Machining a Cassette type water pump.

[kstrutt11]

After a deal of reserch In how to deal with my leaky water pump I have decided to make my own verion of a cassette type pump, three main reasons are, cost of the Burton set up (?500), wories about what happens if a an electric pump fails (cooked cylinder head?) and I have the machine tools and like a challeange!

I have a virtually perfect spare front cover and have drawn up a design which all looks like it will work pretty well, my plan is to use a standard bearing etc (as they should always be widely available).

I should have the material together next week and plan to start then.

Reading the old posts It appears this was widely done in the past anyway, does anyone have any pictures etc of this type of arrangement? (I would just like to confirm I haven't missed anything)

Kevin

[GrUmPyBoDgEr]

After a deal of reserch In how to deal with my leaky water pump I have decided to make my own verion of a cassette type pump, three main reasons are, cost of the Burton set up (?500), wories about what happens if a an electric pump fails (cooked cylinder head?) and I have the machine tools and like a challeange!

I have a virtually perfect spare front cover and have drawn up a design which all looks like it will work pretty well, my plan is to use a standard bearing etc (as they should always be widely available).

I should have the material together next week and plan to start then.

Reading the old posts It appears this was widely done in the past anyway, does anyone have any pictures etc of this type of arrangement? (I would just like to confirm I haven't missed anything)

Kevin

You say you will be using a "standard bearing" or do you mean "the standard bearing"?
I mention this because the Ford/Lotus bearing is the weak spot that causes all of the problems.
OK you will be able to change the bearing more easily but if you're designing & making your own set up it may be worthwhile selecting a more robust part.
Good luck with your project & sorry I can't provide the information you're looking for.

[john.p.clegg]

Kevin

I have an AKS front cover fitted but no spare cassette,have a block of ali in the shed waiting some downtime to go ahead....
Keep us posted

John

[CBUEB1771]

After a deal of reserch In how to deal with my leaky water pump I have decided to make my own verion of a cassette type pump, three main reasons are, cost of the Burton set up (?500)

I have both a Dave Bean and a Burton Kit. Both are expensive but awfully cheap compared to doing your own. I don't wish to discourage you, but making your own makes sense if you value your time at fractions of the penny per day and you are very skilled. The Burton kit is the way to go. You get brand new front and back cover castings, cassette, etc, etc. The Bean kit has a massively reworked old front cover: hacked, welded and re-machined until not immediately recognizable. I have viewed assembly of both with a local engine builder and sealing the Bean cassette is a total bugger, I would not waste my time, even after having spent money on the kit. Both Burton and Bean use the original bearing and seal system. My apologies to Elan Factory, I just have not seen one of theirs. No commercial endorsements, just my individual experience. In previous discussions people have expressed concerns for the future supply of cassettes and bearings/seals. The Burton front and rear castings are not likely to fail and their cassette is easily duplicated with a numerically controlled lathe and a vertical mill. Burton's seals are standard dimension o-rings.

If anyone wants my Bean kit i'll trade it for one Tanqueray martini, not just lunch at Tiny's.

[mr.vman]

Russ,
Not to cause problems but, I just purchased the Dave Bean "removable water pump assembly". All the castings are new, including the back plate. The removable water pump assembly is also new, and appears to have a larger bearing assembly and cast impeller. I see nothing that has been reworked or modified (no welds) on the assembly. The front cover looks as original, except for the screws holding the water pump assembly into the front cover. By the way, the front cover is also a new casting. The water pump can be removed in place by threading screws (stored in the pump flange) into the pump flange, acting against the front cover. The screws act as a puller removing the pump, a nice feature. Maybe this will help.
Steve Vukobratovich
Sierra Vista, Arizona USA

[stugilmour]

Hey Steve, hope the Plus 2 is going well.

I also wondered if Dave Bean's new cassette design was different than the original; I had seen previous posts that mentioned the limitations Russ outlines above. I know it took them over a year or two to get the revised product out, new castings, delays in machining details, etc. In the interim I ended up buying the Burton product instead. Sounds like a totally new deal that will work well.

Bonus if Bean's are going to stock the spare pumps or if they are a common replacement part; the Burton pump shows as a special order item in the catalog, and I ended up waiting several months for the pump portion of the kit. I bought two to make sure I had a spare; belt and suspenders I guess.

The new Burton will be installed in the next couple of weeks, so will know better if any sealing issues etc.

Cheers!

[Jas]

Hi Kevin

Consider buying a X-flow water pump and split the housing to use the axle, bearing and impeller assembly. The bearing is larger and the impeller and axle is the same. Since you are making your own housing, it?s easy to make room for the larger bearing.
A friend of mine has done this modification to the Burton kit, so there is also room for it there.

