Spent some time researching the water pump rotation saga…

Stever89 · Jan 18, 2011

This came about after discovering my 302 firing order was of the 351W/302HO configuration. That led me to research what the differences are between the 302 and HO, and that led me to discover the HO was nothing more than a roller block with better heads and intake, and later a serpentine setup. When the serpentine belt came along, the new belt routing changed the water pump rotation which changed the pump itself, and that forced a change to the timing cover.

I’m sure I’m really abbreviating this, but I think that’s the gist of it anyway. I was on several Mustang forums, Ford forums, Ford Truck, Bronco, you name it. This seems to be an elusive and confusing subject.

So now I go out and look at the front of my engine (my Fox is a former 4, so I have no idea what the motor is), which has had a chronic overheating problem since I got it last year. It’s a roller motor for sure, carbed with electric fuel pump, 1-3-7-2-6-5-4-8 firing order, with the serpentine setup. I look closer at the timing cover, it’s the earlier cover that takes the standard (clockwise) rotation pump, but the pump seems to be the newer reverse rotation (has only two bolts per port instead of 3). If it isn’t a reverse, that’s even worse, at least a reverse could be installed and made to work with an adaptor “universal” plate. I grabbed a magnet, the pump is aluminum and sticks to the plate, so I know it’s there too.

So where do I go from here? I guess I replace the timing cover for one that is supposed to take a RR water pump, no mechanical fuel pump and no dipstick hole (this motor has one on the driver’s side).

If anyone’s got any experience with this, I’d sure like to hear your stories or advice.

mwood · Jan 18, 2011

If you look on summit, those timing covers work on 302's from 68 to 93. Other than pump and dipstick, I'm not sure there is a difference. You might not need one. Be sure you do before forking over the dough.

90FoxBdy · Jan 18, 2011

Any part numbers on the water pump? Could you be spinning it backwards?? (You have a standard rotation that you are spinning backwards....vise versa)

Stever89 · Jan 19, 2011

90FoxBdy said:
Any part numbers on the water pump? Could you be spinning it backwards?? (You have a standard rotation that you are spinning backwards....vise versa)

I don't have a number, but that's what I'm afraid of... I know that cover is the wrong one for a reverse rotation pump, so I have a feeling it's coming off.

90FoxBdy · Jan 19, 2011

If you are going to remove it, just take the pump off first. You can remove the back plate off the pump to figure out which way the pump should be spinning by looking at the fins. Sometimes taking the timing cover can be a pain when it comes back to sealing the oil pan up using the cork tabs provided with the gasket kit. Give us an update when you pull the pump off. If you find you were spinning the pump the wrong way there are still some options, depending on what accessories you have. I run a standard rotation pump on my car with no issues.

Stever89 · Jan 19, 2011

90FoxBdy said:
If you are going to remove it, just take the pump off first. You can remove the back plate off the pump to figure out which way the pump should be spinning by looking at the fins. Sometimes taking the timing cover can be a pain when it comes back to sealing the oil pan up using the cork tabs provided with the gasket kit. Give us an update when you pull the pump off. If you find you were spinning the pump the wrong way there are still some options, depending on what accessories you have. I run a standard rotation pump on my car with no issues.

Will do and thanks. You can take that back plate off relatively easy?

dagenham · Jan 19, 2011

The dipstick hole and opening for the mechanical fuel pump are the only differences. The holes for the cooling are all the same.

ashford · Jan 19, 2011

oh the joy of 80's timing covers.
ford used the same basic casting for timing covers from somewhere in the late 70's to 87 or thereabout. variations included dipstick hole, wheter or not the the fuel pump hole was knocked out(cast in blockoff, just need to cut it out) and i think some later ones had an extra threded hole. this one can accomodate a normal or reverse water pump. the problem being that the sealing surface of the gasket wasn't a good match for the reverse pump and was really thin, when they got age on them they liked to leak so around 88 when all of fords sbf's had reverse waterpumps they revised it with no fuel pump provisions and matched the wateroutlet shapes to the newer pump.

