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Engine running hot with flowkooler highflow waterpump

26K views 73 replies 31 participants last post by  GypsyR 
#1 ·
My 68/302 original waterpump leaked and I had to get a new one. I decided to throw in a CompCam Thumpr along with that work and to be safe with the maybe higher temperature I went with the folloging Flowkooler highflow aluminium waterpump:

289, 302, 351 Small Block Ford hi flow water pumps

Unfortunately since then my engine is running hot - at every speed. No matter if I go 30mls in the city, 50mls on country roads or 80mls on the autobahn.

I tried several thermostats (165/180/190°). It got better with the 160°F but the engine stays way to cold on short rides and cold days now.

Did anyone have any similar problem. Could there be a problem with that pump ?

Mike
 
#3 ·
Driving with 50mls on country roads drives the heat all the way up until the radiator boils. The TEMP indicator is all to the right :)

Do I need an upgrade for my cooling system to run a CompCam Thumpr ?! Never heared of it. I did not change anything else - dame carb and intale (2V).

Mike
 
#6 ·
OK, first, the engine was designed for best performance with the 190°F thermostat, so put that back in. You'll get more power, better mileage, and less sludge in the oil.

You had the distributor out when you did the cam. Check the timing. As little as 2° too much advance can cause overheating.

I don't bother with high-flow water pumps. The radiator is the heat exchanger. if it's not up to the job, you could have dual water pumps and it wouldn't help.
 
#7 ·
Will it overheat if you let it idle? When you installed the cam did you put the intake gaskets back in the right way? Did you put the thermostat in correctly? Did you adjust the valves too tight? Do you have air trapped in the system? Do you have too much or too little antifreeze in the system? And, like the others said - check the timing.
 
#9 · (Edited)
Thanks for all that feedback guys - great to have some experienced ford enthusiasts aside !

I´ve setted timing to basic 6 degrees and at my first rides even my vacuum advance did not work propperly (I repaired it later) so I only had centrifugal advance - no way timing was to early - definitely !

I expect the intake gaskets to be in correct, as well as the thermostat (I swapped it several times and I know which way in), valves are adjusted according to engine specs - not to tight but also not to lose. Did the adjustment many times before - never had a problem. No antifreeze, no air -definitely. Rotation is clockwise.

Here comes some more informations:
The engine is running hot at stop and go in the city, too, not sure if it would at idle. It never sticks to any temperature, seems to go somehow up and down "in cycles", increasing a few degrees at each cycle. It is always running hot in about the same timeframe - no matter if I go 100mls/hour or 50mls/hour. The only way to keep it cool is to switch to "neutral" when driving downwards or when approaching a stop/trafficlight - so the water/engine is cooled by air while not loaded. It runs hot at 68°F outside temperature as well as at 95°F.

Here comes a new hint:

Today I´ve been looking at the old waterpump and I saw a substantial difference to my new one. The impeller (winged wheel or whatever you call it) of the original waterpump is not only slightly bigger but fits way closer to the waterpump housing (towards the front of the car) than at the new one. Looks like the impeller is not properly pressed all the way on the cam. As far as I understand the water is sucked in by the impeller at the center of the waterpump, so this could be a problem - right ?!

Mike
 
#10 ·
I have a thumpr in my 351w, and I have been having problems running hot for months now. I was about to order a high flow water cooler to try and solve my problems. After running across this thread, I decided to take a closer look at my timing. For the entire time I have been having my overheating problems, my timing has been set at 12*-16* base (idle), but after reading this article:

Where should I set the timing on my performance engine?

I decided to focus on my total advance, rather than my base timing. After setting my total advance to 36* (@3500 RPM), my base (idle) is now sitting at 21*

With base timing set at 12*-16* my temperature would always eclipse 245 *F in under 30 minutes, and I would shut down because the temperature was still climbing. Today I let the car idle for 1 hour with my new timing (21* base, 36* total) and it never climbed over 195.

I have some concerns with 21* base being too advanced, but I did not notice any knocking or pinging (using 87 octane, about 9:1 on compression) and I actually had better low end power on 20 minute test drive.

A) Does anyone think I should be concerned about being so advanced at idle?
B) If not, then perhaps Mike just needs to advance his timing significantly
 
#12 ·
I have advanced timing already as the Thumpr nees some more advance for maximum power. More advanced timing did neither solve the problem nor made it worse.

I have removed the waterpump yesterday, take some photos of the winged wheel and send it Flowkooler to see what they think concerning the distance between the wings and the housing. This distance even has specific values shown in the service manual for the stock waterpump so it will be important.

