VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #71  
Old 10-14-2019, 01:05 AM
Paul 5r4 Paul 5r4 is offline
 
Join Date: Oct 2006
Location: Foley, Al
Posts: 467
Default Rebuilt alternator installed

My 7A is now equipped with an auto alternator. It cost $91.00! The Lester number... (still not sure what that means but it is important!)... is 14684... thanks William Lane! It was literally a drop in replacement for the original Vans alternator that came in the FF kit.

Why did I switch to auto?

I was 120 miles from home when my alt crapped out.
If I would of ***HAD*** to get a PP or B&C alternator, First it would be at the very least $500.00 bucks PLUS shipping to wherever I might be. Second the time wasted waiting on its arrival. When this happened to me two days ago I felt like I was being held hostage.

Now... same scenario. With a couple borrowed tools and bumming a ride to an auto parts store... EVEN ON A SUNDAY... my alternator will most likely be in stock! In another hour I'll have the new one installed, drank a coke, used the bathroom and be ready for take off.

I've read the threads regarding failure rates and quality. I'm VFR only so I'm comfortable not spending 7 or 800 dollars. Even the top brand seems to fail at some point. Even if you get 1000 hours that's great but from reading these threads doesn't seem to be the norm. I got 475 hours from the Vans supplied one and a replacement from them was going to be $475.00 plus shipping and don't forget about the down time. I went with a hundred dollar unit available NOW and If I get anything close to 300 hours I think I'll be happy. The interesting thing is it looks EXACTLY like the one I removed.

The last couple days I've learned ALOT about alternators. William Lane from here and Savvy Aviations video by Mike Busch really helped!
__________________
Paul Gray
Foley, Alabama
N729PG..... 450+ hrs
RV 7A, Lycoming 0 320 D1A, Sensenich FP propeller
pilotforfun2001@yahoo.com
VAF supporter $$$
Reply With Quote
  #72  
Old 10-14-2019, 07:47 AM
rv6ejguy's Avatar
rv6ejguy rv6ejguy is offline
 
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,425
Default

Quote:
Originally Posted by chaskuss View Post
Ross just to clarify, you're 5000 to 7000 RPM quote above is referring to alternator RPM correct?

Charlie
Yes, alternator rotor rpm.
__________________

Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, Shorai- RV6A C-GVZX flying from CYBW since 2003- 436.1 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi2.htm


Reply With Quote
  #73  
Old 10-14-2019, 09:11 AM
Sam Buchanan's Avatar
Sam Buchanan Sam Buchanan is online now
been here awhile
 
Join Date: Dec 2004
Location: North Alabama
Posts: 4,018
Default

Quote:
Originally Posted by Paul 5r4 View Post
I went with a hundred dollar unit available NOW and If I get anything close to 300 hours I think I'll be happy. The interesting thing is it looks EXACTLY like the one I removed.

The last couple days I've learned ALOT about alternators. William Lane from here and Savvy Aviations video by Mike Busch really helped!
Don't be surprised if your "cheap" alternator goes a lot further than 300 hours.

However...I usually drop the belt off the alternator pulley during condition inspection to I can spin the the pulley and check for noisy bearings. I found loose bearings one time during the past twenty years.
__________________
Sam Buchanan
1999 RV-6
1918 Fokker D.VII replica
Reply With Quote
  #74  
Old 10-14-2019, 09:29 AM
chaskuss chaskuss is offline
 
Join Date: Mar 2005
Location: SE Florida
Posts: 1,458
Default No need to make one from scratch

Quote:
Originally Posted by McStevens View Post
Where do you get a 4" alternator pulley?

I was just thinking of turning my own, maybe out of titanium
This one comes with a bushing for smaller sized alternator rotor shafts. It's also a few dollars cheaper. See

https://www.jegs.com/i/Powermaster/713/182/10002/-1

FYI, many years ago, Vans alternators came with a note stating that you could modify the pulley from the A.I.R. pump [smog pump] from a late 1970s Camero. I believe all you had to do was to open up the hole for the rotor shaft a bit. The P/N for that smog pulley is 14087007TAY. Knowing GM, that pulley was probably used on a lot more GM models. The smog pulley is 4.25" in diameter, rather than the more common 4".

Charlie

Last edited by chaskuss : 10-14-2019 at 10:28 AM. Reason: added GM pulley part number
Reply With Quote
  #75  
Old 10-14-2019, 10:22 AM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,393
Default

I'm using the 4" Summit pulley on my 70 amp Toyota Camry (ND) alternator. I chucked the pulley in my lathe and removed a bunch of metal to lighten it up, and removed the OD down to the top of the belt (it's a "deep groove", high RPM unit). With EFI and all the other goodies, I pull A lot of electrical power. To those concerned with slowing the alternator down too much at approach speeds, I can report that my auto alternator puts out everything I need. - I have seen 50 amps output at 700 engine RPM at times. That's plenty for me!