just because it has a serpentine belt does not make it reverse rotation, if the belt contacts on the flat side it is reverse. many early 80's cars had a serpentine that was manually tensioned and rotated normally.

also(correct me if im wrong) the standard and reverse pumps had a different bolt spread on the pulley

mob · Jan 19, 2011

Check out my thread I made a while ago on using a standard pump on a reverse rotation timing cover. It has pictures that may help give you a better idea of whats going on.
http://www.stangnet.com/mustang-forums/789673-running-standard-water-pump-stock-timing-cover.html

If it is a roller motor than it should use a reverse rotation pump unless someone changed the timing cover on it. You wont be able to tell which water pump is which by looking at it from the front. You will need to take it off to tell which pump and cover you have. You can only tell by looking at the port shape on the backing plate, but once you get that far you mine as well replace the pump, and in that case just replace it with the correct one. The standard rotation pump also uses a water pump pulley that has a much smaller bolt pattern then the reverse rotation pump but without seeing them side by side it may be hard to tell which you have.

What accessories do you have? Which way are you spinning the pump?

Stever89 · Jan 20, 2011

ashford said:
oh the joy of 80's timing covers.
ford used the same basic casting for timing covers from somewhere in the late 70's to 87 or thereabout. variations included dipstick hole, wheter or not the the fuel pump hole was knocked out(cast in blockoff, just need to cut it out) and i think some later ones had an extra threded hole. this one can accomodate a normal or reverse water pump. the problem being that the sealing surface of the gasket wasn't a good match for the reverse pump and was really thin, when they got age on them they liked to leak so around 88 when all of fords sbf's had reverse waterpumps they revised it with no fuel pump provisions and matched the wateroutlet shapes to the newer pump.

This makes perfect sense, and further reinforces my suspicions. In my opinion, if you have a serpentine setup/RR wp, you need the newer RR cover. The older cover may accept the RR pump, but the water flow is restricted due to the ports on the older cover being designed for standard rotation flow. This is what I believe is wrong with my engine. The motor runs cool on the highway in cool weather, but quickly overheats when parked (new fail safe tstat, new alum. radiator). When I take the tstat out, it runs much cooler. This is the way the motor was when I got it.

just because it has a serpentine belt does not make it reverse rotation, if the belt contacts on the flat side it is reverse. many early 80's cars had a serpentine that was manually tensioned and rotated normally.

also(correct me if im wrong) the standard and reverse pumps had a different bolt spread on the pulley

Correct and correct.

Stever89 · Jan 20, 2011

mob said:
Check out my thread I made a while ago on using a standard pump on a reverse rotation timing cover. It has pictures that may help give you a better idea of whats going on.
http://www.stangnet.com/mustang-forums/789673-running-standard-water-pump-stock-timing-cover.html

If it is a roller motor than it should use a reverse rotation pump unless someone changed the timing cover on it. You wont be able to tell which water pump is which by looking at it from the front. You will need to take it off to tell which pump and cover you have. You can only tell by looking at the port shape on the backing plate, but once you get that far you mine as well replace the pump, and in that case just replace it with the correct one. The standard rotation pump also uses a water pump pulley that has a much smaller bolt pattern then the reverse rotation pump but without seeing them side by side it may be hard to tell which you have.

What accessories do you have? Which way are you spinning the pump?

I ran across your thread during my massive web search this weekend. Good stuff. My situation is exactly opposite of yours, you had a RR cover and wanted a standard rotation wp, I have a SR cover (with what I believe) is a RR wp, and my motor is a roller, so I'm pretty sure someone put that older cover on. Why, I have no idea. If I had to guess, my engine is a Heinz 57, parts from whatever thrown together.

I'm just guessing here, but if you look at the older cover, you see 3 bolt holes per port.
View attachment 198641
The newer RR cover only uses 2 bolts per port.
View attachment 198642
so I'm thinking that if you look at my older cover/wp, and see only 2 bolts in that area, you have a RR pump.

Spent some time researching the water pump rotation saga…

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