Hupmobile Model 20 Serial Number

[Guest Mochet]

I understand there are two serial numbers on the Hupmobile Model 20: a plate under the magneto switch and stamped near the transmission. Should these be the same number?

Phil

[trimacar]

The two numbers on my 1910 are right next to each other, at the top of the flanges connecting engine and transmission (I.e. one on engine flange and another on transmission flange).

No, they probably won't match, but should be in the same general number range.....the whole "matching numbers" is a fairly recent game.....I think my numbers are within 100 or so of each other....and then there's the serial number on the dash plate if you have it, and again, it probably won't match the other two numbers...

It could be they stamped the engine number at some time around magneto, don't know...

[Guest Mochet]

Thanks. I'm looking at a 1911 Model 20 next week. It doesn't run, but have you any suggestions for checking the drive train, etc.? I know transmission and differential gears are sometimes chewed up. Was there originally a cover under the engine?

Phil

[trimacar]

If it doesn't run, then it's tough to check the drive train, since everything is enclosed. If they'd let you do it, I'd jack up the rear end and see if differential is working by turning wheels, and remove four bolts on transmission cover and inspect gears.

Yes, there was a belly pan on these cars, although you won't see very many of them. I believe that they were removed and left off pretty soon, as you had to access the bottom of the engine to drain the oil after each run. There's a standpipe on each of the two valves, and you open and drain until no more oil comes out, since the oiling system is gravity and pass-through. I have an original and a repro pan for mine, both hanging on the wall...

Good luck with inspection, they're fun little cars, with the main problem being no middle gear (just low and high), so hills are fun....they're 35 mph cars all day long, although I've had mine a little faster it's not comfortable.....

[Guest Edgar Bowen]

There are two sets of numbers on Hupp 20s, one on the gearbox carrying cross member of the chassis, corresponding with dash board name plate. The other is the number on the power unit including engine and gearbox. These two numbers are never the same. The engine number is stamped on the flanges that fix engine to gearbox, the crankshaft, connecting rods, side plate under the magneto and the clutch drum. It is fairly important to have matching crankshaft and clutch drum to get a tight fit. You may have trouble fitting non matching side plate and crankcase together as the bolt holes were matched at their original assembly.

[Guest Edgar Bowen]

Regarding the engine belly pan, I made mine up and find it useful for keeping dust from the front wheels out of the engine bay. It is also very handy for checking crankcase oil levels and draining the oil from the crankcase. I carry a sardine tin with me which fits nicely under the drain cocks to catch the excess oil from the total loss system. I check this every 1½ - 2 hours driving time. I change the engine oil every 10 hours driving time. Then I simply unscrew the cocks in the crankcase, catch the oil in the pan and drain it off from a single bung at the front of the pan. It helps to have a box of facial tissues on hand to wipe up the oily pan at the conclusion. The crankcase only holds 1 litre of oil.