As an aside I have run this unit both with the stock internal regulator as well as converted to external regulation. No perceptible difference in performance.
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI - Flying
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
1984 L39C - flyable, available for sale
Reply With Quote
  #76  
Old 10-14-2019, 11:22 AM
Paul 5r4 Paul 5r4 is offline
 
Join Date: Oct 2006
Location: Foley, Al
Posts: 467
Default

From the information I have, primarily the alternator spec sheet I ran the numbers regarding alternator pulley size & rpm and alternator amp outputs at each. These numbers are based on my 55 Amp alt.

1. With engine RPM at 800 and a 2.75 inch alternator pulley, the alternator revolutions are about 2837. The alternator is putting out close to 40 A.

2. With engine RPM at 2400 and a 2.75 inch alternator pulley, the alternator revolutions are about 8507. The alternator is putting out 55 A.

3. With engine RPMs at 800 and a 4 inch alternator pulley, the alternator revolutions would be 1950. The alternator would be putting out about 31 A.

4. With engine RPM at 2400 and a 4 inch alternator pulley, the alternator revolutions would be 6685. The alternator would be putting out 55 A.

Sooo, if one goes to a 4" alt pulley, at close to idle power/landing phase of flight, the alternator outputs would be in my case about half. Like I've mentioned, I'm VFR only so not an issue for me. If you are IFR coming in through the clouds and have low engine/alt rpms on final approach make sure your full current demands can be met with the larger alt pulley. Yesterday when I taxied out after replacing the alternator, (old one was 60 amps), at idle power I turned everything switch in the cockpit on to see if it could handle it which it did. I know a couple years ago it would not have because I had high current draw lights. Now I'm nothing but LED's and they take almost nothing!

EDITED: I am a numbers kind of guy and can't help thinking of weird stuff sometimes. It makes perfect sense that the life of an alternator with a 2.75 pulley would be shorter. The "extra" rpms in a one hour flight are something like 109320! And for one hundred hours of flight time the extra alternator rpm are in the neighborhood of 10,932,000!!!
I figured the alternator I just removed having lived a 475 hour life turned about 237,000,000 RPM's over its life. I know useless information but interesting.
__________________
Paul Gray
Foley, Alabama
N729PG..... 450+ hrs
RV 7A, Lycoming 0 320 D1A, Sensenich FP propeller
pilotforfun2001@yahoo.com
VAF supporter $$$

Last edited by Paul 5r4 : 10-14-2019 at 11:35 AM.
Reply With Quote
  #77  
Old 10-14-2019, 12:28 PM
McStevens McStevens is offline
 
Join Date: Sep 2019
Location: Edmonds, WA
Posts: 33
Default

Thanks to everyone for the replies and links. Really appreciate the report of outputs. Full IFR panel and SDS EFI I'll need a bit of juice at all times
Reply With Quote
  #78  
Old 10-14-2019, 01:11 PM
gmcjetpilot's Avatar
gmcjetpilot gmcjetpilot is offline
 
Join Date: Jan 2005
Posts: 3,981
Default

Quote:
Originally Posted by Paul 5r4 View Post
....ran the numbers regarding alternator pulley size & rpm and alternator amp output....

1. With engine RPM at 800 and a 2.75 inch alternator pulley, the alternator revolutions are about......
Keep in mind not all ring gear pulleys are same diameter.
__________________
George
Raleigh, NC Area
RV-4, RV-7, ATP, CFII, MEI, 737/757/767
Reply With Quote
  #79  
Old 10-14-2019, 09:11 PM
WingsOnWheels WingsOnWheels is online now
 
Join Date: Mar 2009
Location: Plano, TX
Posts: 1,768
Default

I have the older small 7....something inch flywheel pulley. The numbers worked out perfect with the stock alternator pulley.

In cruise, with efis, comm, adsb, mp3, tablet, and strobes on, I only use about 8 amps. If I turn on all the lights, including the HIDs, it gets up to around 12-13.
__________________
Colin P.
RV-6A #20603
Complete 5/10/19
PP SEL / A&P
I donate every year on my B-Day (in Dec), but donated early in Sep'19.
Reply With Quote
  #80  
Old 10-29-2019, 06:57 PM
dave4754's Avatar
dave4754 dave4754 is offline
 
Join Date: Oct 2009
Location: Edson, Alberta, Canada
Posts: 474
Default And the beat goes on......

I debated over this for years. I watched as Plane and Power nosedived from top drawer to lower shelf.

I gave up and went with the B&C alternator and a Plane power regulator(ordered previously)

Expensive, say 450 Cdn i think i like the fact it is aviation oriented, the system has crowbar and overvoltage protection

A friend here had a surge go through his Cessna Skymaster and $40K later he restored the panel to service. One needs good protection.

Good luck and from what i found out, the auto alt. would work and has for many, i just chose the more expensive but i hope tested reliable B&C.

Dave
__________________
Dave Cobb
[color="Red"]=VAF=2019 Donation - and a bit extra for great work![/COLOR="blue"]
Empennage RV 7 - Tipper
Wings complete

Dynon installed and running
Fuse closer to completion, Canopy complete
AME reviewed and repaired O-320-Lyc installed
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 09:35 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.