I have a 1951 flathead V8 and I was wondering what alternator I should put on it for a 12 V system. I'm not looking at spending $300 on the ones some of the sights sell. There has to be one that's cheaper in price yet good quality. I will be converting my distributor with a 12 V negative ground pertronix. I will have a 3x2 Edelbrock intake with Stromberg 97. Any help would be greatly appreciated... and while we are in the area of the engine, would you advise to use the wide belt or narrow?
The GM 10/12 SI alternators are very popular and available at most auto parts store, new and rebuilt, starting around $60, depending on amperage needs. If your going to use a non-stock non-loadomatic carb, you'll have to change the distributor to an aftermarket, Chevy conversion, etc. with mechanical advance. Your '51 already has narrow belts, so why change? Depending on the tripple intake chosen, the alternator can be located in the same position as the generator, eliminating the need for an offset bracket.
I'm currently in a build as well with a 51 Merc Flathead V8 and also a 3x2 carb setup. I plan on using either a GM alternator that most use and speedway sells parts and brackets for or I've recently found an article from a guy that used a Ford Mustang 4.6 Bullit alternator. All the info on that can be found here. http://www.precisionenginetech.com/project-engine-builds/2010/12/14/project-flathead-part-6/ Good luck!
If the '51 is a truck engine, it will still have wide belts. Be aware they need a mount different from the Car (narrow belt) to get the belts aligned.
Flatheads will reject alternators. Just say no to alternators. Generators add cl*** and dignity to the flathead. Not to mention your eye sight will be improved not having to look at that ugly thing.
will the speedway part #447-1282 ignitor work with the GM 10/12 SI alternators and the rest of the setup i have
If you think you really need an alternator, OK. If you just need 12 volts, anyone in Wisconsin should be able to find a generator from a 56 to 63 Ford pickup, up to F 6. Take your stock generator and the 12 volt to a reputable rebuilder and tell him to make you a 12 volt early model generator. It should not cost more than a good quality alternator. Control it with a regulator from a 57 Ford pickup. Sometimes the bigger truck generator had a bearing on the rear of the armature. Simply turn the rear of the armature to the ID of the bearing and use the newer rear plate. It will look right, and if kept clean and dry it should last nearly forever. Have the rebuilder tell you how to polerize it, and write down the instructions.
The ignitor only replaces the points, and has nothing to do with the advance. You may want to try and learn more about your flathead and it's ignition (or basic ignition systems) from a '49-'51 shop manual, old Motors, etc., (something you should have anyway) before you start throwing money/time at your engine.
The cheapest way to get 12Vs is to just put a 12 generator body over your 6V armature. Ask around. A buddy gave me his 64 Fairlane generator that I used on my 32 Ford with an 8BA engine. No pulley to buy. Do a search. It was done a few years ago now. I had to buy a 12V regulator but that was all. I'm a cheap****e too!
As usual Z this type of question gets a couple of decent and practical answers such as the one V8 Bob made and the cadre of oh no you can't do that's come out of the woodwork to tell you to do it their way and spend a lot more doing it. The GM 10/12 SI alternators are inexpensive and hell for easy to find. The kit to mount one would no doubt cost more than a lifetime alternator. Speedway sells a bracket that makes it a bolt on deal but if you have the wide belt you will have to work a bit to make it work with the wide belt. If you have the narrow belt setup it's a bolt on deal. I'd ask if it clears the carb setup though. http://www.speedwaymotors.com/Plain-1946-1953-Flathead-Alternator-Bracket,4242.html
When I switched to 12V, I got the 1 wire alternator from Powergen that is made same size/look as the original generator. I haven't had a single hiccup from it yet! (3 yrs running.)
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