So I just got the 216 in my roadster running and while I was at the showdown the car just quit and the starter wouldn't crank when when I tried to restart it. When I got back, I checked the charging system and I think I may have an issue. When the car is idling, its at around 12.2 volts but drops about 1/10th of a volt every 30 seconds with a meter across the battery. Then at around 1500rpm, I've got 13V at the battery, and it revved up a little more, I get 14.6V max. Does anyone see any problems here? Anything else I can look at?
Couple things come to mind.. Maybe a short somewhere causing a power drain or maybe a bad battery? Is this a new build or has the car been together awhile and these are sudden new problems? Are you running a generator or alternator?
Its a new build but the battery is about a year old. Only have 3 circuits running right now, run circuit, fuel pump, and fan so it should be easy to trace down if there is a short.
Remember generators do NOT put out below 800RPM os so and full output doesn't happen untill about 2000 RPM. And electric fans are power suckers.
Make sure your Engine is grounded to the Chassis, and you must have polerized the regulator to make it even charge at all. are the brushes good in the Gen? good luck one of the reasons Alt in my truck
Your charging system seems to be working using these voltage numbers at those speeds. You might get the battery load tested to confirm that it is good. I'd check all the cable connections too. A poor connection will show voltage but may not be able to carry the current load of a start up. It was a common thing to have dirty battery cable connections prevent the car from starting even though everything else is working fine. I learned the hard way laying on my back replacing the starter motor in 20 degree weather only to find that my battery terminals needed to be cleaned.
All of the above. If possible, get the car on a VAT tester, that will check starting load, charging and the works. Bob
Too bad that an alternator is ugly, and a generator is beautiful.....just the opposite of how they work.
Had a issue with my gen at the showdown but found a regulater for 5 bucks in the swapmeet got me going again. now im gonna start buying em up for spares when i see them.
generators do not charge at idle.....alternators do charge at idle....try installing a smaller pulley from an alternator onto your generator....this will speed it up a bit at slower engine speeds...you don't ever want to overspeed a generator because bad things happen internally ( throwing solder)....since you are running a 216 inline, I don't think that you will have any worries about high rpms and the generator...If you swap the pulleys, they do interchange...I've done this the opposite way by putting a wide belt pulley from a 41 Buick generator onto a late 60s alternator.....works great !!...just reduce the generator pulley diameter and you should be fine.
I'm late to the party but I go along with Tommy said in that it appears that your generator is working correctly for the speeds you indicated. As cool as people think they are they have one big problem and that is that they don't charge much if anything at an idle or real slow speeds. That isn't a problem if you don't have a bunch of stuff drawing power out of the battery faster than the generator can put it back in. If you were in a line of traffic for a long time getting into the show and idling most of the time the fan could have drawn more power out of the battery than the generator replaced and left the battery low even though everything was working right. I'd find out how much draw the fan has amps wise and maybe how much draw the fuel pump has. And are either a necessary item? Would a mechanical fan work on the car or would a mechanical fuel pump work in it just as well? The other thing as Tommy and some others said is are your ground connections really making good connection? I've seem more guys with all kinds of vehicles fight starting and charging issues due to bad ground connections than any other thing. Did you scrape the paint on the block to bare shiny metal where you connected the ground strap? Guys with freshly painted in hotrods are often guilty of not cleaning off the paint under the ground strap well enough because they don't want bare metal to show. Are the battery connections clean and tight? Are the connections from the clamps and ends of the cable tight on the cable wire and are they corrosion free? Is the top of the battery clean and dry? If you put one lead from your volt meter on the + post and the other anywhere on the top of the case of the battery do you get a reading? That's not too likely with a new battery but happens a lot if the battery is where dirt and moisture can get on it.
Well heres a little update. I swapped out the batter for a deep cycle optima i use to operate the winch on my trailer. Battery is about 4 years old, has about 100 less cranking amps and I haven't had an issue with it. Been driving the piss out of the car the last half of the summer. No issues with starting or charging. Haven't had a need to charge the battery with a charger. Even after sitting for the past month, had no problem starting it yesterday. Had to crank it a bit before it would start and saw no noticeable draw or change in cranking speed. So hopefully everything is good.
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