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Rev Limiting distributor rotor
Posted: Mon Oct 18, 2021 7:19 pm
by jury
For example :
In a stock 2.2 engine......If there was a NON rev limiting rotor in a Magneti Marelli Distributor....Where would the rev limiting take place ?
Cheers
Chris
Re: Rev Limiting distributor rotor
Posted: Mon Oct 18, 2021 7:44 pm
by hot66
… I assume until either it can’t breathe any more air volume in or the valves float and
Re: Rev Limiting distributor rotor
Posted: Mon Oct 18, 2021 7:45 pm
by Gary71
…or it throws a rod…
Re: Rev Limiting distributor rotor
Posted: Mon Oct 18, 2021 7:47 pm
by hot66
Look forward to Chris trying it now to see what goes first
Re: Rev Limiting distributor rotor
Posted: Tue Oct 19, 2021 8:52 am
by Jonny Hart
jury wrote:For example :
In a stock 2.2 engine......If there was a NON rev limiting rotor in a Magneti Marelli Distributor....Where would the rev limiting take place ?
Cheers
Chris
Doubt there ever was a stock car sold without the rotor limiter.
In the twin plug race cars, the 8 pin CDI boxes had an adjustable limiter. That’s the only ‘non rotor’ limiter I’ve ever seen on early cars. (Apart from my boxes which have a built in electronic limiter).
Re: Rev Limiting distributor rotor
Posted: Tue Oct 19, 2021 7:46 pm
by Lightweight_911
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I'm fairly sure that the Marelli distributors used in the 2.0/2.2 911T models didn't have rev-limiting rotor arms ...
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Re: Rev Limiting distributor rotor
Posted: Tue Oct 19, 2021 8:08 pm
by Jonny Hart
^ Interesting. So that’s just the T models?
Re: Rev Limiting distributor rotor
Posted: Tue Oct 19, 2021 9:13 pm
by Nine One One
Lightweight_911 wrote:.
I'm fairly sure that the Marelli distributors used in the 2.0/2.2 911T models didn't have rev-limiting rotor arms ...
.
The originals did, but reproductions do not, the repo’s also do not have the resistor in them either, and need a 5k resistor fitted in line from the cap to the coil to protect the CDI unit. I think PartsKlassik are the only retailers to mention this for the repo units?
https://www.partsklassik.com/p-992-igni ... relli.aspx
Re: Rev Limiting distributor rotor
Posted: Tue Oct 19, 2021 9:39 pm
by Jonny Hart
^. The 5k resistor is mainly about noise suppression. There’s also 3k in each plug top and about 1k in a typical HT lead. Resistance in the HT path also slows the current delivery which may be slightly kinder to the CDI unit.
Anyhow, if you need a limiter and don’t have a limiting rotor, there’s a programmable limiter in our CDI+ units. Much kinder to the engine too.
Re: Rev Limiting distributor rotor
Posted: Mon Nov 01, 2021 11:05 pm
by jury
Thanks for the replies....Hmmmm, next steps to try and figure out the weird flat spot.
I have had the distributor tested and all is good, replaced advanced springs . Also the petronix currently fitted, is all good. Negative connection on Battery terminal was loose...new clamp fitted !
The MSD box has been sent back to them to bench test and a new coil has been ordered.
Will report back
Cheers
Chris