Reverse rotation water pump and timing cover

[mustangxtreme]

I have noticed as I search the web there is a lot of confusion about reverse rotation water pumps and the timing covers used with them. I have an 85 5.0 from a Crown Vic police car that I thought was using a reverse rotation pump. The pulley on the pump is smooth not ribbed and yet the timing cover has the same configuration as the clockwise rotating pumps. My question is do you need a new timing chain cover? Both covers bolt to the block the same way and water flows into the blocks from the same location. Based on what I can see a reverse rotation pump should work on an older timing cover. If I am off base please let me know. I need to figure this out before I get my motor put back together

Thanks

Dave

[allenpul]

as far as i know the covers are the same. There are some later models that have curved water ports but as far as the block cares it just needs water....

[LiLJoe306]

I think 79-85 are all standard rotation pumps. Either a reverse or standard will fit, what matters is how the belt is routed around the pulley. Reverse rotation goes on the underside of the pulley. Standard goes on top of the pulley.

[FoxChassis]

serpentine belt = reverse rotation water pump

[mustangxtreme]

Thanks for the replies. They help relieve my worry. I don't feel like going through another head gasket change.

Dave

[bigjason_5]

The timing covers look the same, but they are not. They will both bolt up to the same block, but will not bolt up to either water pump.

Here is a standard rotation water pump timing cover:

https://static.am-autoparts.com/item/a70d00bbc3.jpg

And here is a reverse rotation water pump timing cover:

http://www.allstarperformance.com/im...0/ALL90014.jpg

Notice the difference in the directions the coolant ports go. The parts are interchangable; but timing covers, water pumps, belt systems and fans have to be matched together.

[JACook]

Jason, I think you've got those links reversed. The first link shows a cover for
a reverse-rotation pump. <edit> That cover is an aftermarket replacement,
and is different from the production cover used on Mustang up through 1993.
</edit>

Up until '93, the Mustang 5.0 indeed used the same style cover whether reverse-
rotation or standard-rotation pumps were fitted. They use the same water pump
to timing cover gasket as my '65. Only major difference was the EFI cover did
not have the fuel pump pad.

The water pump itself is kinda football-shaped and also appears to be the same
casting for both standard and reverse rotation. I believe they did use different
impellers though.

Probably not the most efficient way to do things, but I'm sure it kept the bean
counters happy...

<edit again>
In the interest of science, I pulled the water pump off my '93 LX 5.0...



I also pulled the plate off the back of the water pump, and satisfied my curiosity.
The reverse rotation pump is not the same casting -internally- as the standard
rotation pump.

</edit again>

[bigjason_5]

Yes, the Mustang used the same style timing cover from '79-'93, with the only change being mechanical fuel pump vs. EFI. That's because ALL 5.0 Mustangs from '79-'93 had a serpentine belt and hence had the reverse rotation water pump. Other Fords, or '78 and earlier Mustangs, when equipped with V-belts, used the standard rotation water pump and timing cover. The pictures in the links I posted are represented correctly. The reverse timing cover picture I provided looks exactly like the timing cover on your '93, as it should since your '93 would have a serpentine belt and reverse rotation water pump. A standard rotation water pump will not fit, and would require a timing cover like in the picture I provided for a standard rotation timing cover.

If the timing covers in the links are aftermarket, it is only because they were the first ones I found to Illustrate the differences. They look exactly as the Ford timing covers do, in regards to the water pump rotation specific coolant passages.

[JACook]

The point of the photo was not whether or not the '93 is serpentine, but rather
to document exactly what a '93 HO cover looks like, and to show that the '93
"serpentine" front cover is really not correct for the reverse-rotation pump.

Look at that photo, and visualize a water pump spinning counter-clockwise.
Do those ports -look- like they're pointing the right direction? They're not.

The area where the water pump mounts on my '93 looks just like the cover
on my '68 Mustang, my '79 Fairmont, and the spare 302 I have out of a non-
serpentine '84 Grand Marquis. It looks almost the same as the one on my '65
Mustang, but IIRC, the '65 and '68 pumps don't interchange.

The point I'm trying to make here is, there is nothing special about the timing
covers used on the Fox Mustang. They're pretty much identical to the rest of
the Windsor timing covers that came before them. You can see the cover on
my '93 even still has the threaded holes for the short bolts next to the coolant
passages, that were used with the earlier standard-rotation pumps. The later
football-shaped pumps, like the '93 reverse-rotation pump, do not use these
holes.

