Need advise on upcoming project

[MonsterBengt]

I might be getting a 50's - 60's Scania truck within a year to rebuild as a swedish A- tractor, making it legal for me to drive it.

Now the restrictions for the A- tractor is simple. No rear dampers and a top speed of 40km/h. The engine itself can have unlimited power/displacement.

Now, how do I plug the transmission to go no faster than 40km/h? Or is there another way? And how much will it cost me? And to i need serious tools, or can i do it myself with some help from my dad?

Also, how do i remove the rear dampers?

And how much will a full black paint job cost me?

Thanks.

[TheSilentChamber]

Dont shift out of 1st? No suspension makes for an unpleasent -your-ass-as-sore-as-a-prison-bitch- ride. I'm sure there are other simple ways of making the truck legal... and I'm not sure if they will let you register a truck as a tractor.... and tractors arnt driven on the road.... unless what your calling a tractor is not what I'm calling a tractor... in which case... refer to question number five.

[2.2 Straight six]

im assuming he means tractor in the european way, whereby a semi is referred to as the tractor (the truck bit) and the trailer (semi trailer) but it could be tractor in an agricultural sense.

[TheSilentChamber]

A semi limited to 20mph would be quiet useless.

[curtis73]

I think it would be a blast! Unlimited power!

MonsterBengt, can you maybe help us yankees out with a photo of an example of such a tractor? I'm having a little trouble picturing it.

[MonsterBengt]

See, an A- tractor is something that only exist here. Swedish kids sometimes rebuild old volvos to make them legal at 16years of age (since you can't get a drivers license before 18). The A- tractor can look however you like, its just a rebuilt vehicle, that dont go past 40km/h and dont have rear suspension. Dont get hung up on the word Tractor.

Common looking A- tractor;

[curtis73]

So its basically a hot rod that is limited on speed so younger drivers can operate them legally? Sweet idea.

As far as the rear suspension, you could leave the existing suspension in place, but bolt or weld in a solid piece of metal where the shock used to be. That way it would use the original suspension to properly locate the axle front to rear and at the right angle, and you're just using the steel to prevent up and down motion. The stock shock mounts might need to be strengthened a little since they are only designed to take the load of the damping of the shock; not the whole shock of a bump.

For speed control, you could gear it so that maximum RPM is met at 40kph. That is not the best way since any time you're at maximum speed you're also spinning the engine really fast.

Interestingly enough, the tractor name made me think of another idea. Have you thought about using a governor for RPM control? Agricultural Tractors don't use an accelerator system, they use governors. You set the RPMs with the lever or foot pedal, and a centrifugal system senses load and adjusts fuel delivery to keep the same RPM regardless of whether or not you drop a plow in the dirt, go up a hill, or have the clutch in or out. You might be able to use an engine that comes in both applications and use a governor designed for it. That way you can set it for a certain max RPM and tune your gearing accordingly.

[Moppie]

Most European Deisel trucks are governed, it would quite easy to find a govoner for Scania engine.

Im somewhat amazed that a system exists that will let 16 year olds build and droive vechiles that weigh several tons and have unlimited horsepower, just as long as they don't go over 40km/h!!!!

Basicly it sounds like by adding the speed limiter and removing rear suspension damping, you are creating an agricultral tracter. With unlimited horsepower. And a stereo, and air conditioning..........

[2.2 Straight six]

Originally Posted by Moppie

Most European Deisel trucks are governed, it would quite easy to find a govoner for Scania engine.

it varies. here in england the national speed limit is 70mph. Mercedes-Benz trucks are geared to a maximum of 70mph. they actually can't go any faster.

[TheSilentChamber]

Here in the good ol' Texas you can have unlimited power, speed, anything you want when your 16. The old idea of what your discribing sounds kinda foolishishsish to me.

[MonsterBengt]

Originally Posted by TheSilentChamber

Here in the good ol' Texas you can have unlimited power, speed, anything you want when your 16. The old idea of what your discribing sounds kinda foolishishsish to me.

What old idea?
It's not the same thing.. You live on one of the coolest places on earth.. Your state alone are worshipped by people who drive these things.

Anyway, so curtis, there's mainly 5 things need to know now.

1. What exactly do i need?
2. What exactly do i do?
3. What do i need to do it?
4. Can me and my friend do it ourselfs?
5. How much will it cost me (aprox)?

[Moppie]

Originally Posted by 2.2 Straight six

it varies. here in england the national speed limit is 70mph. Mercedes-Benz trucks are geared to a maximum of 70mph. they actually can't go any faster.

No, they are speed limited by a throttle govoner, not gear limited.
We get the same range of trucks here, only they either remove the limiter if its an owner driver, or lower it to our limit (90kph for a truck) if they a responible fleet.
However, often the limiter is only applied when in top gear, so its possible to go one gear lower to exceed the limit for safer passing manouvers etc.

[Moppie]

Originally Posted by MonsterBengt

1. What exactly do i need?
2. What exactly do i do?
3. What do i need to do it?
4. Can me and my friend do it ourselfs?
5. How much will it cost me (aprox)?

These are all questions that can only really be answered by someone who knows the details of the truck you are buying, has expeirance working on them, and has a good background in engineering.
They would also need to know, from experiance, what level of experiance you and you friend have, and what resources you have avliable to you.

If your fathers an engineer, with time and equipment to lend you then it is quite possible you can do it yourself.
If you've done anything more than play with Lego and you only have a basic tool kit then there is no way you can do it yourself safely and properly.

[MonsterBengt]

Originally Posted by Moppie

These are all questions that can only really be answered by someone who knows the details of the truck you are buying, has expeirance working on them, and has a good background in engineering.
They would also need to know, from experiance, what level of experiance you and you friend have, and what resources you have avliable to you.

If your fathers an engineer, with time and equipment to lend you then it is quite possible you can do it yourself.
If you've done anything more than play with Lego and you only have a basic tool kit then there is no way you can do it yourself safely and properly.

My dad's been laying under a car more than in his bed in his days, so he's the one to ask. He'll do everything to help out, but im unsure about where to do it. Though the money might be a problem, if i don't get a job over the summer.

As for the truck, i don't really now what kinda Scania it is, im looking threw pics at google right now to find it. But is sure looks monster, and the exhaust pipes are huuuuge.. must be like 25ft tall

[2.2 Straight six]

Originally Posted by Moppie

No, they are speed limited by a throttle govoner, not gear limited.
We get the same range of trucks here, only they either remove the limiter if its an owner driver, or lower it to our limit (90kph for a truck) if they a responible fleet.
However, often the limiter is only applied when in top gear, so its possible to go one gear lower to exceed the limit for safer passing manouvers etc.

oh, i see. when i was looking into mercedes truck spec sheets a year ago, when doing chassis design stuff, they said the top speed was 70mph, i assumed that was the max geared speed. after all they have like 16 gears.

do you get the Actros an things over there?