OK, I'm breaking the cam in in my rebuilt 302 in the Ranchero, but the engine temperature gets very high after about 10 minutes running (needle at the end of the scale). I know the engine will be a bit tight and some folks tell me this is normal during breaking in, but it makes me nervous!
I'm running a mechanical 13" fan, a reconditioned radiator and stock water pump. The temperature sender was matched (in resistance) to a stock 57 Ford Y-block sender so should be matched to the gauge. The engine is a 1979 block and the water pump is a NOS item for a late 60's engine.
Anyone got any advice? It scares me to death when that needle starts to climb!
What's the fan to radiator clearance? I would try and and keep it to an 1" or slightly less.
Are the pulleys original to the engine to?
Clearance between fan & radiator is about 1/2" to 3/4", the pulleys are billet aluminum vee-belt type.
I would measure the coolant temperature. My car's gauge will be at the very top of the range at around 190 degrees F. I have a Stewart Warner mechanical temperature gauge for actual measurement.
A 13" fan seems small. Weren't the 302-351 fans around 17"?
Yes, I would verify the actual temperature with a mechanical gauge.
Sometimes those Windsor type engines have difficulty getting all the air out of the system. Have you run it without the radiator cap off and checked for flow? Sometimes getting the air out helps with the cap off also.
Unfortunately a fan any bigger than 13" hits the top radiator hose so the only other option would be an electric fan in front of the radiator.
I haven't tried it with the radiator cap off, I'll give that a go. Someone also suggested taking the thermostat out while running it in.
Another thought is timing? I'm sure you set that.
I would never recommend removing the thermostat unless it was installed backwards or sshowing no sign of opening :003:
Another thing to check if the other recommendations do not cure your possible overheating is making sure you did not install a reverse flow water pump. Some 302 water pumps are a reverse flow. I had a friend install that one by mistake on his and it ran hot. A temperature gauge is a must to determine true temperature, even if you install one temporary. Good luck in your process of elimination.
Quote from: Wirenut on 2017-07-03 21:27
Another thing to check if the other recommendations do not cure your possible overheating is making sure you did not install a reverse flow water pump. Some 302 water pumps are a reverse flow. I had a friend install that one by mistake on his and it ran hot. A temperature gauge is a must to determine true temperature, even if you install one temporary. Good luck in your process of elimination.
Thanks, how do I identify a reverse flow pump? The engine is a 1979 block, the timing cover is an early one with the dip stick in the front, the water pump was a reconditioned one advertised as being for a mid to late 60's Mustang. I have got a serpentine belt pump in the garage and they look quite different, were reverse flow pumps also available for the earlier blocks?
Gary, the og 57 gauge is setup up for 170 degrees F in the middle. when the needle is to the full right of the black area that is only 200F. I would recommend adding a mechanical temp gauge and reading the actual waterneck and radiator temps with a hand held infrared thermometer.
The reverse flow looks the same as regular flow direction, I believe they came on the cars with serpentine only. They will bolt on just like the v belt pumps. Other than the impeller vein inspection you would need to remove your thermostat and while your system in circulating verify flow direction. You should confirm your overheating with a temperature gauge first though and then move toward the other recommendations. the infrared thermometer recommendation it a good way to check too as ford man jack said. This will let you know if the motor is actually overheating and will also confirm if your radiator is circulating properly before you start chasing rabbits.
get an infrared heat gun, point and shoot. tells all. look on both sides of the thermostat, top and bottom of the radiator. much more accurate than a gauge.
Thanks for all the advice, I've ordered an infra red heat gun, it should be here in a couple of days, I'll check various areas and report back/
Gary
While you are breaking in the cam, you might want find the biggest house fan that you can find , mount it on a chair or whatever in front of the car , plug it in and run it. This will put some extra air onto the radiator while you are racing the engine. Jay
I like the idea of having a separate water temp gauge with numbers....we added a second one on our TBird under the dash so we'd have a better idea of the exact temperature. Also always be sure that the upper radiator hose doesn't hump up above the level of the radiator cap; otherwise you can get an air bubble in it even when the radiator looks like it's full. That can make the temp shoot up really quickly.
I use the heat gun to verify what the actual temperature is with respect were the gauge is reading. Once you establish were "normal" is it is easy to keep track of. Unless you purchase a mid - high end mechanical gauge the electrics out there are subject to the same "electrical" glitches as the stock gauge, ie, grounds, connection corrosion, voltage source, etc.
Best example I can offer is my 66Falcon Ranchero with a 302 EFI engine. The stock engine (200) ran with the temp gauge on the low end of the normal line. The 302 ran on the very high end of the normal. The sender from the 200 was put in the 302. Got a heat gun and measured the temps as I thought I was running hot. The 200 had a 180 t-stat, the 302 had a 195 t-stat. Turns out the temperature was dead on, it was just the range of the temp gauge was very sensitive in the "normal" range.
My take on temps is "If it ain't losing water it's not hot"! Just like to know where it is.