[CBUEB1771]

All the castings are new, including the back plate.

Could you post an image of your Bean front cover? I wonder if they are now re-selling the Burton kit. I got my Bean kit in the past two years, it was back-ordered for nearly a year. My Bean back plate is new, machined from plate stock. My Bean front cover is, as I said, an amazing bit of agricultural hack work. I'll take a couple of photos of my Bean kit tomorrow and post them.

[gerrym]

Kevin, re machining of cassette cover:

Actual cassette itself is relatively straightforward casting, could be made from solid billet. How pretty it would be depends on the skill of the machinist.

The cover however is fairly involved. Burton's have spend a bit of time making a new pattern for the front and back cover and there's not a lot of room to play with. Just bear in mind this is quite a big solution to a problem that has an off the shelf solution.

Regards

Gerry

[CBUEB1771]

The removable water pump assembly is also new, and appears to have a larger bearing assembly and cast impeller.

No problems whatsoever. I gathered all the bits of my Bean kit together today. I was wrong in one area, my Bean kit definitely has a non-standard bearing cartridge, much larger than standard. I do recall now that they were using something like an an Esprit bearing. My Bean-kit front cover is obviously an original TC piece, heavily welded up and re-machined. I bought my Bean kit in December 2006, after they put me off for more than a year, so I didn't think it was too far out of date, but it sounds as if they have a totally new kit. Whatever, my Burton kit is the bee's knees and that it what I will put into my new long stroke engine.

[kstrutt11]

Intresting comments,


My logic behind using the std bearing was thay I will always be able to get them as they are a standard Lotus part availble from many sources, Burton may go bust or decide not to suupport twin cam and overnight the parts source has gone...
Also the last one has been in the car for 14 years / 30,000 miles so it should not need to be to regular a task.

The basic design is to use the original sealing ring that goes behind the impelor at the backof the front cover but machine the centre out to the diameter on the impellor such that it will slide through it

My design uses a cassette which is very similar to the Burton one and fits inside the sealing ring above with a o ring around the periphory this should be pretty easy to machine. For the front cover I plan to machine a flat surface aprox 8mm wide on the existing front face and seal it to the cassette with a o ring (groove machined in face of cassette) The only place metal needs to be added is to one of the bolt posts (to make all 3 the same height) and here I will use a shim instead as I don't want to risk distortion etc.

I will do it all on my lathe and mill, the only area which should need some hand work are the 3 slots in the cassette for the water to pass through, as I don't have a rotary table these will have to be finished with a file. I reckon it will take between 10 and 20 hours but as I enjoy hands on work such as this I don't see it as a cost more cheap entertainment!

The good news is it seems to have stopped leaking after using it so hopefully as I don't plan any journeys of more than 15-20 miles for the rest of this year I can live with it until the originaly planned winter freshen up.

When I start I will post progress on the pump.

Kevin

[rgh0]

Kevin
I have an new racing engine build I am working on currently which has a modified original front cover and locally made cartridge unit machined from billet. I am away for the next couple of days but i was going to pull the cartridge this weekend for a seal replacement. I will take some photos and post. The cartridge uses a larger bearing that I believe was used on the later ford kent engines. This larger bearing can also be retrofitted into the standard front cover by boring it out.

The cover needs to be in good condition with little corrosion or you break through into the suction water passge when you machine the flat front surface for the cartridge to mount on.

regards
Rohan

[Lincoln62]

I put a new kit in my pump 14 years (and 25000 miles) ago when I rebuilt the engine. I had thought about a cassette or an electric pump when they became available but the standard pump is going fine. If I only have to replace it every 15 years I will be happy. I am careful no to overtighten the belt and replace the coolant regularly.

After 15 years it will be worth taking the head off to check it over anyway, the rotten fuel we have these days is sure to be clogging it up.

Pete
66S2

[scottlong1]

I made my own cassette about 7 yrs ago, used the stock rebuild kit. The difference from your description of sealing it is I put the seal for the cassette to front cover on the casettes diameter instead of the flange face. When I had measured everything up it would have broken through the casting if I fully machined the front face. I machined the face of the cover just enough to get the 3 bolted areas sitting on a flat face. I also had to relieve the flange a bit over the lower water passage bulge I think. I went with the original bearing etc as over here I don't know of any common water pump that comes without a casting attached.

Scott

[kstrutt11]

Yes my descrption wasn't very good, thats exactly what I planned, machine the grove in the face of the cassette.