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Posted by: DennisV Aug 21 2022, 06:10 PM

Who has tackled rebuilding their own Marelli distributor, and to what level of success?

I can find a few core candidates on eBay and the classifieds. What makes a good core?

There are rebuild kits and parts now. I've found a couple videos and tutorials. The mechanical seems reasonable. I have access to a media blaster for cleanup.

What I don't have is a Sun machine or way to check the centrifugal advance when I'm done. What are the other pitfalls that make sending one out for restoration a $500+ job? What is the worst case outcome if it's messed up and put on an engine?

Thank you.

Posted by: 914Sixer Aug 21 2022, 06:34 PM

Unless your dead set on using the Marelli, find a 911T Bosch replacement.

SparxWerks.com in Arizona can set your specs on old school Sun machine, may even be able to do the Marelli.

Posted by: DennisV Aug 21 2022, 09:03 PM

Thanks for the SparkWerks suggestions. I'll see what they're interested in doing, and add them to the http://www.914world.com/bbs2/index.php?showtopic=361209t.

Our car is a 1970, and I believe that Marelli is correct for that year. It appears that Bosch is a more popular brand, but best I can tell that is because parts had been hard to get for the Marelli. Not that it was a particularly bad design. I'm open to being corrected on that. It seems Marelli parts are more widely available these days. I will find out soon enough on both points (bad joke intended).

Posted by: fiacra Aug 21 2022, 09:59 PM

If you decide not to do it yourself I'd also suggest Vintage Werks in Washington. They do all the distributor refurbishing for my local independent Porsche shop. Their website can be a bit misleading as at first glance it looks like they only do old VW distributors, etc. They recently refurbished my distributor and it was just over $200. They charge $175-225 (plus parts) depending upon the distributor. They have a Sun distributor tester as well and sent me a graph with the advance curve.

Posted by: gulf908 Aug 22 2022, 12:39 AM

. . . Our car is a 1970, and I believe that Marelli is correct for that year . . .

Dennis

according to the workshop manual,the Bosch distributors came in in April 1970 and prior to that would have been Marelli
my #1907 is a May 1970 build and has a Bosch distributor
what month was your car built ?

cheers
Dennis

Posted by: DennisV Aug 22 2022, 05:44 AM

According to the info I got from Dave Pateman, ours was built in February 1970.

Given there is no date range in the parts catalog for the CDI (aka Control unit BHKZ) I'm guessing the Bosch (no condenser) is compatible?

I told myself I wasn't going to obsess over the originality on this car like our 356, but here I am...

Posted by: rgalla9146 Aug 22 2022, 05:46 AM

I have a Marelli dizzy in a 914 6 that runs very well indeed.
I can site a direct comparison to my long time 6 that has a 911 S dizzy.
I don't have any info to offer other than the car was originally serviced in California
at Scientific Automotive (?)
I would contact Kurt at PartsKlassik. They offer parts and rebuild service.
Ask for his opinion and advice. I have no connection to him.

Posted by: ClayPerrine Aug 22 2022, 08:06 AM

Our six originally came with a Marelli distributor, but it had a Bosch replacement distributor in it when we got it. Once Porsche Classic starting carrying the Marelli cap and rotor set, I took the time to disassemble and clean the Marelli. It was fairly easy.

The shaft comes out, and the advance gets disassembled. Clean and lube all the pivot points on the advance mechanism, and make sure you put the springs back in the same spot they came from.

I used an old Sun distributor machine to check it (owned by Zims). The advance was right on the money.

You can call Zims (www.allzim.com) and find out how much they charge to rebuild a distributor. But they have all the right tools and the experience.

Good luck!

Clay

Posted by: dr914@autoatlanta.com Aug 22 2022, 09:03 AM

we have PERFECT caps and rotors for the marelli Had a thousand of each made about ten years ago, then all of a sudden they began to pop up on the internet. We bought one set and they actually both were marked with our logo "auatl". Someone copied what we had done but did not realize that our logo was not factory original!!!!

Posted by: Dave_Darling Aug 22 2022, 05:30 PM

Bosch swaps were really popular for many years, because there were no Marelli parts available. It's good to see that there are now some out there--thanks for making them available, George!

--DD