I also would like to install a Crane ignition system or a Pertronix ignition for my 4.5. Does anyone have any suggestions as to which way to go? I want more speed (low end) out of this car, top end is great I have had it at 95 with plenty of power left and the passing gear at 65 is truly amazing. Any input would be appreciated.

Randy Durrance was an expert in distributors and ignition systems and only sold Pertronix. He had some bad experiences with the Allison/Crane system and would not sell it. Sadly, Randy recently passed away and we will miss his contributions to this subject.

On the otherside of the ledger, I know many people that use the Crane system and are quite satisfied.

I use Pertronix and have had no issues whatsoever.

__________________
Regards,

Tom S.
1971 280SL Tunis Beige Metallic
1971 280SL Tobacco Brown (13K miles)
1970 280SL Deep Red
1994 E320 Cabriolet
1999 E320 Wagon 4Matic
2002 LX 470
1992 Land Cruiser

I installed the Pertronix model #1684 on my 1963 220SEb M127 engine. It was a very simple installation that I didn't even have to remove the distributor. I included the Pertronix high voltage coil and the engine runs like a fine watch. I did not re-attach the original points systems ceramic resistor that I have been advised I should. I'll just watch it and maybe do so later.

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hi i used pertronix ignition kit for my 110 fintail and it is easy to install, works great . One thing that decided me to install the pertronix is that it looks like it is still in point system ignition and keeps the original look of the engine .

Yes, Petronix supplies a rubber tubular grommet with the ket but it doesn't have a lip on it to help it stay in place. As a result I'll have to apply some silicone to fix it in place. If you look closely at the picture attachment in my previous thread, you can see the rubber grommet has slipped out of the distributor.

So, with the Pertronix, you retain your existing distributor, right? Does the new system interface with the old distributor in any way? Mine has visable signs of wear, and some oil leaks at the bottom. Obviously in bad shape. Does this eliminate the trigger points also? I have a 75 SL, but it has a 72/73 300SEL 4.5 engine.

Yes, the Pertronix module takes the place of your points and condensor in your old distributor. You just remove those and insert a 6 pointed hub over the distributor cam lobe and screw in the sensing module where the points were, hook up two wires to your coil and your done! Since the original distributor lubes were used to open and close the point gap, a worn shaft would affect the gap opening on that system. This is not a critical thing with the Pertronix as there are no touching parts and only relative positions. Also since it is not an infra-red light diode system, it isn't affected as much with dirt film or oil. Other than what I mentioned on my previous thread, that's all I know!

Thanks GB. I'm fighting an intermittent miss that I think might be the result of distributor problems. This is the first vehicle I've had in over fifteen years with points, so whether it fixes the miss or not I think just getting an electronic system will be worth the effort.

Dieseldiehard:

I put the Crane system on the '70 280SL a couple of years ago and also used their "hot" coil. Haven't had any problems with it.

I didn't notice any improvement in performance, but it sure is nice not to have to adjust the timing any more. I've used Crane's unit on all of my "spark" engines (except the Tacoma which has a very different system anyway).

Cheers,
Wes

I put a crane 3000 in my 280SE 4.5.
Took some time to get it dialed in
(my distributor was cracked, etc).

Suggest you get new wires, dist cap, rotor in addition to elec ignition.

Get the new coil as well.

I installed mine to improve idle and solve an overheating problem.
Now it idles very smoothly and stays with temp limits very well.

Joey, any reason you ordered the 3000, I should think the XR 700 should do about as much as could be done. Supposely the 3000 is for a rev limit of 6500 rpm's. I don't think th 4.5 will ever get near that. The SR 700 rev limit is 6000 rpm. What should I do? Anyone? I have decided to go with the Crain unit, and thanks for everyones input.

I would choose the 700 if I had to do it over again.

I went with the 3000 based on the posts I saw,
which was before I found this great forum.

Seems the 4.5ers were using the 3000, and the inline
sixers were going for the 700.

Got mine from an online hi-perf store with kit, coil and all for around $200. I think the 700 was $20-30 cheaper.

Crane site shows either will work on your car:
http://www.cranecams.com/ignition/appsm.htm

I'm babying mine until I can change the timing chain
and adjust the valves, so I couldn't tell you about
6000 vs 6500 rpms....

Good luck - keep us posted how well it works.

Thanks all, I have ordered the Crain XR 700 with the proper coil, twice the spark of the OEM and no points to fool with, hope it smooths out the engine some. Thanks again.