Alternator Conversion - Does your car talk to you?

Post by: **alexblack13** » Mon Jul 11, 2011 9:25 pm

Good job! let me know if you have trouble getting the spacer you need and I will make you what you need and send it over.

FOC... Including postage! A small donation to BHF as normal will do...

Let me know..

Alex B.... :wink:

Post by: **Galwaylotus** » Mon Jul 11, 2011 9:33 pm

Thanks, Alex. As I said once before, you're definitely one of the good guys. I should know in a day or two if I can get what I need. I'll let you know if I need to avail of your offer. Thanks again!

Post by: **UAB807F** » Tue Jul 12, 2011 5:06 am

On mine I ended up making a custom lower mounting bracket, but for years ran it with a combination of dynamo bracket plus spacer tube. I think you can buy the correct bracket for an alternator (Sue Miller ?) as it was a Ford part. Sue certainly sells the correct length fan belts as well, I bought one at the end of last year from her.

Not wishing to teach granny, etc, but on my 17ACR the rear lower fitting had a small tube in it. Apparently this was designed to move slightly as the bolt was tightened so the correct procedure was to tighten up the front upper & lower mounts and then adjust/tighten the rear lower mount. Doing it in reverse order could, apparently, snap off the front flange.

I don't know if things have changed with modern 17ACRs or even if the whole thing was one of those mechanics myths, but I'll mention it just in case - wouldn't like to see you with a brand sparkly new but broken, alternator !

Brian

(ps - kudos on changing the wiring ! You can also buy the correct plug to go on to make it even neater - after 30-odd years I bought one from Ebay :oops:

)

Post by: **bast0n** » Tue Jul 12, 2011 5:26 pm

Galway Lotus

You may be interested in my twin pulley setup. The posts are in Things in common under
"Alternator install questions"

I have not been as lucky as Alex as my belt slipped quite a lot when my huge electric fan came on, especially when going through heavy rain and sodden roads and I was/am nervous of overtightening the water pump belt. If you want any advice PM me and I can send you some drawings - same for anyone else interested.

Have fun and don't grow up too quickly! David.

Post by: **Galwaylotus** » Wed Jul 13, 2011 9:06 pm

A couple of points for updating - and one more question (as Colombo would say). When I bought my new ACR 17 alternator the other day, I had the pulley and fan from the dynamo swapped over to the alternator. Now I'm not so sure that was the best thing to do. The pulley from the dynamo is larger than the on that came with the alternator. With the dynamo pulley, the speed ratio will be approximately 1.5:1. At 7000 rpm engine speed that's 10500 alternator rpm. At 900 rpm engine speed tha laternator is running 1350 rpm. I don't know what the alternator output is at that low rpm. An internet search turned up a recommendation of 3:1 for street use. The same article said alternators can take up to 20,000 rpm for short periods so I wonder if I should put the smaller pulley back on. I don't have it here to measure but it probably is something less than a 3:1 ratio. What's the consensus?

The second point is for Alex. When sourcing some Imperial hardware for installing the unit, I asked about getting some tubing for a spacer. The shop deals in hydraulics and gave me a short piece of heavy wall hydraulic tube with an internal diameter just about perfect for the bolt! All I need to do is cut it to the length I need. That was a bit of good luck!!

So, Alex, thank you once again for your kind offer but I won't need to impose (this time!!!). :lol:

Post by: **UAB807F** » Wed Jul 13, 2011 9:21 pm

When I got my alternator I never even thought about changing the pulley, I just bolted it in place and sorted out a fan belt to fit from the local Halfords stock. In fact it's easier now because Sue Miller stocks the correct length belt !

I thought alternators were supposed to run faster than dynamos anyway ? (but that could just be an example of fading memory cells......)

Post by: **alexblack13** » Wed Jul 13, 2011 9:36 pm

UAB807F wrote:
I thought alternators were supposed to run faster than dynamos anyway ? (but that could just be an example of fading memory cells......)

They don't need to. There is a possibility that when the twinc is at full chat rpm one might over rev' the Alternator and cause damage various.. but, I cant remember ever hearing of this actually happening. If I were setting up a racing engine I would def' get the pulley dia sorted to prevent this from occurring,

Great weather up here right now. Have had the hood down on my day car for quite some time now.. Tis great..