If you would like to see a photo of my '93 with a '68 pump bolted on, that could
be arranged...

[wman24]

I would like too see pic, as far as I can tell timming covers are the same just pump housing and impellors are different. I thought cover was same because which ever pump and drive belt combination you have the coolant still flows the same way, its reverse rotation not reverse coolant flow or am I wrong?

[wgt500]

By the way '79-'85 water pumps are bi-directional pumps eventhough Ford runs them in reverse direction. It wasn't till '86 that the impeller, true centrifugal design, was strictly reverse flow. If you have problems with this check out flow cooler's website. They offer a good description. The radiused entry into the timing cover doesn't make the water flow any better since the cover on the back of the water pump has round holes and blocks most of that entry radius, but the pics. in the links are backwards. wman24 you are correct.

[dy85merc]

I run a reverse rotation pump on a 427W with a 1974 timing cover, it cools just fine. I'm not saying they will all work, but in this case it worked. Good luck.

[Zephyr 351C]

and the spare 302 I have out of a non-
serpentine '84 Grand Marquis.

The 89ish 5.0 I got out of a Crown Vic had the about same serpentine setup as the one in my 79 LTD. The alternator, PS, and WP driven off one belt (both serpentine), with the AC and smog pump driven off another (serpentine for the 89, V belt for the 79).

All the panthers I've looked at had this arrangement.

The pictures in the links I posted are represented correctly.

Based on my 79 351W and 89ish 5.0 out of panthers (both standard rotation), and my 1990 F150 (reverse rotation), they're backwards.

[bigjason_5]

JACooks picture he posted of his timing cover is exactly the same as the one I posted as the reverse flow timing cover. He said my pictures were backwards too. Yet, he has a reverse rotation timing cover. How can his reverse rotation timing cover and my reverse rotation timing cover be identical, yet both of you still claim my pictures be backwards?

[JACook]

Whether or not the cover is used on a serpentine application is irrelevant. The
cover designs ideally would favor the proper flow direction, but that's not how
Ford decided to do things.

Visualize water being slung by a pump that's turning counter-clockwise. What
direction would the water want to go? Now visualize water being slung by a pump
that's turning clockwise. What direction does the water want to go?

Reverse-rotation pumps turn counter-clockwise. Standard pumps turn clockwise.

The cover that you called "reverse rotation", and the one that's on my '93, is
actually correct for a clockwise pump, and is the same as Ford has been using
since around late '65 or so. The one you called "normal rotation" is an aftermarket
cover, but it is actually correct for a counter-clockwise rotation pump.

I'm really not trying to confuse the issue, it's just kinda hard to explain...

[bigjason_5]

I had a 5.0 out of a '78 Mustang. It had V-belts, and a clockwise rotating water pump. I installed a serpentine belt and all the pulleys, and a counter-clockwise water pump. The counter-clockwise water pump, though it looked the same, would not mount up to the timing cover. The timing cover looked exactly like the cover in my link for the standard rotation timing cover, and it was the original Ford cover. I had to swap it. Yes, I agree that they "look" backwards. Centrifugal force would make what you are saying make perfect sense, but Ford did not do it that way. And actually, if you look at the pump, there is a steel plate on the back of it and regardless of shape or direction, the coolant is already being forced through a 90 degree turn (from going outward from the water pump impellar, it makes a turn and then enters straight through the timing cover and into the block). It's a 90 degree turm regardless of whether it then moves slightly up or down when going through the cover. The cover has a hurricane/typhoon type shape to it, but it really does not have much impact on how it works.

[Zephyr 351C]

http://www.allstarperformance.com/sp...ts/pdf/651.pdf

[allenpul]

http://www.allstarperformance.com/sp...ts/pdf/651.pdf

nice!

[JACook]

OK, to finish what I started, here's a photo of my '93 LX with a '68 water pump
bolted on. Note the passenger-side inlet.



The only issue I found was that the '93 bolts are a bit too long. But the pump fits.
And as I pointed out earlier, the '93 uses the same gasket as the '68.

Jason, I really don't know what was the deal with the front cover on that Mustang
II engine.