Rover V8 & P76 Waterpump Seal

[enigmas]

I thought I'd start this thread as I have several spare water pumps for both my Rover/P76 V8 engines. As an enthusiast you're no doubt aware these engines share a common lineage having been originallly derived from GMs all alloy 215 ci V8 engine of the 1960s.

Having said that, some enthusiasts may not be aware that the water pump seals were and still are common to these engines, at least as far as the early 3.5 V8s fitted to P5s, P6s, SD1s, SE2s and the Leyland P76 V8s are concerned as AFAIK. I stand to be corrected by more astute individuals though.

I can have the pumps commercially rebuilt but this can often blow out close to $300 AUD or more if postage or much travel is involved. So I resolved to locate a source of suitable seals. Sounds straight forward until you try and find the source. It's definitely on the level of secret society handshakes as the rebuild companies try to protect their interests.

Well to cut a long story short, after a few days of research and numerous phone calls suitable replacement seal kits can be obtained (at least in OZ) from 'Davies Pool Pump' shops or suppliers. The seal is a common component used in these and many other pumps. The running/working faces are ceramic on carbon. The seal kit retails for approximately $25 AUD.

If you have access to a hydraulic press the rebuild process is straight forward. Here are the details of 2 suppliers in Victoria, OZ.

Preston Bearings and Oil Seals Pty Ltd
Address: 6 Orthla Ave, Heidelberg West VIC 3081
Telephone: [phone]
Fax: [phone]
E-Mail: [e-mail]
Business Hours: Mon-Fri 8:30am-5:00pm

HI Vince 
1     X      A6A-5/8 Mechanical seal            $21.86 + gst 
1     X      FPS61 (5/8) Universal water pump brg         $36.75ea + gst 

Regards  Rudi 

I purchased 2 seals from the company below as they were close to home.

[enigmas]

The first pump I want to rebuild is from the Rover SD1 engine fitted to my ZB Magnette Coupe.
Below are a range of images illustrating the component parts and 2 water pump housings (Rover SD1 and Leyland P76 V8.) Note the similarities. Both impellers of these 2 pumps are quite primitive in their design. I also have a new pump manufactured in Poland with a much more advanced designed impeller having more in common with an airfoil shape than a paddle steamer as in the earlier versions.

The images and information that follow are in no particular order but should be self evident.

PS. CORRECTION.
I must have had a senior moment as the dimension of the long shaft on the SD1 bearing below looks incorrect. Unfortunately it's now been binned. Not an issue though as I have 2 new 'universal' bearings on order. Both these have 2 1/2" shaft lengths at either end of the bearing. The excess can simply be cut off after fitting to the pump housing.



SD1 & P76 housings.
Note seal sitting on SD1 housing. Both pumps accept the same seal.


P76 housing on the left.


SD1 housing with seal in place.


SD1 Impeller. Note the crappy casting finish. Big chunks of casting beside 3 impellors.


Cleaned up SD1 Impeller (at red points)


Old and new seals



New seal components on the outside.
An old (but reusable 'thin') ceramic seal component in the middle.


Note:
The seals comprise 2 components.
One that fits in the housing (carbon faced)
The other (ceramic) that slides over the bearing shaft with its back against the impeller.

* The ceramic seal can be either thick (1/4") or thin (1/8") depending upon the application.
Either ceramic seal works against the carbon thrust seal fitted to the pump. When dismantling the pump it is worth retaining the ceramic rear seal. This provides 2 options. The ceramic seal does not appear to wear but is brittle, so treat it with care.

New seal components with another new packaged seal kit to the right.


The housing seal in profile.


The Rover Water Pump manufactured in Poland.


Note the improved design of the impeller

[3litrekiwi]

Hi Vince, was there a silicon carbide version of the seal available? When I was powder coating we went through a lot of pumps before changing to a type with silicon carbide rather than ceramic / graphite and never replaced another pump. The seals are usually a bit more than twice the price but would outlast the car. Just a thought. Most of our cars probably don't do much mileage so maybe not an issue. Australian Spa Parts do a 5/8" SiC seal but the other dimensions would need to suit. 

[enigmas]

Not that I'm aware Martin. Both pumps run very similar seals to the one I purchased. The ceramic and carbon running surfaces of the seals don't seem to illustrate any wear.

The pumps start weeping coolant due to degradation of the rubber/synthetic compound that house/bind the elements of the seal. Once it degrades (due to age, heat cycling, erosion wear, dirty coolant whatever?) the seal becomes compromised. This seems to be the fail prone element of the seal, not the carbon & ceramic running surfaces.

To be fair, the pump on the SD1 engine is the original unit...and it only started weeping after I pulled the engine for a light freshen-up. Just one of those things!

* I'll post related images of the parts/components of the SD1 pump as I rebuild it. There's a few things to be aware of when rebuilding the pump.

