SPF/Olthoff install alternator issue

[Mike Christian]

I went for another drive today....the car started with what I thought was a sluggish battery. I should have thought more about it, but I didn't. The charging light didn't come on and the ammeter read a slight charge.

Driving up the windy roads toward town to register the car, the ammeter was jumping pretty hard towards negative and then neutral. I am now about 6 miles from my house and the charge light is flickering every now and then but by now it is showing a pretty high negative rate - the cooling fans were on. I pulled over to troubleshoot on a road that I know my wife will be returning on in about an hour...not too far from a winery (just in case).

I shut down to investigate and find that the nut to the ammeter output teminal is backed off most of the way and the wire is loose - not really touching the post. I have no tools. Someone stops by but they don't have tools either.

In an hour my wife stops by and heads to get tools and a jumper cable.

Fifteen minutes after her return, I have tightened the connection and restarted the car. During the first part of the short 6 miles back to my house, the ammeter shows proper charging. About two miles from my house the ammeter starts showing a large negative again. The alternator is not charging at all. I get the car home and look into it further - rather frustrated at this time. The pictures attached show that there was some arcing - the terminal is burnt and the alternator post insulation is melted (the post is loose too).

The location of the alternator makes getting to it difficult.

I am asking Olthoff to send a replacement alternator out. Not sure yet what his response is.

Bummer.

Mike

 

[Ron Earp]

Mike, not much help at this point but now I always put a blob of silicone on the thead/nut on my alternator connections on the race cars. Keeps those nuts from backing off with the high vibration levels and is still removable with a tool.

We had one back off just like that, shorted on the block/bracket and toasted the wire and alternator during the 13 hour enduro last year. Was not cool, cost 30 mins in race time to replace.

Probably be easier to replace yours one from the bottom if the alternator is down low, but I don't know how SPF has dressed the engines.

Ron

 

[Mike Christian]

Ron,

I am asking Dennis (in an email) to provide me guidance as to best replacement method. There is a pretty large access panel behind the seats.

I will post what my solution ends up being. I am hoping that I am not hung out on my own on this and have to pay out of pocket to fix this...seems like an installation issue to me. We will see.

Regards,
Mike

 

[Rick Muck- Mark IV]

Be sure to use a quality new or reman alternator. Your average "parts store" unit has VERY cheap bearings (I get a trade advert and they sell for less than 70 cents so you decide the quality..) and the insulation on the windings will often soften or melt when installed near the headers.

As these are often spun to speeds that were not common on a pickup truck, it is worth the extra safety to buy a well built unit intended for hi-revs and high temperature locations.

And it is acessable via the panel in the bulkhead with the seat out. On Safir P1116 it was much faster to remove the seats and the panels than to curse and cuss at the lack of room.

Rick

 

[Rick Muck- Mark IV]

Also keep in mind cars such as this need some "fettling" and shake down. Even the best install by qualified and diligent people can have a "loose nut" or some such fault.

Keep the drives short and close to home until you are confident of the reliabilty. P1116 took a long period of gestation to solve a cooling issue (cheap reman water pump used in the engine build), a poor throttle cable design and of course, a flood of water leaks in the rain at speed.

These things aren't Benzes people, they take some fiddlin' to get right.

Rick

 

[Sandy]

It's hard to tell how bad the insulator is, but if all it was was just a loose bolt with some arcing to the metal, sand the connections clean, and use a washer and a locking bolt and you should be fine. If it did melt the insulator on the alternator, yank it and be safe.

Sandy

 

[Mike Christian]

Dennis is sending out a replacement and I will change it out to remove all doubt. Thanks Dennis!

Mike

 

[Mike Christian]

Rick, I understand what you are saying. My drives have all been round trips locally. My bad for not taking some basic tools.

I think I need to preflight this car like I do the plane...

Mike

 

[chuck smith]

I could almost rebuild the motor with the tools I take on my trips in the 40 or the cobra

 

[Mike Christian]

well, the saga continues albeit slowly. I finally had some time to work on the car. Getting the alternator out wasn't that tough after pulling the seats and the engine cover on the bulkhead. Putting the replacemt in was a problem. The casting of one of the mounting ears was too thick - about 1/16" thicker and it wouldn't fit in the lower bracket. Now I have a choice to machine the casting of the replacement alternator or rebuild the original alternator. Luckily I was working at my hangar and two of the local plane mechanics came over to see the car. They told me of a shop that overhauls alternators and starters right down the road. I take it to them at 3pm and they say it will be as good as new by noon tomorrow - for the pricey sum of $20. Shweet. I might get to driv this car and get it registered this week...

Mike

 

[Mike Christian]

So not only were they done early, but they only charged me $10. They took the original one apart, tighened the post with new hardare, replaced the insulator and tested it. I put is back in the car and it works fine.

Here is a picture of the access via the top bulhead cover plate. There are two lower ones also - behind the lower seat backs.

Back on the road!

Mike

 

[Gary Kadrmas]

Mike,

Were you going to repost the pictures of the access plates?

 

[Mike Christian]

Sorry about that - here goes. This should give you a good idea of the access.

The car is now registered in the wonderful state of Oregon!

Mike