[CougarMike68]

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:

http://www.flowkoolerwaterpumps.com...ord,-Mercury<br>(1965-1977)/product_info.html

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

 

[XR7-Gina]

The pump may be making the water flow too fast not allowing enough time for heat transfer in the rad. I would stay with the 180 stat as well. Try water wetter, it will bring down the temp by 20 degrees +/-.

 

[lewpoberezny]

Make sure you did not accidentily get a reverse rotation water pump.

 

[67MercCat]

also make sure the thermostat is installed in the right direction.

 

['69cugr]

what the heck is "water wetter" ?

 

[jcbingcougar]

what the heck is "water wetter" ?

It's a synthetic additive. See info here: http://www.redlineoil.com/Products.aspx?pcid=10

 

[CougarMike68]

Thanks for all that feedback guys - great to have you 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 thermostat to be installed correct (I swapped it several times and I know which way in). Waterpump 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 Cougar cast iron 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

 

[Bad69cat]

Mike, I'd do a pressure test on your system first? If it does not hold 15 lbs or so for awhile you need to figure out whats up...Sounds like you are losing it somewhere....? (Your hoses should feel firm and stay that way foe awhile when hot)

 

[ClawIt]

The FlowKooler high volumes require the spring in the lower radiator hose or the suction could collapse the hose.

 

[CougarMike68]

The system is under full pressure and I checked the hose already .. it does not colapse. Unfortunately my idea that the winged wheel might be not fully on the axle is not correct - there is only little space.

Back to zero :-(

Mike

 

[Bad69cat]

I wonder if your radiator is plugged up/not flowing well then..? Seems like the only thing left

 

[FastbackAndy]

What else was done or changed when you put this on the car? Were the head gaskets changed by chance?

Greetz from Bamberg ;o)

 

[Bad69cat]

What else was done or changed when you put this on the car? Were the head gaskets changed by chance?

Greetz from Bamberg ;o)

It is very easy to get them backwards.....and will cause overheating too.

 

[woodsnake]

It sounds to me like you have air in the system....Did you drill a very small bypass in the "top" of the T-stat? A small hole will allow trapped air to escape properly. This is a very old, very simple trick that saves a LOT of headaches.

"It never sticks to any temperature, seems to go somehow up and down "

 

[67BlueXR7]

It sounds to me like you have air in the system....Did you drill a very small bypass in the "top" of the T-stat? A small hole will allow trapped air to escape properly. This is a very old, very simple trick that saves a LOT of headaches.

"It never sticks to any temperature, seems to go somehow up and down "

That's a new one on me, never heard of that being done before. Sounds like a great trick

 

[CougarMike68]

I did not change the heads or head gaskets - just removed the intake manifold, cleaned it and putted it back on with propper gaskets. I´ve added some stronger valve springs along with the Thumpr - thats the only thing I did in addition to the waterpump and camshaft.

Just that I get it right ... would air in the system prevent the thermostat from opening ? Would this air really stay in for weeks and some hundereds of miles ?

How small shoud such a bypass hole be in the thermostat ?

Thank U so much !!!

Mike

 

[woodsnake]

The problem with air, is that it gets trapped, and so will stay for a very long time......The small (1/64th) hole will the air get past the T-stat, and then vent as it should. There is only supposed to be coolant for for the impeller to work with.

 

[CougarMike68]

ok, as my waterpup is off I´ll go for that hole. I´ll reverse flush radiator and engine next wekend to see how good the flow is. First air then water.
I´ve never seen an "open" cooling system operating but expect that there is not an extreme flow as the opening of the thermostat is pretty small. Anyone any experiences !?

Mike

 

[CougarMike68]

Here comes a picture of my old waterpump (inside without backplate). It was not that bad just had a leaking seal, has been sitting outside for some months now.

Mike

 

[CougarMike68]

Hey ... I remember having disabled the distributor vacuum control valve some weeks before I swichted the cam as the replacement vacuum advance just had a single port. How likely is that this causes the problem ?

Mike