M20C. Bendix Vs. Slick

[Jim Peace]

What would be the bendix part numbers for an o-360A1D?

 

What else would I need?

 

1964 M20C?

 

Thank you

[Andy95W]

Left magneto: S4LN-200, Part # 10-163005-2

Right magneto: S4LN-204, Part #10-163045-3

You will also need new wiring harnesses.

[orionflt]

Slick has at least four Service Bulletins calling for inspections of mags and parts since 2006. These parts were failing at very low time in service. Dozens of mags I examined at or below the 250 hour threshold called out were within a few hours of failure due to problems with points, point cams worn out, rotors with loose tangs, distributor blocks with loose or worn out bushings, carbon brushes wearing out and snapping off, and partially stripped gears (due to the loose bushings). Several had already jumped a tooth and were out of time. Slick mags used on Continental IO-360ES engines had several failures of the hold-down clamp area on the housing. This allows the mag to basically fall off the engine and lose most of the oil in the process. A trip around the pattern lost 5 of the 7 quarts in the pan. This housing failure was not an overload or improper maintenance procedure, it was a result of poor casting and a void or crack. The several I saw had less than 500 hours since new and were on brand new engines.

There are also problems with the coils, particularly in the output tab that the rotor's carbon brush rides on. Factory misalignment is quickly wearing out the tab, which mandates a $300 coil replacement.

Slicks built before 2006 seem to be unaffected, but mags built or serviced after that date have questionable parts. I have seen no evidence that they have solved these QC problems yet. Champion bought Slick a few years ago, and they have been so wrapped up with the crappy spark plugs that they may not have solved the mag QC problems. Time will tell, we just need more people willing to be test pilots for Slick.

If you operate Slick mags you would be wise to do the 500 hour inspection at 250 hour intervals until you are satisfied that the problems are gone.

Worst of all, Slick parts prices are high enough that you can easily spend $500 at each 500 hour inspection for points, condenser, distributor block and rotor and labor. Throw in a coil and you are at $800, per mag.

Slick did have an issue with the mags wearing improperly and causing early failures on some of the 6 cylinder model mags but there service bulletin that went out covered all mags manufactured during that time frame. In all I only heard of a handful that actually failed in flight, but it is my understanding that slick did send out a lot of new kits to repair mags that were improperly wearing and found during the mandatory inspection. I have a set of mags from that time period installed on my plane and have never had an issue with them, in fact when the mags went out for overhaul the parts removed looked almost new. You also mentioned mags separating from their hold downs.... If your talking about the nuts and clamps that hold the mag to the engine, that is not an issue with the mags but an issue with the proper installation ie mags not. Being properly torqued to the engine and it doesn't matter what mag is installed. I'm not sure what issue you actually have with the slick mags but you have bashed them pretty good here, from my experience working on aircraft both mags are comparable. As with anything you are going to have issues and failures, if you compare bendix and slick they both have had issues that to deal with, slicks just happen to be the most recent. As other have stated what it comes down to is what you choose to install or keep installed. I am not unhappy that I switched from bendix to slicks, in fact at the time it was the best choice, would I do it today? Probably not. Why? Back when I switched the mags were cheaper new and cheaper to repair, now that champion has bought them the prices have jumped no longer making it more economical.

One of my favorite. Quotes is" opinions are like a$$h0les, every body has one....."you can finish the rest, it doesn't matter what everybody else thinks it matters that you are happy with the decision you made.

Brian

Sent from my iPad using Tapatalk

[philiplane]

I'm perfectly happy to bash bad products and recommend good ones, and change opinions when products change.

 

The broken flanges were found to be a manufacturing defect, as I reported, not an installation error. That is why it's important. They didn't know how many were affected. This has also happened on Bendix magnetos back around 1973. The ones affected had slotted mounting ears with porosity in the ear base. They would crack but not separate. The Slicks affected do not have the same style ear, but only a flange that is retained by a clamp, and that flange has similar casting flaws only on the left flange area, near the parting line.

 

They're hardly comparable, Slicks have much smaller distributor blocks which contribute to misfire at altitude, generate less spark energy due to the smaller coils and magnets, and have much lighter gears, bushings, and point cams. All these are a result of the "lightweight" design, which they once promoted as a virtue, but have since abandoned.

 

My observations are based on a very large data set. I have maintained individual customer planes, and fleets of aircraft that collectively accumulate upwards of 10,000 hours per year over the past two decades. My high point was 2004 when I hit 15,800 fleet hours in a year. That generates over 60 of the 500 hour magneto inspections in one year. And 120 when the parts do not last 500 hours. 

 

See for yourself, more photos of failed Slick parts here: https://www.dropbox.com/home/Slick%20mag%20junk