ZF 4HP22 bolt pattern

dokatd · Post by **dokatd** » Sun Feb 01, 2009 8:15 pm

The engineers didnt have any HP in mind when they built the drive train, they had torque in mind. Torque break stuff, HP just makes stuff go fast (Generalized statement). Assuming you can acheive 150HP, it would still be far less load on the drive train than EI's crawler setup. Regardless, the power gains will only be realized on the road due to the behavior of turbos.

Erik712m · Post by **Erik712m** » Sun Feb 01, 2009 8:43 pm

I'm pretty sure HP is the problem? I think really they said 110-140HP Max. Remember it is for the most part. a solid peace from the front to the rear no yoke no flex lots of vibration.

I also believe the crawler setup broke a few things as well?

Jim LaGuardia · Post by **Jim LaGuardia** » Sun Feb 01, 2009 9:46 pm

As a tranny guy I'll put in a few words

You will lose output torque power using an auto trans. I know, bold statement but take in mind that all torque converters are " fluid couplings". For the most part you will only be able to use 40 to 60% of relative torque available due to the inefficiency of the fluid coupling. If using a lock up converter you will have to add some safety items , like brake switch activated release.
I am sure it can be done, but at what cost, and is it a), an improvement, or b), reversible?
Have fun with it and please post pictures as you proceed

dokatd · Post by **dokatd** » Sun Feb 01, 2009 9:54 pm

Thats a common misconception. Of course HP cannot live without Torque and torque cannot live without HP. But they do exist in ratios. driving down the highway you are using primarily HP with low Torque numbers. While offroad you are using Torque with low HP numbers.

Saying a component cannot handle 150HP means nothing unless there is a torque value to go with it. If you had said the drive train cannot handle more than 10,000 Ft/lbs of torque at the wheels, that would make more sense.

What Im saying, is that if you were to use 150HP while accelerating, your torque numbers are being reduced as your speed increases. These torque numbers in High range are far less than what you could ever create in low range. HP if it could exist by itself could never break a component on any vehicle. That being said, you could have 2000HP in your pinz as long as the torque value remains stock. On the other hand, you could break every part of your pinz if you had huge torque numbers and only 1 HP

The basic function of a transmission is to convert your Torque and HP from Loads of torque and low HP to Loads of HP and low torque.

High torque low HP means low speeds
High HP and low Torque means High speed.

Anyways, These are again all general statements. Its really not so cut and dry. The bottom line is, A general statement saying a drivetrain cannot handle X amount of HP is valueless. It must be backed by a torque number.

Hope this helps.

dokatd · Post by **dokatd** » Sun Feb 01, 2009 10:04 pm

I will be using a lock up torque converter. Not sure what the lock up RPM will be yet. But a brake switch/interlock is not required. I agree about the torque loss, but It tends to not be an issue. In rock crawling, the auto torque converter makes for a more drivable vehicle even with smaller crawl ratios. The torque converter in theory can as much as double the effective crawl ratio untill your converter locks up. This has been debated in the offroad world, but Its something I have experianced first hand. Of course I dont have numbers to back up the theoretical 2X number. This effect is also why you can get away with High range 1 gears numbers far from the granny 5.33

But I assume you know all this Jim so thats the end of that.

Jimm391730 · Post by **Jimm391730** » Mon Feb 02, 2009 8:43 pm

The main drive shaft in a Pinz is large, is heavy, and is not supported "well" compared to most "American Metal" drive shafts. On top of that, the Pinz drive shaft spins at twice the rpms for the same speed as most pickups. So although I agree that the torque is lower at speed, my personal opinion is that 60-70 is about the fastest that I want to drive a Pinz, even with both of mine havng modfied "lighened" and balanced shafts.

The drive train really does have a speed limit, and it is limited by the shafts.

BTW, even with Jim L's 2.7l motor and EFI, I can barely get effective use from the TD tranny's 0.75:1 ratio overdrive. For me, this gives me exactly half the rpm's compared to mph (3000 rpm = 60 mph). I"d hate to even consider 0.69:1!

