Lineup of 3 Land Rovers

Groenie, Spikkels, White LR

I don't drive a Land-Rover because it's a 4x4. I drive a Land-Rover because it's a way of life.

Driving a Land-Rover is fun. Don't believe me, read this posting from the Land Rover Owner Mailing List. (This should also give you an idea of my definition of 'fun' :-)


Main  --  Spikkels  --  Groenie  --  CY7545  --  Jabba  --  Tech  --  Trips  --  Tips  --  Recipes

Tips, tricks, and general stuff that might be useful to you


Scope

I know a bit about Series I, II, IIA and III Land-Rovers. Anything newer than that is not retro enough :-)

The info here is based on the Land-Rovers I own / have owned / drive on a daily base. Which are: a 1955 Series I, a 1959 Series II, a 1963 Series IIA Forward Control, and a 1965-ish Series IIA.

Mechanically, the SII is much the same as the SI that preceded it. The body changed, to the shape that most people are familiar with. But the SII axles and gearbox are Series I components. The SII came with a 2 1/4 engine that is almost but not quite the same as the 2 1/4 everyone is familiar with. When the SIIA got the 2 1/4 diesel engine, the 2 1/4 petrol engine was upgraded to the same size main bearings as the diesel. Which makes the standard 2 1/4 petrol engine nice and strong. But of course it also made an orphan of the SII 2 1/4, which was only available in 1959 and 1960. The bearings for this engine is difficult if not impossible to find.

The SIIA got the upgraded gearbox, with the thicker layshaft. And the front axle changed, the steering arms are attached to the bottom of the casings (non-pendant, they call it).

Somewhere close to the end of SIIA production, the wheel nuts changed to UNF (from BSF). SIII wheel nuts are UNF. And the SIII got a new gearbox, with syncro on all four gears. Also, the hydraulic clutch and release bearing mechanism on the SIII is different, I don't know why they changed it.


Conversions

1 HP = 0.746 kW    1 kW = 1.341 HP
1 lb.ft = 1.35 Nm  1 Nm = 0.741 lb.ft

1 gallon (British) = 1.2 gallon (US) = 4.54 l
1 Bar = 100 kPa = 15 psi, give-or-take.
 


December 2003

Series LR bellhousings

If you phone Gilo Engineering (In South Africa, YMMV) and ask for an adaptor plate, they'll ask "4 cylinder or 6 cylinder?".

The Series One, Two and Three bellhousing have 12 holes, spaced at give-or-take 30 degrees (it may, of course, be exactly 30 degrees, this is not important).

For the 4 cylinder 2 1/4 engine, there's a stud at 12 o'clock.

For the 6 cylinder 2.6 engine, the studs are moved give-or-take 15 degrees, so there is no stud / hole at 12 o'clock.

The Series I 4 cylinder (2 litre) engine has the same configuration as the 6 cylinder, it's the same design (semi-side valve, beautiful engine, but I digress).


Dual Battery setup

There are many schemes for charging two batteries from one alternator. I use a manual one, a relay powered from the switch on the SII dashboard, which I turn on to charge the fridge battery. Similar to Johann Hugo's schematic which you will find under "Homemade Equipment" on www.overland.co.za (direct link here).

But then the idea hit me. I'm carrying a spare alternator in any case, ever since I lost an alternator in Zambia. Why not mount said alternator on the engine permanently and use that to charge the fridge battery? Less strain on the primary alternator, complete isolation without voltage drops, and I will need some simple bridging box to fix things if one of the alternators pops. This will of course fall back to the scheme I'm using at the moment.

I'll probably implement this in the Forward Control.


Rim Offset

SAE specifies that a positive rim offset narrows the track. Yes, this is strange. There's a whole writeup archived on the DeTomaso list. Anyway, inset is positive offset, outset is negative offset, and the center line is half of the rim width. Which is measured between the rim flanges, on the tire (in) side.

This table comes from the LRO mailing list. I've changed the table headings to be in line with what I've said above.

