halftrackinfo

general discussion => ALL mechanical and technical related questions => Topic started by: 8683jb on June 27, 2021, 04:37:05 PM

Title: Half-track underpowered or normal?
Post by: 8683jb on June 27, 2021, 04:37:05 PM
I've been driving my half-track on the road since I got it licensed recently. Where I live, I have hills to climb regardless of which direction I take, and it seems to me that it's a little under-powered. I know it's heavy with an engine that put out less than 150 HP when it was new, so maybe this is just the way it is. I haven't driven any other half-tracks on hills to compare it to, so I don't know if this is typical. One hill is probably near 10% grade and I have to downshift to second, and then it's to the floor to get up and over it. I know my engine is tuckered out, has a little blow-by and mediocre compressions, but it still runs great and it runs like a scalded ape on the flat! Do you guys who live in hill country have similar experiences? Is this about what I should expect of it on hills?
Title: Re: Half-track underpowered or normal?
Post by: Jesse on June 27, 2021, 06:21:49 PM
It should lug some. Definitely wont work in 4th gear. I had the same problem years ago. I had reassembled the distributer with the weights reversed. It was retarding the timing at speed and had no power, even though it ran great. That could happen to some extent if they are installed correctly and just seized up.
Title: Re: Half-track underpowered or normal?
Post by: R.E.Co. on June 27, 2021, 08:18:24 PM
Jon I have the same issue with mine. Its a dog at road speed but otherwise runs fantastic. I have a 75-80 lbs of compression in each cylinder which isn't great but is functional.
Title: Re: Half-track underpowered or normal?
Post by: 8683jb on June 28, 2021, 09:44:53 AM
Thank you guys. My lowest compression is 90 in one hole, one at 95 and the rest are a little over 100. I don't know about the centrifugal advance weights, but I expect they're working properly - as I say, nothing wrong with it on level ground; it just runs out of steam quicker than I expected on the hills. 
Title: Re: Half-track underpowered or normal?
Post by: autocar925 on June 28, 2021, 04:21:55 PM
Mine has 115 PSI, finely tuned engine.  Yours sounds normal, they don't have much power.  Slightest grade and you have to go down to 3rd. 
Title: Re: Half-track underpowered or normal?
Post by: 8683jb on June 28, 2021, 11:38:32 PM
Mine has 115 PSI, finely tuned engine.  Yours sounds normal, they don't have much power.  Slightest grade and you have to go down to 3rd.

OK, good to know. Thanks for the info.

Jon
Title: Re: Half-track underpowered or normal?
Post by: spillmk1 on June 30, 2021, 05:57:54 AM
Yours sounds normal, they don't have much power.  Slightest grade and you have to go down to 3rd.

Agree. Of course you can always speed up to a blazing 30mph or so before the hill to slightly delay the downshift.  :D

Keith
Title: Re: Half-track underpowered or normal?
Post by: Darth_Kitten on June 30, 2021, 07:48:08 PM
I'm glad you started this thread. I've been questioning the power/acceleration of my track for a while now. I guess I just have to come to terms that it is what it is.
Title: Re: Half-track underpowered or normal?
Post by: coreyelliott on June 30, 2021, 08:04:45 PM
I remember a thread on here once where someone said they could get their halftrack up to 50 after they replaced the economizer valve in the carb.  I believe ours struggles to get to 35 on flat roads with the wind at our back.  And ours is basically a complete rebuild of everything on the truck.  Maybe the economizer plunger thing is sticking or something in ours?  Not sure.

Corey
Title: Re: Half-track underpowered or normal?
Post by: 8683jb on July 01, 2021, 08:40:34 PM
Well it looks like it's performing fairly normally so I guess I just have to get my mind set that it's just the way it is and it's gonna be a little slow at times, so just plan accordingly and settle into it. I took it out on the main drag to fuel it up the other day. All downhill getting there, so nuthin' to it. Coming back, I just stayed as far to the side as I could and let traffic go around as I lumbered along in 3rd and 2nd gears. A fun drive if I didn't think about the cost to fill 'er up! Thank you guys for the responses.
Title: Re: Half-track underpowered or normal?
Post by: halftracknut on July 08, 2021, 07:21:41 PM
I have seen 35 MPH on my speedometer and every thing was wound up tight...but 50 would blow her sky high....I run her on avgas but she won't fly...
Title: Re: Half-track underpowered or normal?
Post by: Cleprechaun on July 13, 2021, 01:07:36 PM
Mine will hit 50 mph, but was a dog before I: let the extremely tight fresh motor break in. Replaced a damaged economizer in the carburetor. Let the new tight tracks get warm and loosen up. Replace all “original old stalk” ignition parts (coil, condensers, rotor & cap, points…). Kept battery well charged and well grounded (this did more than expected). Use easy to clean K&N air filter (my oil bath can is shot). Made sure all wheels and sprockets turn freely with no brake drag, if a track is jacked off the ground, you should be able to turn it by hand. No vacuum leaks at all. Tighten up the carburetor.
  All these made a difference, but the one that made the most difference was letting the tracks get warm and loose. It seems to take about 1/2 hour at 35 mph to get them warm, and then I notice it’s easy to hit 45 mph or 50 if I’m not paying attention. Of course I’m deff by then and my shoes are melted to the floor.
 
Title: Re: Half-track underpowered or normal?
Post by: 8683jb on July 13, 2021, 02:01:40 PM
Holy cow, Mike - I can't imagine 50! I gotta come up and ride around with you one of these days! I put another 20 or so dirt-road miles on mine last week and whenever it got near 35 (downhill), that was about fast enough for my cowardly blood. 20-25 was a nice speed for just enjoying the drive. And I'm sure it's easier on the half-track - as halftracknut said, 35 winds it up and makes scary noises!