Lotus tips page 3

Lotus tips page 3

In November 2003, the Valeo alternator in my 1988 Esprit died for the third time, with a hair under 90,000 miles on the car. Due to the ground work that several turboesprit list members (A tip of the proverbial hat here to Phil Harbison, Tony Grasso, and Eric Fournier) did, I decided to go with the substitute Bosch alternator this time. The Bosch number is AL49X and it is found on the following BMW's: E30...'86-'91, E24...'86-?, E23...'96-'97, and E28...'86-'88 (not M series cars). It's also used on some Audi vehicles, but the AL49X number should be able to get you the correct unit, it was the number that my local Bosch dealer used. Mine came with papers in the box that claimed that the Valeo and Bosch are interchangeable, and how either one (Bosch or Valeo) could be in the box. They are VERY similar, but there are a few minor differences.
At Autozone, the number is Duralast 14789.

According to Esprit Guru and Fellow Lotus Corps member Sanj: "the Valeo was used '83-'95.5 in the US. The '88-'92 book indicates a different 70A alternator was used on normally aspirated cars, but all others are listed as the same 90A part. Before '83 I have no info".

If the alternator in your Esprit is giving you some problems, and if it's a Valeo product it will give you problems... it's only a matter of time, I suggest you consider following the recommendations here...... and DUMP the Valeo! According to one of the other people that has done this substitution, the Bosch unit produces more current and charges the battery even at low idle speeds

The Bosch unit is slightly bigger in diameter than the Valeo, but not enough to cause a problem. I had to struggle a bit more than usual to squeeze it into it's place under the plenum. Since my car is Bosch injected, there is a bit more in the way than 1989 and up cars. The pivot bolt mount was virtually identical to the Valeo, however the adjusting bolt mount on the Bosch casing is considerably deeper requiring a MUCH longer bolt. I think I went with a 3.5" or 4" long bolt to give the nylock nut some threads to grab on. I may in future try and adapt the old special Lotus adjuster bolt to work with the Bosch. That special head sure made it easier to lock the position of the alternator. The distance from the centers of the two mounting bolt locations is a tiny bit further apart on the Bosch and again, shouldn't cause a problem.

The old pulley swapped, also with no problem. I did have to slightly massage the inner diameter of the collar under the pulley nut to get it to fit the shaft on the Bosch unit. In order to get the pulley set up in the right location so the belt will track properly, I only used one of the washers that was used on the Valeo unit under the fan and pulley under the fan on the Bosch unit when I switched them over. The other 'keyed' washer that was under the pulley on the Valeo, I put between the pulley and nut on the Bosch. You might want to measure the pulley position on your Valeo alternator to insure that you get it set up right on the Bosch.

The only thing that might be scary to some was removing the four long screws holding the casing halves together to rotate the back half 180 degrees. If you don't feel comfortable doing this yourself, any mechanic can do it for you easily. This rotation puts the wire terminals in a position similar to the original Valeo unit. In my case, the smaller alternator wire had been hooked to the Valeo using a spade terminal. To hook that wire to the Bosch, I had to solder a ring terminal to the wire, and get an 5mm .80 pitch (metric) nut to secure it.

Since doing this conversion, another alternative has been suggested by Yahoo turboesprit lister Guy, his suggestion follows:

I used the 86-88 VW SCIROCCO alternator
The installation is slightly easier than the BMW Bosch that is common. The case bolts don't have to be cut and the back half doesn't have to be rotated. The adjusting ear is thin like the valeo but it is tapped (M8). You can either drill it out and use the stock bolt or put a bolt in from the back side and put a nut on the front. I put the bolt in from the back. It's easier to get it in but more difficult to tighten. The key and retaining collar get modified per his (mine previously mentioned on this page) instructions.
good luck regards
Guy 90se

Check out the pictures below from my Valeo to Bosch conversion and see for yourself:

The Valeo unit from the front after the fan and pulley have been removed.

The Valeo from the rear. Note the 2 electrical terminals, one of which is a spade terminal.

The Valeo from the side, note the 'ear' on the bottom of the photo. This is where the adjustment bolt goes and is different on the Bosch unit.