  Rim Width Distance from
outboard bead to
mounting face
Distance from
inboard bead to
mounting face
Offset from
centre line
(inwards)
SWB

5"

0.75"

4.25"

1.75"

LWB early

5.5"

0.75"

4.75"

2"

LWB late

5.5"

1.25"

4.25"

1.5"

LWB split

5.5"

1.375"

4.125"

1.375"

FC early (SIIA)

6.5"

2.75"

3.75"

0.5"

FC late (SIIB)

6.5"

3.25"

3.25"

0"

On the other tentacle, my SII & IIA parts catalogue (605957) gives

Part #

Use

Description

231601

88, Except NADA

Road wheel, well base rim type

526753

88, NADA

Road wheel, 6L x 15"

272309

109, offset from rim centre line 1 13/16" (1.8125")

Road wheel, well base rim type, 5.5" x 16"

568966

109, offset from rim centre line 1 5/16" (1.3125")

Road wheel, well base rim type, 5.5" x 16"

217267

Optional on 88 models

Road wheel, detachable rim type

526753

Optional

Road wheel for sand tyre


January 2004

Setting your timing, and notes on centrifugal and vacuum advance

Distributors wear, just like any other moving part of your engine. If you're checking the timing with your timing light, and the little mark is not dead steady at idle, you probably have a worn dizzy.

Take off the distributor cap and rotor and give the shaft a wiggle. Does it move side-to-side? New bushings required. Up-and-down motion is bad too -- the driving gear wants to climb out and that causes a wandering timing (exception is when the driving gear is retained by some other means, and the distributor slots into that. Or when the distributor is driven from the camshaft. But in general, any movement is bad.)

Remove the points carrier plate. What's the pivots for the weights look like? Probably needs to be replaced.

With the engine running and the vacuum pipe plugged at the carburettor, slowly increase the revs while watching the timing mark. It should advance slowly, and return to the original setting when you drop the revs to idle. It should also advance by the same amount every time you do this. If not, your weights are sticking.

If you're near Cape Town, take the dizzy to Gary (082 962 5677) in Capri Village (Near Fish Hoek). He does a great reconditioning job.

OK, now to actually set the timing. The manual will tell you to line up some mark with some pointer. Sure, when the engine was new, those marks were accurate. But maybe the pointer is bent. Or you have a different pulley with the mark in a different place (case in point, VW 1700 has different timing marks for carburettor and fuel injection models). And, if you changed the cam, the optimum timing point probably changed too.

So, hook up a vacuum gauge. No, not to the vacuum advance line, that's ported vacuum and not what you want. Use the line going to the brake booster. You should have a vacuum gauge on the dashboard anyway :-)

Fiddle with the timing to maximize the vacuum reading. That's where the engine wants to run. I generally retard the timing to drop the vacuum a bit (5 - 10 kPa) but maybe I'm overly cautious...

Your mechanical advance should add about 25 degrees total, which should be "all in" by 2000 to 3000 rpm. But again, ask the engine. With the vacuum advance still disconnected, find a hill, floor the throttle, try to make the engine ping. If you can, you have too much advance. Either retard the dizzy (easy, but not optimal) or change the mechanical advance (stronger springs, this becomes a bit esoteric.)

Your vacuum advance should add about 20 degrees (because they tell me that a total advance of 55 degrees is good, but more isn't). You need a vacuum pump to test this. And test drive to ensure you're not adding too much advance. But with the stock dizzy and a mostly stock engine, you don't need to stress about this bit.

Just make sure you don't set the timing on the bleeding edge on a cold day, 'cause it's going to ping madly when it gets hot. Or when the fuel quality drops, out in the bush.

More about vacuum gauge readings & interpretations here.

Last note: If you break it, I don't want to know about it, and you get to keep all the pieces :-)


January 2004

Ramblings on Power and Torque

Engines are rated in terms of power (in kW) and torque (in Nm).

Torque measures the (twisting) force applied to something, be it a wheel or a bolt. It's defined in terms of a lever arm, if you apply a force of 1 Newton to a 1 metre long pipe clamped in a vice, you are applying one Nm to the vice.

Important point: You can apply a lot of torque without doing any work (lean back on your chair. That's it, torque on the chair, no work being done... :-)

Seriously, if you're undoing a bolt. You apply increasing torque until the bolt "breaks" loose. The torque you applied up to the point where the bolt loosened did not do any work.

