The Ford Barn

Henry Hopper · 02-14-2022, 02:12 PM

I have a generator that only seems to put out 12.5v at higher revs.. during heavy traffic driving it hovers around 11/12v. If a smaller pulley was used would this give me the required voltage at lower speeds ie;30 mph?
Next question, .. if it would work is there a smaller pulley available and what size is it..... part number etc?

Thanks.

Bob C · 02-14-2022, 02:41 PM

What size pulley do you have now, what generator are you using?

Henry Hopper · 02-14-2022, 03:05 PM

The motor is a 40/41 in a 32 roadster..I’m not sure of the pulley size, I’ll have to measure it. ... I am just mulling over the theory and wondered if a smaller pulley size would give enough extra revs to satisfy charging.

Phil Gillespie · 02-14-2022, 05:04 PM

Quote:

Originally Posted by Henry Hopper

The motor is a 40/41 in a 32 roadster..I’m not sure of the pulley size, I’ll have to measure it. ... I am just mulling over the theory and wondered if a smaller pulley size would give enough extra revs to satisfy charging.

Have you checked battery condition with a multimeter? Maybe its fully charged and therefore you wont see a high voltage charging rate.
Phil NZ

Mart · 02-15-2022, 07:29 AM

Hi Nige. My truck is similar and I have come to the conclusion that's just the way they are. As long as the battery does get a good burst of charge when the speed is up and it takes a good charge soon after starting I have found it is ok.
I don't know why, but you won't get a constant circa 14.2 volts like you might with a alternator.
I've stopped worrying about it.
Mart.

Henry Hopper · 02-15-2022, 10:18 AM

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I noticed your vids on the subject Mart.. the previous owner said that he drove it for miles and miles without any issues... he changed the voltage ref three times but it made no difference evidently. It’s probably just me over worrying as usual��

02-14-2022, 02:12 PM	#1
Henry Hopper Senior Member Join Date: May 2010 Location: N.W.England Posts: 439	Pulley size ? I have a generator that only seems to put out 12.5v at higher revs.. during heavy traffic driving it hovers around 11/12v. If a smaller pulley was used would this give me the required voltage at lower speeds ie;30 mph? Next question, .. if it would work is there a smaller pulley available and what size is it..... part number etc? Thanks.

02-14-2022, 02:41 PM	#2
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,755	Re: Pulley size ? What size pulley do you have now, what generator are you using?

02-14-2022, 03:05 PM	#3
Henry Hopper Senior Member Join Date: May 2010 Location: N.W.England Posts: 439	Re: Pulley size ? The motor is a 40/41 in a 32 roadster..I’m not sure of the pulley size, I’ll have to measure it. ... I am just mulling over the theory and wondered if a smaller pulley size would give enough extra revs to satisfy charging.

02-15-2022, 07:29 AM	#5
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,755	Re: Pulley size ? Hi Nige. My truck is similar and I have come to the conclusion that's just the way they are. As long as the battery does get a good burst of charge when the speed is up and it takes a good charge soon after starting I have found it is ok. I don't know why, but you won't get a constant circa 14.2 volts like you might with a alternator. I've stopped worrying about it. Mart.

02-15-2022, 10:18 AM	#6
Henry Hopper Senior Member Join Date: May 2010 Location: N.W.England Posts: 439	Re: Pulley size ? Sponsored Links (Register now to hide all advertisements) I noticed your vids on the subject Mart.. the previous owner said that he drove it for miles and miles without any issues... he changed the voltage ref three times but it made no difference evidently. It’s probably just me over worrying as usual��