Cut out rotor
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I remember the original cut out rotor as being fairly effective in consistently limiting RPM?s to 6500. Is anybody still using these rotors?
Thanks
Chris
Thanks
Chris
67 Elan Super Safety
67 Elan +2
67 Elan +2
- seniorchristo
- Fourth Gear
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- Joined: 19 Dec 2013
While these were the hot ticket "in the day", I wouldn't trust a motor I cared about to a 50 year old part that was likely not all that consistent to begin with. Worse yet, you may get a repro part where the weight and spring strength may or may not yield a correct cut out rpm. How would you know until it's too late? There are many modern and reliable rev limiters available these days, most being adjustable to any desired rpm, and with "soft cut" technology to boot.
This is my current favorite as it mounts on a standard coil and isn't too obtrusive.
Others will likely have their favorites as well, or may weigh in and say the factory centrifugal rotor is just fine!
This is my current favorite as it mounts on a standard coil and isn't too obtrusive.
Others will likely have their favorites as well, or may weigh in and say the factory centrifugal rotor is just fine!
Steve
Elan S1 1963-Bourne bodied
Elan S3 1967 FHC pre airflow
Formerly:
Elan S1 1964
Elan S3 1966 FHC pre airflow
Elan S3 1967 FHC airflow
Elan S4 1969 FHC
Europa S2 1970
Esprit S2 1979
Elan S1 1963-Bourne bodied
Elan S3 1967 FHC pre airflow
Formerly:
Elan S1 1964
Elan S3 1966 FHC pre airflow
Elan S3 1967 FHC airflow
Elan S4 1969 FHC
Europa S2 1970
Esprit S2 1979
- bitsobrits
- Third Gear
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Imho when you start to wind up the revs you watch the tacho with a 50 year old Engine.
Just for info the big valve is 6750 rpm
Alan
Just for info the big valve is 6750 rpm
Alan
Alan.b Brittany 1972 elan sprint fhc Lagoon Blue 0460E
- alan.barker
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The rev limiter was installed as standard on all twin cams originally - 6500 rpm in the standard and S/E engines and 6750 rpm in the later sprint engines. if regularly used at above 7000 rpm the standard cranks break so the continued use of a rev limiter either the original type with a cut out rotor or a modern electronic limiter is strongly advised
cheers
Rohan
cheers
Rohan
-
rgh0 - Coveted Fifth Gear
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Yes Jon - the limiting rotor arm is a full disc with a spring loaded weight that moves out to break the circuit.
Obviously springs can weaken reduced break rpm or the screw in additional weights could have been removed to increase rpm.
Given all this and normal erosion of the spark electrode theres no way I'd re-use the one i took out after a 30 year lay up.
Modern soft rev limited are the way to go.
https://images.app.goo.gl/w1gDdAaVC4o7wDud6
Obviously springs can weaken reduced break rpm or the screw in additional weights could have been removed to increase rpm.
Given all this and normal erosion of the spark electrode theres no way I'd re-use the one i took out after a 30 year lay up.
Modern soft rev limited are the way to go.
https://images.app.goo.gl/w1gDdAaVC4o7wDud6
- MarkDa
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A seller on eBay found a stash of the standard limiter rotor arms some years ago and one of our members here spotted his advert (which was not for Twink cars). A number of us members hastily bought some and the vendor reaslised they suited the Elan and put his price up.
I think they were actually originally for a Land Rover. Anyway the limiting rev is engraved on the brass bit (in distributor RPM, hence half the engine RPM).
New Old Stock is fine if you can find them.
There is a topic about this on the forum somewhere but I haven't yet refound it.
I think they were actually originally for a Land Rover. Anyway the limiting rev is engraved on the brass bit (in distributor RPM, hence half the engine RPM).
New Old Stock is fine if you can find them.
There is a topic about this on the forum somewhere but I haven't yet refound it.
Bill Williams
36/6725 S3 Coupe OGU108E Yellow over Black.
36/6725 S3 Coupe OGU108E Yellow over Black.
- billwill
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Here's one of the former topics, but not the original one.
viewtopic.php?t=40404&p=282044
and another, but still not the one I meant above.
viewtopic.php?f=38&t=20756
viewtopic.php?t=40404&p=282044
and another, but still not the one I meant above.
viewtopic.php?f=38&t=20756
Bill Williams
36/6725 S3 Coupe OGU108E Yellow over Black.
36/6725 S3 Coupe OGU108E Yellow over Black.
- billwill
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MarkDa wrote:Yes Jon - the limiting rotor arm is a full disc with a spring loaded weight that moves out to break the circuit.
Obviously springs can weaken reduced break rpm or the screw in additional weights could have been removed to increase rpm.
Given all this and normal erosion of the spark electrode theres no way I'd re-use the one i took out after a 30 year lay up.
Modern soft rev limited are the way to go.
https://images.app.goo.gl/w1gDdAaVC4o7wDud6
Well I definitely do not have one of those in my distributor. Engine was rebuilt by QED in 1992 and seems to have done 50,000 miles since. It's very strong and seems to like a good thrashing, but it only takes one part to let go at speed.. The soft limiters look good but at 25% the price of a 123 distributor, maybe I'll save for one of those.
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JonB - Coveted Fifth Gear
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