Jim Mettler
712W, 710M

Erik712m · Post by **Erik712m** » Mon Feb 02, 2009 8:53 pm

Jimm391730 wrote:The main drive shaft in a Pinz is large, is heavy, and is not supported "well" compared to most "American Metal" drive shafts. On top of that, the Pinz drive shaft spins at twice the rpms for the same speed as most pickups. So although I agree that the torque is lower at speed, my personal opinion is that 60-70 is about the fastest that I want to drive a Pinz, even with both of mine havng modfied "lighened" and balanced shafts.

The drive train really does have a speed limit, and it is limited by the shafts.

BTW, even with Jim L's 2.7l motor and EFI, I can barely get effective use from the TD tranny's 0.75:1 ratio overdrive. For me, this gives me exactly half the rpm's compared to mph (3000 rpm = 60 mph). I"d hate to even consider 0.69:1!

Doesn't this make my comment correct? On up not torque.

Jim Mettler
712W, 710M

dokatd · Post by **dokatd** » Mon Feb 02, 2009 9:55 pm

Don't get me wrong, I don't intend on driving at 80mph. I simply stated the numbers could support 80. As aposed to 65ish. And even then I will need more output than a stock engine to do it. Rest assured I know the issues I am facing. Pinz aren't as unique as you guys like to think. All the components have been used in one shape or form in other vehicles for a long time. This just happens to be a case of lots of odd components in one vehicle. You guys are trying to make it harder than it really is.

Time will tell.

Profpinz · Post by **Profpinz** » Mon Feb 02, 2009 11:59 pm

All the components have been used in one shape or form in other vehicles for a long time

Hmmm....I'II disagree with that to an extent.

Yes, things like the gearbox are a derivative of ZF S5 OEM box and the alternator and starter motor etc do use standard Bosch components, and the diffs use standard bearing and seals etc, etc, but SDP were well known in the 60 and 70's for doing and making there own things.

Unlike most US or even other European manufactures back then, they designed and built (or had built) EVERYTHING to their own specific engineering requirements.
They built their own motor because they believed no other manufacturer had in their range a unit that fullfilled the vehicle requirements, they even used one-off, non standard wheels because they wanted a larger wheel stud PCD to spread the lateral load.
Yes things changed slightly with TD range (standard off the shelf motor, auto, even door handles and mirror)

Read books like PUCH by Egon Rudolf and PUCH-Automobile 1900-1990 by Friedrich Ehn and you'll get an appreciation of how unique SDP and the engineers who worked there were.

If you can find another vehicle that uses the 710/712 air-cooled motor (or even that same cylinder....discounting the defunct SDP 720A) differential assembly (crown wheel, pinions, differential bearing cups) axles, axle casings, drop boxes, handbrake disks, backbone etc, etc, even door handles then be my guest!

With the Pinzgauer (and Haflinger), you've got to get your head around the fact that that they built "old school"...everything was done on drawing boards and not to a cost....No CAD component libraries from Borg or ZF or Dana or Delco, ASM, Fortuna etc etc, that engineers can use to "Lego-up" an assembly.
Cost wasn't that important to SDP....Function and quality was everything.

Hey guess what, I'm sounding like an SDP enthusiast!

You guys are trying to make it harder than it really is.....Time will tell.

As I said previously nothing is impossible and problems like fitting an auto are there to be solved, but unless your totally familiar with every Pinzgauer assembly and components, then, I'd be wary of thinking it's like any other vehicle.

Anyway, that's my two cents worth and I look forward to seeing pictures and details of the completed project!

BTW...Meet the SDP design/engineering team:

dokatd · Post by **dokatd** » Tue Feb 03, 2009 10:52 am

Sadly once again my words have been twisted. I did not say that you will find an air cooled pinz motor being used else where. I didn't say in anyway that you can find any part of a pinz on any other vehicle.

I said with more clarification, all the components you find on a pinz are not unique in that they have all been done before by other manufacturers. Not all on one vehicle, but scattered across the great history of vehicles.

Diffs and swing axles have been done by companies like MANN and tatra

VW perfected the air cooled automotive engine before the pinz was around
Ford chevy and numerous others used divorced t-cases back in the 50's and 60's

The point being, just because you build all your parts to your own spec and have a total lack of compatability with another vehicle does not make yours unique. Nor does it change the laws of pysics and the dynamic way in which your parts work.

