I am working on my Tan 1967 Land Rover Station Wagon 109. Alex from British Motor in Sacramento CA USA is reviewing the Motor and setting tappets for me. He calls ask why due you have a Rev Limit Rotor set to 2700 rpm = 5400 cam rpm max
I bought a 1971 Triumph a few years ago and that had a rev limiter rotor which shorted out the spark at its maximum setting. On the motorway, this limited the speed to 74 MPH. As the motorway speed limit in the UK is 70 MPH, I assumed that it was intended to keep the car at or near the
70 MPH speed limit without the driver having to constantly check the speedometer. It wasn't a standard option, but an after-market modification.
Yours might be similarly set to keep to a legal speed. Have you checked what speed it limits you to?
For the record, I found the rev limiter a confounded nuisance in the lower gears, so I swapped mine out for a standard rotor arm and I now watch the speedometer.
Think what happens is the rotor is centrifugal and moves to the point where it is no longer pointing at the correct cylinder. But is a pretty crude device causing a misfire. Not something you'd want to use as a sort of cruise control. Because on a carb engine fuel is still being drawn in, when it sparks again you can get a backfire.
Only vehicle I remember it being fitted to was the Lotus Cortina.
I once owned a IOE Rover 105. The red line for that was 4750 RPM I believe the 3-Litre P5 had a higher rev limit, but I agree with you that 5400 RPM would be really pushing it.
I am pretty sure that mine was centrifugal but I don't think it pointed to the wrong cylinder, it shorted the coil input to the rotating spindle and therefore prevented the spark. I can't prove it now though.
Yes- that would work too. I can't say I've ever seen one. It does seem a crude device to make reasonably accurate, though. Did it have some form of over centre so it went quickly from 'go' to 'stop'?
I do remember it not being subtle on the Lotus Cortina I had a drive of. ;-)
On one side was the usual hook shaped wiper that carried the spark to the spark plug terminals. Opposite was a weight inside a shroud that was spring loaded and centrifugal force on that weight shut off the spark.[1] The weight had three tapped holes and a small bolt that went into any of them. By having the bolt at adjustable distances from the centre it was possible to set different rev limits for the cut-off. When I bought the car, it was in the middle hole, and I discovered the rev limiter effect during the 200 mile journey driving from where I bought the car to my home. I didn't try the faster and slower settings afterwards because the concept of limiting the engine speed in the lower gears made no sense at all, and I just changed it for a standard rotor arm.
[1] I could feel the spring and it was quite a strong one, but I never checked whether it was an over-centre arrangement.
I think the 45D is a 4-cylinder distributor, yet some of the 109 models were available with a 6-cylinder engine.
If you go to ebay.com and look up Land Rover 109 and specify either 2.3 (4-cyl, I believe) or 2.6 (6-cylinder, I believe) [I haven't owned a Rover since 1976 so my memory is a bit hazy now; you need to check my assumptions], then you should find an appropriate rotor arm. It might come from the UK, but ebay looks after overseas orders OK, and you will probably get change out of $10 plus postage. You might even be lucky and find a US supplier which is likely to be cheaper.
Your existing rev limiter version should keep you mobile until the replacement arrives.
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