* One of the major changes to the SD1 pump body I use, is to reduce it's overall length by cutting the nose back and also dispensing with the original mechanical drive flange.

Note the carbon faces on both the old and new seals. The carbon face on the old seal is still in perfect condition.


Note the rubber layer around the back of the old seal has perforated allowing the coolant to escape past the seal and exit the pump weep hole in the alloy housing.

[3litrekiwi]

The silicon carbide seals usually have viton rubber elements so perhaps the most durable would be a seal with viton rather than butyl / nitrile regardless of the contact parts. This is a great thread, any new good quality seal well fitted will last many years/miles so a good bit of proactive maintenance given the age of our engines. Probably more so for cars that aren't driven regularly.

[enigmas]

Here's today's update.

Note the images below.
This is the bearing, seal and impellor from the SD1 V8 in my ZB Magnette. The bearing is shorter and the impellor has less physical mass to it but is fundamentally the same.



The pump bearing housing is slightly different internally from the one shown previously. The internal bearing housing in this pump body is reduced in length. The housing is slightly increased in diameter up to where the pump seal resides.


Note that carbon thrust of the seal works directly against a hardened steel sleeve not against a ceramic seal. AFAIK this is the original Factory seal and bearing.


Both bearings are Factory standard although one bearing (not shaft) is longer. AFAIK.




PS.
Later that day as I'd removed the existing pump, I thought I'd check to see whether the new Polish pump I had aside would actually fit onto the SD1 timing cover. As luck would have it, it went straight on! I was expecting the newer designed impellor to foul on the back of the timing chain cover but it cleared, even without the gasket. The only downside to fitting this pump is that I'll have to fabricate a pulley that moves the drive belt back. It does give me the option of another viable pump though.

[enigmas]

Update No.5
Yes this thread is growing like Topsy!

I found several more interesting things about the impellers and seals used on production SD1 Rovers.

The first pump I dismantled used a cast iron impeller (refer to previous pix)

The second pump I dismantled uses a light alloy impeller, a steel surface ring against the carbon face of the waterpump seal (not ceramic) and interestingly a cast iron splined insert within the alloy impeller. The bearing shaft is pressed into this.

Alloy Impeller and Splined Insert
The ceramic face seal was adapted to the impeller with some straight forward lathe work. By pure chance the ceramic seal and its rubber cup fitted perfectly into the cavity on the front face of the impellor. I increased the depth of the cavity in the impeller by 1.5 mm to seat the seal correctly. The pump seal is spring loaded so requires slight pressure against it, but it musn't be crushed! So take care with measurements prior to disassembly. The impeller blades clear the housing by .015" - 020" when correctly positioned. This dimension can  be checked using feeler gauges.


I took great care pressing the cast iron splined insert free of the alloy impeller due to the fragility of the latter.
This is the press I used for the dismantling and assembling of the pumps.


Here are some more pix illustrating the various bits and pieces and some of the small mods made to adapt the ceramic component of the pump seal to the impeller.







I had to cut this flange off the spline fitting after it was pressed into place.


Back of the Impeller.
I cut the flange off the spline fitting with a thin cutting disc in my trusty angle grinder, then the hack saw and finished it off by linishing it on my bench mounted disc sander.  


The impeller resting in place on the second pump. Now I just need to source a replacement bearing and this waterpump will also be done. Perhaps a lick of paint though to restore the aesthetics. 


Addendum
This is the above pump (the leaking pump I initially removed to repair, now a spare) refurbished with a new bearing and seal.

[enigmas]

Update No. 6
I put in a couple of hours work this morning cleaning the remaining gasket material from the timing chain housing and cleaning, prepping and painting one of my rebuilt pumps ready for reinstall tomorrow.
Whilst I had the pump aside on a bench drying I thought I'd fit the 'new' Polish pump just to illustrate how well it sits in place. Of course though, were I to use it I'd need to cut off the excess protruding bearing stem and fabricate a suitable pulley. Not a big deal...just a bit of extra work involved.

As I now have 2 rebuilt and suitably modified pumps that are directly interchangeable (for my V8 powered MG Magnette) there's no real urgency to do this.

[enigmas]

Update No. 7
This information below may prove useful to anyone who is considering rebuilding/refurbishing a Rover 3.5 litre or P76 V8 4.4 litre waterpump.

2 new water pump bearings arrived today by courier.
*Both bearing shaft/axle ends are 2 1/2" long
*The bearing itself is 1 1/2" long
*The overall bearing length end to end is 6 1/2" long.
*Stamped on the end of each bearing shaft/axle is the following: UBC - AUS FPS61



The following picture shows one of the refurbished pumps refitted to the engine



As a safety precaution I decided to lock wire the bolts that retain the pulley. The pulley is a slide fit (not a tight interference fit)