Water Temp Questions...
 

Rebuilt the waterpump on my 30 Sport Coupe this weekend. Also installed a water temp gauge using a water outlet neck adapter. Filled the radiator with almost three gallon of mix, cranked it up and it spit out less than a quart, but no leaking pump!!!


It ran around 190 degrees at 45 mph, it was sunny and 61 in Raleigh (sorry for you northerners) and crept up to around 205 at 50+. Still very new to model A ownership, and am wondering if this is in the normal operating spectrum?


Also the gauge is from Bratton's "Rex-a-Co", most posters seem to like this suppliers, wondering if anyone has any feedback on this gauge...

Re: Water Temp Questions...
 

That's high. Shouldn't have gotten any higher than 170-180 in those temps I'd say. However, as long as you don't lose more coolant it won't hurt to run it as it is. In the summer you're going to have trouble though.

Re: Water Temp Questions...
 

Those temps do seem high. You may want to verify the temperatures with a cooking thermometer or an IR gun. My temp gauge reads high.

Re: Water Temp Questions...
 

Could be a partially plugged radiator. Most are.

Re: Water Temp Questions...
 

could also be slow timing.

Re: Water Temp Questions...
 

I agree with all of the above.

What were the symptoms before you did the rebuild? Were the temps higher lower, the same?

Re: Water Temp Questions...
 

FYI, my stock engine runs 150-170 depending on time of year. Had it out the other day in 40 F and temp was about 135-140 max.
Are you running straight water or with some anti freeze (curious) I have a laser temp device gauge from O Reilly's, the upper 1/3 of radiator runs about 10-15 warmer than the bottom half.
When on a tour with the group I always bring the temperature gone alone and shoot their rad temps when we stop. Most are around around the 160-170 temp.
If you are using straight water only, I would suggest maybe using Water Wetter in the rad, just my suggestion. We had a chemical engineer give a talk at one of our tech evenings. His thinking was straight water in the summer with Water Wetter and half anti freeze and water in the winter. Our club is in Canada, hence the anti-freeze as a precaution.

Re: Water Temp Questions...
 

An important fact: Not all temp gauges are not all calibrated. My temp gauge runs 13 degrees higher than actual temp. I used a laser heat gun from Harbor Freight to measure the actual temp. I now automatically subtract the 13 degrees from the temp gauge reading for an accurate reading.....

Re: Water Temp Questions...
 

Had been running hot before but assumed it was water loss since the Waterpump shaft was so badly scored. I ran Preston Radiator Flush thru the system for a couple of weeks, (maybe 50 miles), when I drained the system it wasn't terribly cruddy, but flushed Radiator and Engine with water hose until clear ware ran through. Went back and double checked and fan belt was not as tight as I think it should be, adjusted that and will see if it makes a difference. I'll try to validate the Temp Gauge with an additional thermometer this week...


Thanks for the input..

Re: Water Temp Questions...
 

I'd say that overtightening the fan belt is the most common error made by Model A owners. I leave mine with a good 2" of free play when I "wiggle" the belt on the long stretch between the water pump and the crank on the RHS. If I try turning the fan by hand, it takes little force to turn it - no chance of turning the motor over. I've seen too many water pumps and generators ruined by over tightening the belt.
The beauty of the Vee design of these belts is that as load comes on them, they automatically grip more - no need to run them tight.

Re: Water Temp Questions...
 

Your radiator is plugged. Common problem. If you can run 45 mph for a solid ten minutes, with no coolant loss, leave it alone.

Re: Water Temp Questions...
 

Let us know what you find as you are not alone with this issue.

Re: Water Temp Questions...
 

How familiar are you with setting the timing on a Model A engine? If it is set too retarded it will cause overheating and no amount of cleaning etc... will rectify its running hot.
Prestone radiator flush is targeted at hard scale type problems. Grease from too much lubrication of the water pump might be causing issues.
Try flushing the system with Simple Green. I would remove the radiator, plug the lower outlet and over flow tube and put 1 gallon straight Simple Green in it. Cap it and slosh it around. Let it sit for a while and slosh it around again. Do this for a couple of days and see what comes out. You might be surprised.

Re: Water Temp Questions...
 

Too bad you don't have a temp reading on the gauge prior to the water pump work. the temps are somewhat High! Fixing the water pump, I venture, has nothing to do with the engine temps. If the Radiator is original the gauge may be reading accurately. Gotta use another method of measuring water temp as close to the gauge point as possible. If both read high, ya got a radiator flow and cooling issue. If not and the alternate method reads below 180, then it is the new gauge reading high. Personally, I hope it is the gauge!

Re: Water Temp Questions...
 

IMO, far too much emphasis is put on timing the engine. There have been nearly as many threads on that as "What oil do you use?". Stetting the timing when the engine is stopped is only the starting point. What counts is the timing when you are going down the road and the optimum timing varies with speed, load ,mixture (GAV setting) and more. What is FAR more important is being able to determine where the sweet spot is when driving and that comes down entirely to the ability of the driver. After all, it is he and he alone who controls the timing, not the initial setting. Sure, the Intitial setting needs to be close but it's not worth fussing over obsessively.
To find the sweet spot, you need to be able to listen to the engine - not just hear it but LISTEN. As a rough rule, try advancing the timing till the motor starts to feel harsh, then back off till the harshness disappears (a notch or two). Once you find the sweet spot, there is not much need to change it till you want to start the motor again. If your motor has a high compression head and/or modified cam, it becomes more sensitive to the timing so you will likely have to constantly fine tune it.
1crosscut, I agree with what you say so long as you are referring to the timing while driving.

Re: Water Temp Questions...
 

My radiator was horribly plugged, not to mention several tubes which had been severed and soldered. My engine was routinely overheating and the radiator looked so shabby I didn’t want to put it back on the car when I did my restore. Radiators are expensive suckers but a new one now keeps it cool. Rarely above 180, and in weather with ambients less than 60 or so, The gauge hardly comes off the bottom end. Actually, for winter I put a thermostat in the upper hose to get the temp up to 165. Otherwise it just doesn’t want to stay warm