Think I have stuffed my alternator. What kind do people have. I guess easiest way is to remove the one that's there and have a look but thought I would ask first.
Mine is mounted at the lower left of the engine as you look at it from the driver's seat.

 

You have an alternator? All the S Type's came from the factory with a generator, so if you have an alternator then it has been retrofitted.

Assuming it is factory original, the first things to look at are the belt tension, as the tensioner can get weak with time, and then the dynamo control box may need adjustment or replacing. They have points in side that may be burnt.

 

Most people use the Dynalite units ~ they have a few Jag models depending on output you want. They use them because they are purposely built to look like a Lucas generator & are available with the PS Pump offtake on the rear. (Also known as Dynamator in the US.) Available positive & negative earth. Also available without PS Pump offtake.

Alternators are not cheap. You may want to have your existing unit rebuilt. Might only need new diodes.


https://www.powerlite-units.com/dyna...ns.html?page=3





















Standard Lucas generator on a friends car (There was an uprated unit available with a brush cover band around it similar to above) IIRC Standard 30amp ~ uprated 45amp.

 

I changed to a Dynalite a couple of years ago when I converted to Negative earth. The unit looks identical to the original Generator, easy to fit and gives a lot more power. Prices were up around £600 in 2014 but dropped to around £150 when I came to buy one in 2018. This is one site that sells them but they have gone back up in price. https://www.powerlite-units.com/dynalites/rac007.html

 

Another alternative is the PowerGen, it's cheaper and puts out 90 amps!

Link

 

Does the Lucas/Jaguar twin gang pulley fit on their shaft?

 

these conversions seem to be the future of the old generators.

in the US, the company GENER-NATOR claims they invented the conversion. They cannot do the ones for Jaguar with power steering pump, but they convert the Lucas generators, the C45 preferably.
https://www.gener-nator.com/default.htm

What I have heard is that the heat buildup inside the constricted generator case causes these conversion units to fail early, not to mention they only produce around 30 amps.
I have only heard this, I have no experience with these things.

but Retro-Air in Dallas Texas sells an actual alternator conversion for XK engines with power steering pumps.
I prefer that one because it is an actual 70 amp alternator that comes with all neccesary mounting hardware and wiring and it is more serviceble locally by alternator shops. The RB340 Voltage Regulator is bypassed, not used with this alternator, since the alternator has its own regulator. Owners leave the RB340 in place for looks or just remove it.

https://retroair.com/jaguarairconditioning/dynamotoalternatorkits.html

for the cost, the Retro-Air unit is the better buy if your car has power steering or if it doesn't.

I find the ones in the UK and Gener-Nator way too expensive.

 

Close but no cigar! The Lucas shaft is 15mm and Ford/GM is .64" or 16.25 mm so you would either have to use a spacer or buy one of their pulleys.

Link

 

Actually 40 amps Jose. No known problems with overheating and a lifetime guarantee.

 

Is there an alternative to the power steering pump driven from the rear of the dynamo/alternator? So could you fit a modern alternator, not a 'period' looking one and use an electric power steering pump to drive the standard s type power steering box?

 

I did a lot of looking into this, and the easiest alternative is to put in a 4.2 that has extra mounting bosses on the block and bolt in an XJ6 style steering pump and alternator.

Electric steering pumps take a lot of power - in the order of 80-90 amps, and then you need to fit a steering angle sensor and ECU so that the pump is only driven when you are turning the steering wheel, as you don't need assist when the steering isn't moving. I did consider this possibility but it's not simple.

 

Have a look at the set up of the Jaguar 420 steering pump. They had the same PAS Adwest Variomatic as the later S Types but they had a pump mounted near the distributor which ran off the auxiliary belt. Not sure if the size of the 420s engine bay was larger than the S type but I know it would be difficult to fit one to an S Type because of the lack of space. Everything is doable there are just varying degrees of difficulty.

 

The 420 has extra bosses on the block to bolt the brackets to though, the 3.8 doesn't have those.

I did a DIY solution. I started with the alternator for a diesel Vauhaull Corsa, then removed the vacuum pump and machined an adpater plate and then a coupling between the PS pump and the alternator shaft. It fits on the original dynamo mounting bracket and the alternator puts out 90 amps. So far it has worked very well.

 

1) BTW ~ the 420 pump is a Saginaw unit delivering 1200psi.

2) Dynalite will even sell you a RB340 Voltage Regulator look alike empty box to keep your engine compartment looking original.

 

I know that alternator would be hard to find here anyway, but for clarity- are you still using the 2rib belt? And did that alternator have something on it's rear in it's "stock" vehicle? Very ingenious.

 

There have been a number of different alternator conversion kits from XKS Unlim/Moss. SC Parts, MC Wilkinson etc that accommodate the Hobourn Eaton roller pump with both single & twin ribbed belt pulley configurations available if original look is not important to you.


XKS/Moss unit. They also sell Dynalite.



https://xks.com/i-7150766-jaguar-alt...%26go%3DSearch

 

Yes, I'm using the Jaguar 2 rib belt. The pulley is from a Series 1 4.2 E Type alternator. The shaft is slightly bigger than the hole in the pulley, so I needed to open up the pulley hole. I removed the spring loaded tensioner as I couldn't get enough tension on it and instead use the alternator as the moving member to tension the belt. I had to get a different top link that was longer, but I simply looked around the junkyard until I found something suitable. I think the one I have came from an early 80's Ford truck.

I bought the alternator off Amazon UK, they shipped to Canada no problem from the UK. Yes, the original application had a vacuum pump on the back of the alternator as it was a turbo diesel. So it had a nice long through shaft that was splined. I machined a coupler that fit into the PS pump and the other end had the spline of the alternator shaft so it just slides together.

 

Had my alternator tested and it is ok so need to track down reason the ignition light stays on permanently. This started after i fitted another indicator unit. BTW the unit i have is a Bosch U-K1 55A and was fitted to holdens here in Aus which means its easily replaceable but only 55A