HurricaneCurt Posted February 23 Share Posted February 23 I recently became the owner of a 46 Roadmaster Series 71. Car is mostly original as best I can tell. I bought the car for short trips around town and have been having trouble keeping a charge (battery is good). System is still 6V. I decided to buy a Powergen one wire alternator from Powermaster to keep an original feel. The problem I have is that the car uses a 1" v-belt and the biggest pulley I can find is for a 3/4 belt. The pulley on the generator is keyed and the shaft on the alternator is not. I have spoken with the people at Powermaster as well as several automotive suppliers and they just throw up their hands. I have called all over with no luck. The best I can figure my options after several calls are either A) to have a keyway cut into the shaft of the alternator, which, I am sure that will void any warranty or B.) pay a machine shop to make a pulley out of billet. I am sure option B will cost several hundred dollars. Logic would dictate that if they make a 1" belt, they should make a damn pulley for it, lol. Any advice would be greatly appreciated. I am including photos of the belt stock numbers, the pulley in question, and a detail of the generator pulley from the shop manual. Link to comment Share on other sites More sharing options...
JohnD1956 Posted February 23 Share Posted February 23 I cannot answer your pulley question but i do wonder why you think the original generator is the problem? A quick look at your pictures shows a different but related problem, in that you still have the cloth insulation covered wires. The presence of gobs of black electrical tape seems to scream potential short circuits. Another different but related question is what size battery cables do you have? The 6Volt systems require the thickest cables, which I believe are 0-0 guage ( but don't hold me to that guage as I am not an expert, I just know it is not the same as the thinner 12 volt cables). At any rate, sending 28-30 amps into the deteriorated wires may be suggesting a voltage loss (represented by heat) due to the resistance of deteriorated original wires. And sending 60-90 amps thru those same wires may result in badly overheating those same wires. This is, in my opinion, a dangerous modification without a new wiring harness. 2 1 Link to comment Share on other sites More sharing options...
HurricaneCurt Posted February 24 Author Share Posted February 24 Hello John! The current generator does not function at all. I either need to rebuild or replace it, so I feel like I might as well go to an alternator. As she is now, I have to charge her after 5 or 6 starts. I cannot drive at night because the lights are so dim. Another issue is that I drive only very short distances, less than 5 miles, and at slow speeds (less than 45 mph). I feel that the generator will not sufficiently charge the battery. They do not charge at low rpm. The wiring is going to be replaced. I am in the process of ordering new cloth covered wiring harnesses for her. With a one wire alternator, a single wire will be run from the alternator to the battery, bypassing the cloth wiring and charging the battery directly. Link to comment Share on other sites More sharing options...
EmTee Posted February 25 Share Posted February 25 I certainly can't say for sure, but it sounds to me like there may be at least two or three problems combining to create the poor performance you're experiencing. Old, corroded wires with partially broken internal strands, possible undersized battery cables and finally an over-taxed, undercharged (and sulfated?) battery are all things to look for and correct if necessary. Link to comment Share on other sites More sharing options...
HurricaneCurt Posted February 25 Author Share Posted February 25 The battery is brand new. The generator does not provide any charge whatsoever. I have a tester and have tested it. The battery cables are new. 1 Link to comment Share on other sites More sharing options...
JohnD1956 Posted February 25 Share Posted February 25 7 hours ago, HurricaneCurt said: Hello John! The current generator does not function at all. I either need to rebuild or replace it, so I feel like I might as well go to an alternator. As she is now, I have to charge her after 5 or 6 starts. I cannot drive at night because the lights are so dim. Another issue is that I drive only very short distances, less than 5 miles, and at slow speeds (less than 45 mph). I feel that the generator will not sufficiently charge the battery. They do not charge at low rpm. The wiring is going to be replaced. I am in the process of ordering new cloth covered wiring harnesses for her. With a one wire alternator, a single wire will be run from the alternator to the battery, bypassing the cloth wiring and charging the battery directly. Sounds like you have it in the process of full correction. Do you still use the gas pedal starter function? If so, I understand you need to order the correct unit to preserve that function. Link to comment Share on other sites More sharing options...
195354 Posted February 25 Share Posted February 25 Curt welcome to the forum. The advice and expertise on the forum is almost limitless I know it has helped me on my projects. Looks like you are on the repair path. Here are a few things I have learned the hard way in some cases. For a little background I drive a 53 RM every chance I get it has a generator and I get by fine, I even added AC so the amp draw is high at times. This is 12 volt not 6 volt for reference. This car was new to me 2 years ago it did kind of run. I did the starter and generator brushes and bushings. My regulator was OK. I wish I had added an electric fuel pump before I drove it much. I use this if needed to fill the carburetor bowl or when a vapor lock comes my way. I also changed the battery cables they had corrosion inside the cables. After 70 plus years yours are most likely the same. I do see the ground strap it looks new. If you have a new battery a tuneup could help with crank time before it starts. Resolving the charging system take this to a local starter shop see about repairing the generator. I like the starter switch on the gas pedal. I have read somewhere on the form that an alternator can cause issues with this. I would think with a battery tender and a working charging system you would be OK. With low starter draw and quick starts and fully charged battery. Another thing that I install is a battery switch new wire harness or not. I never leave an old car with the battery hooked up. I would also look for any parstic draw on the system while it is hooked up. I have seen the glove box light or a trunk light be an issue. I did change one car from 6 volt to 12 volt it is not a Buick it has worked fine 30 plus years. This is not hard and it does simplify a few things. Now the issue with your pulley. I would think the pulley would work without a keyway. This is if the pulley is tight against the bearing retainer/spacer in the new alternator. Once the nut is torqued down the pulley should pinch pulley tight. I have installed many an alternator that have no keyway. I added a picture of what I see on alternators that press against the bearing. They just rely on the nut holding pulley tight against the bearing retainer. The local rebuilder should be able to help with this. My local rebuilder has parts and pieces for many generators. Keeping posting how this is going for you. Looks like a clean unit post a few pictures of the car. Drive it and enjoy the ride. Steve 1 1 Link to comment Share on other sites More sharing options...
HurricaneCurt Posted February 25 Author Share Posted February 25 So the story I got with the car is the the original owner passed away and it was sold to someone who rebuilt the engine in 2012. His intention was to do a frame off restoration. The power cables were replaced at that time. There is no delay in starting. I pump the pedal 3x, turn on the ignition, and she fires right up. She drives great. I have had to replace the torque ball seal to fix a pretty nasty leak and the rubber brake lines. The brakes work great, but we are going to put new cylinders and springs on (I have pads just in case). Other than that she is a survivor. I have had her for 4 months now. She has 58,000 original miles and turns heads wherever I go. She is my only car (50th birthday present to myself) and I want her to be a solid daily driver. Her name is Miriam and she is the coolest thing I have ever owned. 3 Link to comment Share on other sites More sharing options...
195354 Posted February 25 Share Posted February 25 Cool car If you did the torque tube seal nothing on this will keep you away from the roads as far as repairs. Get it charging and drive it as often as you can. I like doing the repairs sounds like you do also. The best times are taking a ride with family and friends going wine tasting or to the local DQ with the grand kids. Add a long trip and you will be the hit on the highway. Steve 3 Link to comment Share on other sites More sharing options...
old-tank Posted February 26 Share Posted February 26 6 volt batteries require a longer charge time usually overnight versus 2 to 3 hours for a 12 volt battery. The later 320 engines used a smaller belt and pulley, maybe you can find some to swap. 1 Link to comment Share on other sites More sharing options...
JohnD1956 Posted February 26 Share Posted February 26 That is a beauty! Link to comment Share on other sites More sharing options...
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