the alternator on a v8 super car does nearly 18 thousand rpm. thats at full noise so about 7500 to 8000 engine revs and is driven from the flywheel ring gear(this was a few years ago dont know what they do currently)

yes phil they are much more efficient electrically and weight wise. most alternators are actually 3 phase and thus give a very smooth output to the rectifier. but like a generator you only get out what you put in so if the drive isnt upto snuff they wont work properly. alot of poor alternator performance can be fixed by changing the belt and setting correct tension. bad grounds are also a common problem.

langdon that is what i was describing. see the chain thats what i know as a love-joy coupling it allows for little misalignment and cushion the drive forces abit. and yes it will spin at the same speed as the original generator as its coupled inline rather than offset.

that the advantage of what i did is it allows you to get a stepped up drive speed so its working properly at lower engine revs. and at a wider rev range.

My D8's generator drive does 1000rpm at 450rpm idle and 2666rpm at 1200 engine rpm. As I said it won't charge at maximum Amps but it will charge your batteries.
One chart I found on the alternator curve shows that the alternator starts charging at 1050rpm and rises very fast so at 2600rpm it is putting out about 80 percent of its rated capacity.

trainzkid88 wrote:

yes phil they are much more efficient electrically and weight wise. most alternators are actually 3 phase and thus give a very smooth output to the rectifier. but like a generator you only get out what you put in so if the drive isnt upto snuff they wont work properly. alot of poor alternator performance can be fixed by changing the belt and setting correct tension. bad grounds are also a common problem.

langdon that is what i was describing. see the chain thats what i know as a love-joy coupling it allows for little misalignment and cushion the drive forces abit. and yes it will spin at the same speed as the original generator as its coupled inline rather than offset.

that the advantage of what i did is it allows you to get a stepped up drive speed so its working properly at lower engine revs. and at a wider rev range.
 

That is a chain coupling that Lovejoy don't make. Will not cushion the drive forces. Not sure why they didn't use a jaw type coupling as that would provide a smoother coupling.

yes the jaw couplers are better and most have a rubber segment which does give some cushion there is pin type ones too some have woven material like conveyor belt as the interface between the halves.

those chain couplings are simple 2 matching pitch sprockets and a double row chain with a joining link probably cheaper too.

By pin type do you mean cone ring rubber couplers? These are rubber rings mounted on bolts on a flange with corresponding holes in the secondary flange.

If the drive was built correctly then you could even use a non flexible coupling

thats another type but same basic idea, the uncle saved a big chicago pneumatic compressor from scrap that had that kind of coupler. (the plan is to use it as a dummy load for a 3cyl ruston diesel. that was also owned by the city council.
what im talking about is a pair of discs with a rubber/canvas piece in between each of the discs has 2 pin the engage the rubber or canvas block 90 deg to each other.

yes if correctly aligned and supported no reason why it couldnt be solid coupled.

Ah yes I know the ones you mean now. Very old technology. Last time I saw one used was on an old 1930's pickup trucks steering column.

it was still used in the 50s. and still has its uses. my cordless angle grinder had the same kind except it was soft rubber till it broke and has been upgraded with a insertion rubber one. wont break again.

PhilC wrote:

My D8's generator drive does 1000rpm at 450rpm idle and 2666rpm at 1200 engine rpm. As I said it won't charge at maximum Amps but it will charge your batteries.
One chart I found on the alternator curve shows that the alternator starts charging at 1050rpm and rises very fast so at 2600rpm it is putting out about 80 percent of its rated capacity.
 

Thank you for sharing that.  Knowing the relevant RPMs is very handy.

Whats your serial number? Some 212 Graders were equiped with the Direct Electric start option. I have run and did repairs on a 212 that is serial number 79C-42. It is a 1955. These were available 1954-1957. This came factory equiped with 24 volt direct electric start. My serial book does not show an end number for production, but the beginning number for 1957 was 97. The easiest way to tell is if it was originally equiped this way is look to see if it has glow plugs in the head? It will have a switch in it like this D2. The switch is near the hydraulic pipes. If not, Someone has coverted it in the past.