70orangeswinger
Well-Known Member
Haven't posted in a while but I was told that I should install a solid or direct fan, as opposed to a clutch fan for my overheating 340 Can anyone recommend one?
Solid fan
- Thread starter 70orangeswinger
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Usually the factory clutch fan is adequate, do you have a shroud? A whole lot more questions to ask here, you'll need to give us a rundown of your combination for starters.
70orangeswinger
Well-Known Member
Factory shroud, new water pump, new fan clutch, new thermostat, new hoses. Timing is right on. Stock cam.
Did you replace the water pump with a six blade high volume water pump and is it a seven blade fan? Any work to the radiator? Does it have air conditioning? I take that the parts replacement was to combat an overheating problem?
Has it always done this? If not what has changed.
70orangeswinger
Well-Known Member
six blade pump, 7 blade fan, 3 core radiator. All to combat overheating. Had the engine rebuilt about 500 miles ago. Engine runs around 210 to 215. Didn't run hot till rebuild.
Normally, I say to run a hot compression test and post your numbers. But if you haven't tried it yet, this may drop you to a little more comfortable level.
WaterWetter®
WaterWetter®
Run it. If its not boiling over.
If its boiling fix whatever isnt holding pressure.
Heater core intact?
Vacuum leaks?
Carb lean?
Timing late?
If its boiling fix whatever isnt holding pressure.
Heater core intact?
Vacuum leaks?
Carb lean?
Timing late?
16 lb cap?
Probably wouldn’t hurt to read the plugs to see if your running lean, but I usually don’t start to get nervous until temps hit 220 as long as it isn’t boiling over. Make sure the timing isn’t over advancing at cruise rpm. There was a fixed 7 blade 17 inch factory fan but I don’t really think it’s going to make a difference if you have a new heavy duty fan clutch. As posted before, a small vacuum leak could easily lead to the same overheating condition, too.
pishta
I know I'm right....
run it with a 16 lb cap and good hoses. IIRC my work truck runs 220 stock. 16 psi is 260F boiling point of straight water, 267 with coolant. old school was 180 but that was why old motor didnt last 100K miles..lots of cylinder wear.
70orangeswinger
Well-Known Member
I will check everything that was suggested to me by everyone here. I am starting to lean towards the carb because if you are cruising and step on it a little it acts like it is running out of gas till I nail it and then it comes alive.
Do not run a fixed fan!
That’s going backwards making the engine work harder robbing HP.
That wasn’t good advice.
Check timing and jetting.
That’s going backwards making the engine work harder robbing HP.
That wasn’t good advice.
Check timing and jetting.
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