The Bosch unit from the front with the original Valeo/Lotus fan and pulley installed. It would be mounted in the car in this position

The Bosch unit from the rear. You can see the 2 electrical terminals, both of which require a nut. You can reuse the original Valeo one on the large terminal (B+), but will need a 5mm .80 pitch metric nut for the other terminal.

The Bosch from the side, see how the 'ear' at the bottom of the photo differs from the 'ear' on the original Valeo unit. This is not a problem, it just takes a longer bolt.

This is pretty much all you can see of the Bosch alternator on a Bosch injected Lotus Esprit. I took this picture before putting the air filter and air box back in. Notice the aluminum alternator adjustment brace... I replaced the cr*ppy original Lotus plastic brace shortly after buying the car in 1990. It cost me $20 and gave me a whole lot of piece of mind not having to worry about the plastic one breaking.

Due to circumstances you can read about here I had to disassemble my Esprit late in 2004. Some tips can be found here too.

In this picture, you can see my engine upside down on the engine stand. Originally, I had it bolted to the bolt holes marked with white arrows. Found out though that these 2 holes can not be used as they are in the 'girdle' that holds the crankshaft bearings, which holds the crankshaft in place. No way to get the crankshaft out if you use these marked holes. Instead, use the holes used in this image. You will have to use three 9/16" washers as pictured up against the block to prevent damage to the 'dowel bushings' in the block.
Use 1 - 10mm bolt, 1.5 pitch, approximately 3" long.

The bolt and hole marked with white in this picture is the one you can use any bolt and nut with as there are no threads in this location. The bolt I used here was 3.5" long. Notice that in order to maintain proper spacing 3 washers were used here as well.

Here I used two - 10mm bolts, 1.5 pitch along with 3 washers in each location, for reasons mentioned previously. These bolts were nearly 3" long. Sorry, but I forgot to write the metric length. Now, I will be able to remove my crankshaft so that the pilot bearing pocket can be machined to accept the better quality Renault pilot bearing.

I went to the Palisades Park in Savannah, Illinois with my local British Car club group. I was approximately a 50 mile drive, but as we pulled into the park, I could tell from the feel of my shifter that something was wrong..... it just flopped around and all I could access was 3rd and 4th gear! Got it home and took the interior apart. Details in the next column. From the looks of it, there is a pin or bolt missing from the shifter. The parts manual does not give a clear view of this part, so I'm only guessing as to what goes in there. Judge for yourself from the image:

I took the shifter to a hardware store with me. Found that a 12mm bolt was a perfect fit through the bore of the shifter and linkage. Bought a 12mm x 75 x 1.75 thread and a nylock nut. A bolt that long made sure that the smooth shank was what the shifter parts pivoted on rather than bolt threads. I "Dremeled" the bolt to a shorter length, left it long enough to get fully through the nylock insert and then some (but barely). I also ground the head of the bolt thinner as I could tell it might hit the chassis or the shift mechanism if I didn't. For clearance issues during shifting it was also important to stick the bolt through from the rear to the front. Tightened it up, reassembled the car... good as new... for only about $3.50! Sure beats the price tag on my last repair.

The level of interior disassembly is pretty clear when you look at this photo.

You have to unbolt the instrument binnacle (4 bolts), unbolt the radio surround (2 wing nuts WAY under the dash, and 2 phillips head screws (hidden under the console), remove all 4 of the a/c and heater controls, remove the heater control face plate (2 screws), remove the console (2 screws), lift off the console, unclip the leather shift boot, remove the shift knob, lift off the console, remove the 4 screws holding the rubber shift boot retaining ring, remove that ring and the rubber shift boot, remove the 6 screws holding down the shifter recess cover plate and then remove the cover plate. Move the crossgate lever out of the way by removing the hold down bolt, and pivoting it out of the way.... being cautious not to loose the spacer washer under it. Remove the 4 bolts holding the assembly down, but be advised that there is a spacer washer under each corner.

So, my Ford Ranger pick up got a flat tire. Rather than mess with getting the spare out from under the bed of the truck for only a couple of hours, I decided to transport the tire the not quite 1 mile to the local Goodyear for repair in the boot of my Esprit! The first step was to remove the wing, a step that Atwell would certainly approve of. Gently put the tire in there, but it was so big, the hatch wouldn't close, so I bungee corded it into the partially closed position. Guess these pictures will prove that owning a Lotus is not necessarily an impractical decision!

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