Pat 12 gets a nose job

[Tony Wheeler]

Hi Phil

I haven't learned how to split posts on MLU so I'll have to do it manually:

re: Your graph came out giving more information than mine because of the way you ordered the data to be graphed. Did you have to type all this data back in because or did you capture from the picture?

Something else I haven't learned is how to use chart functions on MS Excel. I'm still using the old school method - graph paper! Other times I just use plain paper and construct my own axes, which means using a ruler to mark scales and plot data, but for presentation I do it on MS Paint, using the cursor pixel position instead of a ruler. It means using a calculator to convert figures to pixel position, but I'm pretty handy with a calculator so it's a very quick method, esp. with my scientific calculator which stores data. I've had it for 20 years and I'm always using it for something or other, in fact I rarely leave home without it! It's a bit tragic, but I'm one of those people with numbers rattling around inside my head all the time! I daresay you can relate to that Phil. Unfortunately though I don't have the patience or aptitude to learn computer programs, and unless I use them regularly I soon forget.


re: Running the engine at 2000RPM it climbed to about 190F and on the water jacket sensors and about 205 on the top tank with IR gun, but no higher.

That's very encouraging Phil, hopefully it will do the job on the road.


re: Interesting to watch the temp gauges with the engine not running but the blower fan still on the engine continues to circulate, thermosyphoning causing good circulation.

I hadn't realized you were running a constant speed blower fan, I had assumed the engine fan was fitted. That's why I was disturbed by the temperature spike at 1500 rpm. It's a good idea though as it allows you to load up the cooling system. If the fan was fitted it would just maintain a steady 170F, which doesn't tell you much.


re: I need to check the pulley sizes back to the original engine on the Pat 12 engine just to be sure that in the process of swapping out the original unusable 216 engine for the one that is in it now that I didn't in inadvertently mess up both the water pump and fan speed.

If the radiator is in good condition you may find you can get away with the larger pulley, which would be highly desirable in terms of fan noise. However I suspect it may overheat in summer, because it's reducing not one but two variables, ie. fan speed and water pump speed as you say. It would be an interesting experiment though.


re: If the radiator is big enough there will be a delta change and should be a delta. There is also the obviously, as Tony points out, a speed through the radiator at which fluid is moving to fast for heat exchange to take place.

As you say Phil there HAS to be a delta, and there always WILL be a delta. However, my reference to high coolant speed through the radiator core was not to suggest it's a bad thing, but merely to indicate the difficulty in measuring delta when the value is small. That's actually a GOOD thing. Believe it or not, the aim with radiators is to MINIMIZE the delta, which is done by MAXIMIZING the flow rate, so the coolant spends the LEAST possible time in the core. This is why our brain hurts when we try to get our head around cooling systems. It's entirely counter intuitive, because we've learned from everyday experience it takes time for hot water to cool down! However, it's the RATE of cooling we need to consider, because it needs to keep up with the RATE of heating in the motor. We need to forget about TEMPERATURE LOSS, and think about HEAT LOSS, which is a different thing altogether.

I'll try to elaborate in a separate post, or maybe even start a separate thread, as it's highly relevant to flatheads.

Cheers,
Tony

[Phil Waterman]

Hi Tony

Going old school on graphing the data makes it even more interesting.

Agree on splitting the thread to put the cooling system discussion in one thread and the rest of the nose job in another makes senses, will see if I can figure out how to do it.

Worked yesterday and hope to finish today the water pump conversion. The directions with the conversion plate spend a lot of time on the fan/water pump speed. When I did this conversion on the 261 I did run the engine on the test stand with big pulley on the crank and a small one water pump. That combination seriously over speeded the fan. Particularly with the 6 blade CMP fan, which when you cracked the throttle sounded like a plane, with a really strong prop wash. Air flow was so strong that it was sucking oil out of the oil breather. Was really concerned about the fan failing from being overspeeded so swapped the pulleys around from engine to engine to get the speed down.

Now out to work on the truck.

Cheers Phil

[Bob Carriere]

I have a recorred 3 rows of tubes with the six blade fan..... no sheet metal yet except for the front fenders.

Not sure if I have the 216 I have the large 261 crank pulley front pulley but the engine maintains a steady 161.005 degrees F with the 160 thermostat. Double PH-8 spin on oil filters.

This Spring when we first took it out of storage is ran at about 900 rpm for nearly an hour to cook off any condensation then the oil was changed.

I drive it in the back field exclusively in low range ( t-case was changed to a 2 speed). Low range allows me to cycle/crash in all 4 gears when travelling on the paved road from the house driveway entrance to the back field lane.

On wide open throttle the heat damper on the exhaust manifold vibrates the little coil spring like crazy...need one of the antirattle spring..... the Carter YF carb sounds like a vacuum cleaner trying to suck tennis balls. Filling the bowl of the air filter with oil has toned down the sucking sound somewhat.

Never gets up above 161 F.

Cheers