fans directly on the radiator.
I had a 14 in fan, so I replaced one of the 12s with that, so now I have a 12 and a 14 mounted. The 14in is mounted near the top, on the rad inlet side, while the 12 is mounted low on the rad output side (this is the reverse of the shroud placement). Except for a small 1 in band down the middle, where the fans don't quite overlap, all the core has fan coverage. (tranny is cooled externally)

this also provides another 1.5 inches of air flow room between the rad and engine.
and opens the rest of the core to flow thru while moving.

I had to pull the grill to get the A/C condenser off to push the fan support pins thru the radiator.. (so much fun).

I am all wired up, and testing fan pull thru the rad seems pretty good, cold.. we'll see tonight how it does running. I'm takin bets on whether this helps or not!..

then I will remount the A/C condenser and test again.. I think I am going to add a spacer between the A/C and rad (have maybe 1/4 in now)..

Sam

 

What a pain. I also had a lot of overflows when I was breaking in. It would fill the overflow and dump all over the pavement. Funny thing is, I found out that withthe volume of th ecooling system I had, the fluid was expanding so much when it got hot, that It would increase in volume by about 3 quarts! True! So, I stopped replacing it. Now when it's hot, the level in the overflow bottle is where it is supposed to be, but when cool, the overflow is empty and the level in the radiator down about 1 1/2 to 2 inches. So I just left it and it stays cool and runs fine - no more overflow.

Good luck Sam, I know this is a frustrating problem!

 

Thanks Julie.. I don't mind finding some equalibrium. if the heat stays down, I'll be ok.

Sam

 

Sam nice to see you're makin some head way with the cooling system.
All performance engines are going to run a little warmer than most.

I cool my 347 with an aluminum double row cross flow rad, with a 16" 2070 cfm electic curved blade fan controlled with a thermostat. I use a "FloKooler", RobertShaw 160* thermostat in the engine. I dont use a shroud, the fan is mounted the center of the rad about an inch away on a couple of fabbed brackets. It keeps it's kool!

Maybe you could have some louvers punched in the shroud to move some air around or have some slots cut? Just a thought and the koolness of the louvers LOL! Good luck Sam.

 

Doah!.. now that I have removed the shroud I thing i have room for that 16in centered fan.. and I have one somewhere in the shop..

Sam

 

So, my status as of tonight..
the twin fans, 160 degree thermostat

with the radiator only, temps hold at 192ish at idle
driving with rad only, temps drop to 165ish. YEH!!

with the A/C condenser installed, temps rise to 210, at idle. ugh..

I then added a spacer to the A/C condenser mount, slightly over 1/4 inch (a oversided nut slid over the bolt)

with the spacer, temps hold at 205ish, at idle
driving with the A/C condenser and spacer, temps drop to 165ish, YEH..

engine bay MUCH cooler now after driving than before. hood much cooler.
I should be able to adjust the fans to turn off at these temps while driving.

now to see if I can find that single 16 before I put the grill back on. I might space the A/C condenser a little more.

Sam

 

Sam, so I'm trying to follow what you've don to fix problem that gave results.
1) Changed jets from 70 to 72.
2) Removed shroud and installed 1 fan 14 in and one 12 inch.
3) Moved condenser out from rad.
What did I leave out. With temps higher at idle does that mean you need more fan. I love the way the shroud you have looks. The engine bays I've seen with electric fans have flapper vents as previously mentioned. I love your truck I wish mine could someday be half as nice as yours. Kurt G.

 

thanks for the nice words..

also moved the tranny to external cooler,
went to 160 degree tstat (this might be bad now that the temps come down driving)
went to mostly water 90/10 vs 50/50 antifreeze mix.

I think I might still need more fan at idle.. I will look to see if I have that 16in fan.
maybe a single 16 is better than the 12 & 14. altho area size says that the two should be better.. (153+113 sq inches vs 201 sq inches). altho I don't know the actual flow rates on these 2 fans I have.

that monster two speed fan from the taurus with integrated shroud would be interesting to test out on this setup.. it worked great on an old mustang 5.0. takes 70 (yes SEVENTY) amps..

 

Sam, just a observation. Looking at page # 1 and look at your radiator vs your ac condenser. Next look at Julies radiator vs ac condenser a little later in the thread. Hers takes about a quarter of the radiator size. Your about 100%. Could you get by with a ac condenser across the bottom and maybe 5-6 inches high. When you start using the ac you are going to add extra heat to the radiator. Her ac condenser also stands off the radiator a couple inches, this may help also. Does you grille block any air flow? Random thoughts, chuck

Restart the thread and keep it going.

 

recommended A/C condenser spacing from the radiator is no more than an inch for stop/go traffic air flow.

as for size, question is how big does it need to be.. Vintage Air says this size is
reasonable. and their universal fit are only an inch or 2 smaller in each direction.

I think it comes down to the rad size overall.. lower air flow than expected.

just talked to the rad shop, and they don't get it either.. did ask me if I could space the A/C condenser a little more (an inch)

Sam

 

Sam,
Glad to hear you are gaining on it.
My AC condenser is about 1" from the rad, but it only covers the bottom 2/3 of the radiator. When I have the AC on and it's 105' outside and driving 70, the temp runs about 15 degrees higher than when the AC is off. I have my 16" fan running all the time when the AC is on. I run about 190 with the AC on. I have a 165 thermostat. The fan is mounted at the top of the radiator. It runs a little hotter going down the road than it does at idle. I think the shroud is restricting the air flow some. Have been thinking about putting in some rubber flapper trap doors, but it isn't bad as is, and I am a little lazy!
Keep after it !

 

thanks for that info too Don.. I found the 16in fans in the shop, one is a Hayden, rated at only 1400fcm, 1100 typcal radiator it says.. and a no name that I bought, rated at 2500 cfm (I think) thinner than the hayden. (3 vs 4.25 inches)..

I think I'm just going to move the a/c condenser a little more first.. cause I'd have to go get a new mount pin kit to mount the 16.

sam

 

When you space the condenser out, are you sealing the edges against air going around the condenser? If not, I'd suspect the improvement is because air is not going thru the condenser any more. Also, is the condenser a fin-and-tube type, serpentine, or ?? Some types are very efficient but have a lot of air pressure drop (restrict air flow).