Discussion:
1967 Land Rover with 2.6L Rover motor with a Weslake Head
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2***@gmail.com
2017-01-07 17:19:45 UTC
Permalink
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

Why would Lucas make this type of rotor?

Fire Pump?

Open to all feed back!

josh t
Indy Jess John
2017-01-07 18:55:57 UTC
Permalink
Post by 2***@gmail.com
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
Why would Lucas make this type of rotor?
Fire Pump?
Open to all feed back!
josh t
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.

Jim
Dave Plowman (News)
2017-01-08 00:30:40 UTC
Permalink
Post by Indy Jess John
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.
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.
--
*(on a baby-size shirt) "Party -- my crib -- two a.m

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.
Indy Jess John
2017-01-08 10:17:20 UTC
Permalink
Post by Dave Plowman (News)
Post by Indy Jess John
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.
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.
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.

Jim
Dave Plowman (News)
2017-01-08 11:44:00 UTC
Permalink
Post by Indy Jess John
Post by Dave Plowman (News)
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.
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.
;-)
--
*IF ONE SYNCHRONIZED SWIMMER DROWNS, DO THE REST DROWN TOO?

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.
2***@gmail.com
2017-01-08 13:31:41 UTC
Permalink
Post by Dave Plowman (News)
Post by Indy Jess John
Post by Dave Plowman (News)
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.
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.
;-)
--
*IF ONE SYNCHRONIZED SWIMMER DROWNS, DO THE REST DROWN TOO?
To e-mail, change noise into sound.
Thanks for all the feed.

Where would I purchase the proper rotor for this motor I think its is a Lucas45D.

Thanks

Josh T
Indy Jess John
2017-01-08 16:32:22 UTC
Permalink
Post by 2***@gmail.com
Post by Dave Plowman (News)
Post by Indy Jess John
Post by Dave Plowman (News)
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.
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.
;-)
--
*IF ONE SYNCHRONIZED SWIMMER DROWNS, DO THE REST DROWN TOO?
To e-mail, change noise into sound.
Thanks for all the feed.
Where would I purchase the proper rotor for this motor I think its is a Lucas45D.
Thanks
Josh T
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.

Let me know how you get on.

Jim

Indy Jess John
2017-01-08 13:40:29 UTC
Permalink
Post by Dave Plowman (News)
Post by Indy Jess John
Post by Dave Plowman (News)
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.
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.

Jim
Dave Plowman (News)
2017-01-08 00:24:38 UTC
Permalink
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
Why would Lucas make this type of rotor?
Fire Pump?
Open to all feed back!
I'd say there would be little point in revving that old IOE design over
5400 rpm - even if it could.
--
*To be intoxicated is to feel sophisticated, but not be able to say it.

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.
Indy Jess John
2017-01-08 10:13:39 UTC
Permalink
Post by Dave Plowman (News)
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
Why would Lucas make this type of rotor?
Fire Pump?
Open to all feed back!
I'd say there would be little point in revving that old IOE design over
5400 rpm - even if it could.
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.

Jim
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