If you want to argue that the tranny has a totaly unique bolt pattern, or that no other door handle will simply fall into place, be my guest. And if I am not aware of the cold fusion device in the engine that makes it unique. Please inform me. But I have a clear understanding of every part of the pinz and I'm here to tell you, it's not unique sitting in pieces on the garage floor. It's only unique once it's all put in one rolling vehicle.

Tatra was building these in 1960. Minus the extra front axle its just an oversized Pinz. same type of axles, same drivetrain style etc. Dont fool yourself, the pinz is just a run of the mill specialized military vehicle.

Need I go on

Profpinz · Post by **Profpinz** » Tue Feb 03, 2009 3:33 pm

said with more clarification, all the components you find on a pinz are not unique in that they have all been done before by other manufacturers. Not all on one vehicle, but scattered across the great history of vehicles.

I agree when you bring the historical aspect into play, and if I misintrepreted your words I apologise, but I thought we were talking about the intricacies of fitting a 4HP22 to a 710/712 rather than generic design mechanisms/assemblies/concepts etc.

Interestingly the frameless central tubular chassis (so-called "backbone chassis") with fully independent suspension swing axles, and rear-mounted air-cooled flat engine was invented by Hans Ledwinka when he worked for Tatra as chief design engineer between 1921 and 1937

Together with his son Erich, who took over the chief designer position at Tatra, Ledwinka designed the Tatra streamlined models Tatra 77, 87, 97, all with rear air-cooled engines.

Hans worked for Steyr in the early 1900's and his son Erich designed and developed the Haflinger and Pinzgauer when he worked for Steyr Puch later in that century.

VW perfected the air cooled automotive engine before the pinz was around

An interesting extract from Wikipedia;

Ledwinka's concepts were copied by Ferdinand Porsche, who knew Ledwinka personally and exchanged ideas with him. Tatra sued Volkswagen about the breaches of the similarities in the Volkswagen design which has been virtually copying Tatra T97. The lawsuit vanished as the Nazi Germany invaded Czechoslovakia in 1938, and Hitler ordered the production of Tatra T97 to be halted. Only 500 cars were produced.
Porsche's successors later had to acknowledge the influence of Ledwinka's Tatra models on the Porsche-designed Kdf-Wagen of 1938 (later known as the VW Beetle), and a new post-war lawsuit resulted in a DM3,000,000 settlement paid by Volkswagen to Ringhoffer-Tatra.

So I guess all the concepts and "unique parts" originated from one bloke whose son then designed the Haflinger and Pinzgauer.

dokatd · Post by **dokatd** » Tue Feb 03, 2009 4:44 pm

No apology required, I just wanted to make sure we understood each other. The only thing I was hopeing to gather from this post was to rule out anything anyone has already done. I just didnt want to reinvent the wheel if something was sitting out there. Seeing as how it was a ZF transmission, and typically the tranny manufacturer makes the bell housing and the engine is made to suit, I just wanted to rule the options out. I think we ruled this out in the first couple of posts. Then we strayed from the actual topics to discuss power requirements min or max etc. So I guess it was confusing for everyone. And considering the 4HP22 has options for 3rd or Over drive, 3rd being a 1:1 ratio which is what the 712 has to begin with, power is not at the top of my list right now. And I really dont have the desire to give a lesson on auto transmissions.

Thank you Profpinz for your input. And thanks for the history lessons. I like knowing the history of the things I drive.

Profpinz · Post by **Profpinz** » Tue Feb 03, 2009 5:13 pm

No problems, it's been an interesting thread!
SDP certainly have an interesting design and manufacturing history that has intrigued me for years.

Good luck with your future Pinzgauer (and Land Rover) projects.

Erik712m · Post by **Erik712m** » Tue Feb 03, 2009 5:51 pm

Peter, I think Hans may have stole Some of the Designs From the Flinstone mobile.

Dokatd, I think this was a great topic. Even if you didn't want to give a lesson.

dokatd · Post by **dokatd** » Tue Feb 03, 2009 5:58 pm

The flinstone mobile is based off a dual symetrical torque tube chassis. With options like 4 and as much as 8 foot drive. And it's inherent stability is due to the low cg created by bias cut 22" stone wheels. Truely a design far ahead of it's time.