Mike


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#14 ·
I suspect your radiator is clogged. Some gunk in your cooling system probably dislodged during your water pump/cam change out and clogged the radiator.

For some reason, whenever an engine is overheating, people try everything else before checking the radiator. Typically, the radiator is the problem so I always check that first.

It's very easy to pull the radiator and have it checked by a good shop. Then you'll know for sure. If it's clogged, they'll fix it. If it's not clogged, you can check off the radiator and move on.
 
#18 ·
Hi guys thanks for all that input !

1. Radiator: W´ve already checked it but I´ll cross check to make sure noting blocks water flowing. Unfortunately radiator service is quite rare here in germany. They use to swap parts here these days :-(

2. Backing plate - sure - it is on - needs to be on.

3. Timing
Does late timing run an engine hot ?! I always thought early would do so. Timing had no significant effect on temperature - at least in my actual setup.

Mike
 
#22 ·
The hose does not collapse -I checked it by rving up the engine and therefore waterpump speed and looked at the hose - no change in shape. I´ll order a spring anyeay to be safe fore the future :)

OK, timing is a critical point but as I stated before - I went with 6° and 15° - no change. The engine is running up - no matter if I cruise or race - always in about the same time.

I´l reverse flush the radiator and engine next weekend any may do a video if I have the time and equipment and post it here.

Mike
 
#23 ·
Have you measured the temp with any other gauge besides the stock gauge? I started having overheating issues and it turned out to be my stock gauge was just acting funny.

A clogged radiator would also be my first guess. The flush should help out or at least give you an idea of what is going on with it.
 
#30 · (Edited)
My initial thoughts exactly. With the radiator cap removed and engine running at operating temps, is the direction of water flow across the radiator from left to right?

Make sure the pump they sent you isn't for a late model 5.0L, like pictured below

 
#27 ·
Kind of a strange test; if you can get the rust off, try the old pump again. But only if you can clean it up because you don't want that junk in your system. Since that's the only change you've done, it is a good part to start with. If it runs cooler, there you go. If not, lots of good advice has been given. Me? I would start with the radiator if the old water pump didn't show a change. In all my years of playing with Mustangs and Falcons, that's where the problem usually starts. When you get it figured out, I highly recommend a Gano (or equivalent) coolant filter. It goes into the top hose and stops all the radiator and heater clogging chunks completely.
 
#28 ·
Besides the cam the engine is stock - correct. Never heared of any necessary additional change besides stronger springs for a CompCam Thumpr. The Cam is not to sharp. What kind of promlend did he have ?!

Unfortunately I cannot try the old waterpumt - is was leaking heavily and this was the reason for the "upgrade" to Flowkooler highflow.

Radiator - yes I will test it !
 
#29 ·
Just throwing another idea out there. I don't know the specs. of your new cam but have you rejetted the carb to add more fuel. Your cam probably has more lift which puts more air into the cyl. , now you will need to put more fuel in to keep from running too lean. Lean is mean but it also causes more heat, and too lean can cause overheat and engine failure. Just my .02.
 
#33 ·
This worries me too.

I think your cam is woefully mismatched. Did you say you're still running a stock 2bbl and intake? I think you should go back to your stock cam.
 
#31 ·
This thread is amazing !!!

I would never have thought that there are so many things that could cause an enginge running hot ...never.

I did some changes on the fuel - yes. I´ll give it a try if radiator and flasing fails. The direction is clockwise - so is my old waterpump (see picture above).

Mike
 
#32 ·
If the pump looked that bad when it came out then maybe you DO have some obstructions in the radiator. You can try removing it and laying inlet/outlet up on a flat surface and letting a caustic solution soak, then drain and flush with a hose if you can't find a shop to clean it.

No, early timing will not cause overheating. Quite the opposite, especially at idle; advanced timing aids cooling. You can't "over-advance" the timing enough and still be able to drive it without detonation or preignition to cause excess heat. Now, as far as late timing is concerned, you betcha.

When you installed the new camshaft how did you index it? I looked at the least aggressive grind, the 279TH7, and it indicated that the cam was already ground 4 degrees advanced so if your cam gear had multiple keyways I would have used the TDC one.

How about the break-in procedure? I see Comp says on dual valvespring applications to remove the inner spring for break-in so the lifters can rotate freely. Don't know of your head set-up.

Also, Comp recommends valve adjustment as zero lash plus 1/2 turn. An extra 1/4 or 1/2 turn could result in valves that are not seating completely which will also cause overheating.

Just some additional things to think about.
 
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