Jump to content

Model 20 Electric Starter?


Recommended Posts

Has anyone installed an electric starter motor on a Model 20 Hupp? The front-mounted flywheel seems accessible. The current issue of the HCCA Gazette has some ideas for a starter-generator setup on a 1904 Cadillac and 1912 Buick.

 

Phil

Link to post
Share on other sites

There's a gentleman in Maryland who tours a heavily modified Model 20, and I know he has a starter, among other things.  One thing he did was lighten the flywheel considerably, says it gives the car more pep.  I'll see if I can find his name for you.

 

I know there are other reasons for adding a starter, a friend of mine has a bad shoulder so is adding one to an early T.  That said, a Hupp is pretty darn easy to crank!

Link to post
Share on other sites

Thanks, David. Yes, it's easy to crank if it starts the first or second time. The nice thing about a belt-drive starter is that it can be easily removed should the car become easy to start manually.

 

My though is to use a 12v starter motor with no generator... if I can figure out how to attach it to the Hupp.

 

Phil

Link to post
Share on other sites
  • 2 weeks later...
13 minutes ago, MochetVelo said:

Could anyone tell me the maximum rpm of the Hupmobile 20 engine? This information will allow me to determine the starter pulley diameter.

 

Phil

I'm not clear why you'd need to know the "maximum" rpm.  An internal combustion engine needs to turn 50 to 100 rpm for reliable starting, and that's the speed range you should work toward.....

Link to post
Share on other sites

The starter/generator would be connected to the flywheel by a belt, so it turns along with the engine. The goal is to keep the generator speed under 12,000 rpm. Therefore, the maximum engine speed will determine the diameter of the starter/generator pulley.

 

Phil

Link to post
Share on other sites

I see, said the blind man to his deaf wife on the disconnected telephone....

 

Well, let's figure it mathematically. 

 

At 40 mph, you're traveling 0.67 mile per minute, or 3538 feet per minute.  30 inch tire, or 2.5 feet, circumference is 7.85 feet. 

3538 feet/7.85 feet per revolution = 451 rpm at the axle.

 

If it's a 3.5 ratio rear end ( I think Hupp offered a 3.5 and a 4), then 3.5 x 451 = 1578 rpm at 40 mph, which I'm saying is about as fast as one would drive a Model 20.

Link to post
Share on other sites

Thanks for the math, David. The author of the recent HCCA Gazette article on starter installation calculated his 1912 4-cyl. Buick at 2000 rpm and 1904 single-cylinder Cadillac at 1100, so 1578 sounds about right for the Hupp.

 

I filled in the numbers on this page (rounding rpm up to 1600), and came up with 2-inches as the pulley size for the starter.

 

Phil

Edited by MochetVelo (see edit history)
Link to post
Share on other sites

Wow, a 2 inch pulley isn't going to give much friction surface belt contact , it'll have to be tight and/or lots of belt dressing!  Of course, I guess you could put on a belt as wide as the flywheel.....

 

I think that rpm sounds about right, too....I've had my car over 40 mph with a 3.5 rear end, and that's as fast as one would want to spin that little motor....and if it had the 4.0 hill climbing rear end, then 35 mph or less might be max....

Link to post
Share on other sites

I got my information from the informative article by Howard Hodson in the March/April 2018 issue of The Horseless Carriage Gazette.  He has used this belt-to-flywheel setup successfully on his 1904 and 1914 cars. His 1904 Cadillac uses a 1.9" diam. pulley to a 20.5" flywheel via a poly v-belt. This belt is about 1/8" thick with 5 ribs on it (like a serpentine belt used on a modern car). The author states that the belt slippage is not a problem with proper belt tension.

 

Phil

Link to post
Share on other sites
1 hour ago, MochetVelo said:

I got my information from the informative article by Howard Hodson in the March/April 2018 issue of The Horseless Carriage Gazette.  He has used this belt-to-flywheel setup successfully on his 1904 and 1914 cars. His 1904 Cadillac uses a 1.9" diam. pulley to a 20.5" flywheel via a poly v-belt. This belt is about 1/8" thick with 5 ribs on it (like a serpentine belt used on a modern car). The author states that the belt slippage is not a problem with proper belt tension.

 

Phil

Excellent.  I'm all for modifications that can easily be reversed, If one were talking about machining the flywheel and shrinking a ring gear on same, I'd be more vocal, but a surface belt is, in the sense of originality, reversible.....

Link to post
Share on other sites

I had to fabricate a tension idler to get the required surface of a 2" start/gen pulley to function properly, It was a few years ago but as I remember the wrap was approximately around 200-250 degrees on the generator . I have since sold the car, but it has popped up on several tours, I assume still functioning. Phil, it was also a poly serpentine belt.    Bob

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...