Power is the rate of doing work. Running up a flight of stairs takes more power than walking up.

When it comes to engines, power and torque are related by the following formula :

 Torque x RPM
Power =
 

9549

Where power is in kW, torque is in Nm, and the 9549 is the result of using those units (for HP and ft.lb it's 5252).

Of course, we all want to increase the power and torque of our engines :-) A longer stroke gives more torque, but a long stroke engine is a low-revving engine (there's a limit on how fast the piston can move in the bore. And a long stroke means that it takes longer from the one end of the stroke to the other. Which is half a revolution). Long stroke engines are also less efficient (as far as I know, relatively "square" engines "square" : bore = stroke) are the most efficient).

Of course, to increase the power, you can also rev the engine higher. Which is what Formula One racers do. Higher revs = more wear = engine rebuild after each race.

As Robert Heinlein said, TANSTAAFL.


Alternators

Bosch Voltage Regulator

Just for fun, I reverse engineered the voltage regulator off a Bosch Alternator from a VW Golf. See my reverse engineering page for details.

Bosch codes

A typical Bosch alternator has a description code like

N1 > 14V 40/110A.
N1  : Size (G, K, N, T, size increases alphabetically)
>   : Alternator rotates clockwise
14V : Standard (they make 28V alternators too
40 : Output current at 1800 rpm (alternator RPM, not engine RPM) 110 : Output current at 6000 rpm.


Studs

Before installing a stud, countersink / bevel the edge of the stud holes to a depth of about 1mm. This acts as a stress relief at the surface of the casting and prevents the metal around the hole from being raised.

Essential for aliminium, still a good idea for steel or cast iron.

And the loctite won't work if the holes are oily or dirty -- I use carb cleaner to clean the holes and the studs before assembly.


Brakes

Q : Dear Dr R. Lover, the brakes on my Series II pull to the left sharply. It's at its worst first thing in the morning, and it seems to get better after a bit of a drive. But the next morning it's back, just as bad as before. I've managed to lock the left front wheel up solidly, which scares the shit out of me and everyone else on the road. Please help!

A : You have brake fluid on the shoes! Just a drop or two from a leaky brake cylinder is all that is needed.

Put the front axle on stands, and pull the drums, shoes and cylinders. Haul the whole mess off to CBS, get them to re-line the shoes, skim the drums if required, and stainless steel sleeve the cylinders. Get new rubbers from them. Reassembly is the reverse. Have Fun!

(signed) Dr. Rand Lover.


High Ratio Transfer Box conversion

This conversion works, as far as I can figure it out, because of a number of coincidences.

The first important thing is that early (Series I) transfer cases have a small shaft (28mm dia) carrying the intermediate gear. Later transfer cases have a large shaft (41mm dia).

The second important thing is that suffix "B" boxes have a 2.89 ratio low range, while suffix "C" boxes have a 2.35 ratio.

Xfer Box

The first coincidence comes in when you realise that you can swap the input (27 teeth) and output (31 teeth) gears around (same tooth pitch) if you move the intermediate gear to the right.

The second and most amazing coincidence is that the low-range output gear required to make this work is the gear from the suffix "C" box (36 teeth instead of 39).

Another maybe-coincidence is that, while the high range changes from 1.148 (31/27) to 0.871 (27/31), the low range changes from 2.347 ((44*36)/(27*25)) to 2.323 ((44*36)/(31*22)) (assuming you started with a "C" box) -- in other words high changes but low doesn't.

Of course the insides of the input and output gears are not the same. The input gear rides on splines, so you need a spare input gear that is machined off and inserted into the output gear to become the new input gear. The output gear is drilled out to fit around the output shaft.

Xfer Box

Number of teeth on gears
Suffix B
274431
 2239

Suffix C
274431
 2536

Clear as mud? Lemme know if you don't understand. Also let me know if I figured this out incorrectly (I haven't done this, understand?)

2005-12-20 : The topic came up on the LRO list again, read all about it. But note, there's at least one typo in this email!


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