Anyone experienced this? - Rev limiting rotor

[Wiese]

Hi:

I just replaced the distributor cap and rotor on my '73.5. It has a '75 2.7S motor installed. The rotor I installed is Pelican Parts - Product Information: 911-602-928-00-M47 which has a rev limit of 6500 and is specifically made for the '74-'77 2.7l engines.

On the first test drive the car ran fine, however, the rev limiter shut of the ignition (hard) at around 5600-5700 rpm. So this makes for a great rotor to swap in before valet parking, but it is not good for my daily driving.

Any help or ideas would be appreciated! Thanks.

[brazen]

I see the big "6500" on the picture, but I also managed to nab this from the notes section:

Originally Posted by PelicanParts

Worried about your lead-footed friend over-revving your engine when you let him test drive your 914? There are two types of rotors available, one with a rev limiter, and one without. The rev limiter has a limit of 5800 RPM, and protects your engine from overzealous drivers. A small floating weight on the rotor grounds out the coil at the RPM limit preventing valve train and other engine damage. A very worth upgrade for your engine. Shipped as stock equipment until 1975.

Guess it works as advertised? Which is to say, a bit too cautious..

[Wiese]

Hi Brazen:

Thanks for that information, however, the part number for the 914 distributor rotor is different, and yes, it comes with a 5850 rev limit (Pelican Parts - Product Information: 022-905-225A-M47).

My rotor was delivered with the correct 911 part number on the box and the 6500 sticker on the side, but I suspect that it may have been mislabelled and I really received a 914 rotor!

Kay

[brazen]

Although the quoted notes I included mention the 914, I cut and pasted that from the 911-...-M47 rotor parts page. I haven't got any hands on experience, but would a 4-cyl rotor even fit the 6-cyl distributor?

Since yours is labelled 6500 and came in a 911 box, I'd go about contacting Pelican to see what they say. Best of luck to you, a car with no guts is no fun!

[Jerome74911S]

I hit the 6500 rev limiter on my '75 engined car and it cut off the ignition at 6500 rpm, as advertised. Either your limiter is wrong, or the tach is.

I find that the tach needle has some inertia to it and I don't trust its accuracy, especially as it swings around rapidly while revving through lower gears.

Do you have any power above 5800 rpm anyway? That's where max hp is produced.

[maui44]

+1 Jorome

Hook up a meter to see what it shows as the RPM. If it matches the Car Tach. then you may have a defective rotor. Is there a part number on the part?

[Wiese]

Thanks for all the feedback guys. My tach is pretty accurate according to external timing meter. Even without looking at the tach, I could tell that something is wrong as it cuts off way before my normal shift point.

I was running a non-limited rotor before, but thought a 6500 rpm limiter is good insurance. However, this one literally chokes the car.

[moneymanager]

Just tear the top of the rotor off (the spring and the little sliding piece) and be sure to shift at the right place.

[analogmike]

The cutoff RPM can be adjusted easily by bending the metal arm which holds the end of the spring. it's on the opposite end of the contacts. Maybe not enough for you, but easily a few hundred RPM.

[tobluforu]

This is a greatt thread, shows all the rotors, non rev, etc that one can buy, with part numbers.
Ignition Rotor Meltdown

[john walker's workshop]

usually there is an RPM # on the bottom of the rotor. used to be anyway.

[Wiese]

Update:

Checked the rotor (it's a Beru) and there is only a sticker saying "6500". My old rotor was a Bosch and had "7100" on it, but the PO broke off the slider/spring, so it is essentially without a limit. I cleaned up the old rotor and with fine sand paper sanded the contact points and popped it back in.

I also used this occasion to check how tight the wires are in the caps at the distributor cap and 3 were so loose that they fell out as soon as I pulled on them. I have the Bosch ignition wire set so they have a "wood screw" to screw them back onto the wire.

Car runs like a champ again and happily revs to redline.

[Wiese]

Thanks, that is a great thread. And you can't beat $3.99 for a simple rotor!

Originally Posted by tobluforu

This is a greatt thread, shows all the rotors, non rev, etc that one can buy, with part numbers.
Ignition Rotor Meltdown

[john walker's workshop]

Checked the rotor (it's a Beru) and there is only a sticker saying "6500".

made in east wambango now.