Al' .........

Post by: **alexblack13** » Wed Jul 13, 2011 9:42 pm

Galwaylotus wrote:
The second point is for Alex. When sourcing some Imperial hardware for installing the unit, I asked about getting some tubing for a spacer. The shop deals in hydraulics and gave me a short piece of heavy wall hydraulic tube with an internal diameter just about perfect for the bolt! All I need to do is cut it to the length I need. That was a bit of good luck!! So, Alex, thank you once again for your kind offer but I won't need to impose (this time!!!).

Brilliant.. Job done then?

Alex...

Post by: **Galwaylotus** » Wed Jul 13, 2011 9:57 pm

Not quite! I haven't installed it yet because I've had second thoughts about the larger pulley. I think I'll bring the alternator back and get its original pulley and fan put back. It's a bit out of town so it may take a few days but hope to be able to install it on the weekend. I need to get under tha car to connect my new alternator cable to the starter battery connection. As I have no garage that means jacking it up in the drive and putting everything back together each time. I'm not yet retired so I need to, wait until Saturday when I have enough time to complete the job! :roll:

Post by: **alexblack13** » Wed Jul 13, 2011 10:03 pm

Work is a pain at times eh? Good luck with the fitting of it. It should be dead straight forward..

And what a difference it will make.. :wink:

Al'.......

Post by: **fatboyoz** » Thu Jul 14, 2011 4:49 am

This is what I fitted to my car. Can be run with little tension on the belt (minimum side load on waterpump) and runs the alternator at the correct speed:
http://www.burtonpower.com/parts-by-cat ... s.html?p=6

Also, did you fit the doubler plate to the the front cover where the top mount/adjuster is bolted on? This bracket spreads the load over three bolts instead of just one. Part #21 on this diagram:
http://rdent.com/manuals/plus2/electrical/ma.htm
I obtained this plate/strap from Lotus Marques in Melbourne. "Generator Mounting Plate TC" X050E6004Z.

Colin.

Galwaylotus wrote:Not quite! I haven't installed it yet because I've had second thoughts about the larger pulley. I think I'll bring the alternator back and get its original pulley and fan put back. It's a bit out of town so it may take a few days but hope to be able to install it on the weekend. I need to get under tha car to connect my new alternator cable to the starter battery connection. As I have no garage that means jacking it up in the drive and putting everything back together each time. I'm not yet retired so I need to, wait until Saturday when I have enough time to complete the job!

Post by: **Galwaylotus** » Thu Jul 14, 2011 9:43 pm

Ran my new heavier gage cable to the starter motor tonight and spent time wrapping and tywrapping it to keep it neat. I haven't made off the alternator end yet. I also decided to go with the drive pulley that came with the new alternator I calculate about a 1.94:1 speed ratio which should be about right (at 7000 rpm crank speed the alternator would be turning 13500 rpm. I'm unlikely to be running the engine that fast so alternator should be ok). I did a trial fit and found the alternator is slightly out of line and will need to go forward a bit. No real problem as I can use a few washers between it and the mounting bracket; however, the issue will be the adjusting strap. I'll have to space it forward as well. Looks like I may be making the three-hole plate referenced above! The new belt I bought is too long and the original is too short so I'll be back to the shop to trade it tomorrow. Fun and games!! :roll:

Post by: **MickG** » Thu Jul 14, 2011 10:49 pm

I may be missing something here but why are you running a cable from the alternator to the starter motor? or do you mean starter solenoid.
Regards Mick G

Post by: **Galwaylotus** » Fri Jul 15, 2011 8:35 pm

I should have clarified. I have a high torque pre-engaged starter with its own solenoid. and the alternator has a built in regulator so I can eliminate the control box altogether. The heavier alternator cable now goes from the alternator output to the battery cable that just happens to go from the battery to a stud on the starter (solenoid)! :wink:

Post by: **MickG** » Fri Jul 15, 2011 10:30 pm

I was missing something, Thanks

Regards MickG

Alternator Conversion - Does your car talk to you?

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