V8 temp in 105 degree weather (1 Viewer)

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Oct 16, 2015
I ran my cruiser for the first time in 105 degree weather yesterday, during stop and go it was running around 195. When I idled in parking lot for 10 minutes it went up to 220. The 220 seemed to be the max temp, never went above this. Started driving again and it went right back down to 195. I have a SB 350 w/aluminum radiator and shroud on mechanical fan with a 180 thermostat. Is this about normal? It was damn hot yesterday, I rarely drive in these temps but I wanted to see how the radiator would cool the engine. Not sure what more I could do at this point other than change out to a different mechanical fan. On a 90-95 degree day it never goes over 195 even when idling for prolonged periods of time.

Should I just leave it be or think about upgrading the cooling system?
I can't say that I've run in 105 degree temps, but my 96 5.7l cycles between 195 and 204. It gets up to 204 when I'm shoveling the coal to it up mountain passes in 4th gear. If I shift to 5th gear, it drops down into the 190s. I do have a later-model nylon fan from a Yukon or similar and it has more blades than the stock fan.
I live in Qld, Au where it's generally hot a f**k. In fact I think this may be the origins of hell itself. When I shut down my V8 it jumps up to 220 and drops slowly as it cools. If I fire it back up it drops straight back down to the 190's. I reckon you'll be fine IMO.
What's your anti-freeze ratio? 50/50 is typical, but in hotter weather you'll get better cooling with more water, say 25/75. If you garage your rig in the winter and you're in the central valley, that ratio will work about 95% of the time.
Stop and go traffic can do this. My carbed 350 extracted from a '78 GMC Jimmy occasionally hits 220 ( according to my old cheapo gauge,) here in the intense SOFLO heat coupled with our long freaking red lights. Mine went to the shop last week for timing and carb adjustment, I put on a new Quadrajet and engine had not been timed for years. I think it was a mistake as my Cruiser seems to run hotter now and mechanic said the timing was off. I told him to put it back where it was. retarded timing can increase temp. Mechanic tested the temp and said that my old add on cheapo gauge was inaccurate and off by 10 to 15 degrees on the hot side; Could be. sggoat and I are putting in a new temp sender with sbc adapter and getting my stock gauge working, and also replacing cheapo temp gauge with a quality electric unit. My engine has never boiled over and this is the second mechanic that said my hang on gauge is not accurate. For fun I'm gonna hit the junkyards to see if I can find an old Volvo 240 electric fan/shroud and relay and put it on.
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What is the best mechanical fan to use for pulling air? I need to take a look and see what type of fan is on the vehicle. The radiator mix is currently 50/50, I just installed new hoses and flushed it out this past spring filling back up with 50/50 premix. The radiator is a Man A Fre aluminum. The gauge is autometer mechanical so I am assuming temp reading is accurate.
I think the fan I have is from a Yukon or similar large truck with A/C. I believe the stock fan for my engine was a 7-blade. This thing moves air.

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Drove mine today in 100 degree temps (stop and go freeway), 180 moving and 195 stopped. Sounds like you need to investigate fan or shroud, mine is the stock mechanical with a nice custom shroud.

[QUOTE="Lil'John, post: 10488551,
For Captn Conch, you might look at 1998 Dodge Intrepid electric fans. They have a flat mounting surface and are loved by the V8 converted S10 guys :)[/QUOTE]

I'm running my stock original 4 blade 40 fan and shroud (hacked up and not very functional,) with a Man A Fre 4 Core I bought long ago and have got along for 25+ years with the combo. But there is certainly room for improvement. I gotta try a tight fitting properly shrouded electric fan. There was a Mud and Pirate 4x4 post about the 90's Volvo electric fan/shroud/relay that looked like a great option. I'll check out the Intrepid fan.
That looks like what's happening..I used to have a '76 55 that I sure miss but I don't recollect if they used the same size radiator as the early 40??
It's just a stock Chevy/GMC fan and clutch from a larger late model truck/van (Suburban, Yukon, Savana, Sierra, etc) that directly replaced the original fan on my engine. I don't recall whether I got it at a junk yard or from Ebay, but it wasn't expensive and it moves a lot more air than the original fan. I built a fiberglass shroud to mate it to the 19x22 (IIRC) aluminum rad. The fan is 19-20 inches in diameter.

96 97 98 99 CHEVY GMC 1500 2500 3500 SUBURBAN TAHOE 5.7 * FAN CLUTCH WITH BLADE

11 blade chevy gmc cooling fan | eBay

Shroud 56.jpg

Finished-Installed Shroud1.jpg

Not to Hijack but I'd like to see/hear more about that fan:
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