Hand Crank Start V8?

[nicholastanguma]

Hello all, first post here in SS.

My fave engines are always old, tough, stone simple, and air cooled. In the world of full size truck mills this of course can only mean the air cooled diesel units from Tatra, specifically the V12 in the 111 and the subsequent V8 in the 138 and 148. The V12 was engineered to be hand crankable for emergency starts, a feat I'm not sure I quite understand considering a diesel's high comp ratio (super heavy flywheel rotation, perhaps?), but one I lust for nonetheless. I mean, any adventure driver can appreciate the ability to hand crank his engine in an emergency, right?

Anyway, I have a friend who's got access to old Tatra diesels, and he's also into wacky engine swaps, too; ergo, he's considering smashing a Tatra air cooled mill into something like an old Dodge WC Power Wagon. The hand crank feature of the V12 sure is tempting to him, but the much more compact size and lower weight of the V8 are more practical for a WC application. Anyone here know if the V8s were hand crankable like the V12s?

 

[8madjack]

Thats cool, the tatras on youtube are amazing. How do you get that stuff over here though!

 

[nicholastanguma]

How do you get that stuff over here though!

Any automobile and/or motorcycle that's 25+ years old is legal for import into the USA. Part of what my friend does for a living is restoration and modification of old autos and motos, so he's got contacts all over the world, including people in Europe and Russia that have plenty of access to old Tatras.

 

[dk8019]

https://www.youtube.com/watch?v=ao5OF7EXDcw

Very cool video of a guy hand cranking a gas powered Tatra engine. I can't see why a V8 diesel couldn't be with the right flywheel/engagement mechanism. I honestly wish more engines had this provision in equipment. Sure it adds weight etc, but it would be great to be able to fire up a diesel engine as a last resort, especially during cold weather.

 

[8madjack]

That is awesome! I love how they Advanced air-cooled technology Beyond anything I'd seen before it almost looks like to jet engines on the side with the cooling fans.

If they design trucks like they did their battle rifle those things got to be bomb-proof and pretty reliable!

Got me tripping around on YouTube looking at these big truck challenges that they have over there, crazy fun looking!

 

[tatra813]

Ive got a few tatra 813’s with v12 and a 805 with v8. Ive never know of a hand crank feature

 

[nicholastanguma]

Ive got a few tatra 813’s with v12 and a 805 with v8. Ive never know of a hand crank feature

I'm basing my hand crank info on what Wikipedia explicitly states about the V12 in the model 111; from what I understand the V12 engine designation was V910. Found here: https://en.wikipedia.org/wiki/Tatra_111#Design_and_technology

Enlarge the Wiki photo of the red 111 with the V910 engine and you can very clearly see what certainly appears to be, directly in front of the engine's main crank pulley, a stabilizing bracket for placement of a hand crank rod, like was found on the old air cooled VW engines and the Ford Model T, and on the Willys Jeep CJ3, too.

 

[Karl kostman]

Boy there almost has to be some type of device between your crank and the engine to actually be able to hand crank it isnt there? I have a 225 hp Yamaha outboard, very low compression compared to a diesel and it would take 2 stout guys to pull that engine over, a 12 cylinder diesel, I sure have my doubts
Karl

 

[nicholastanguma]

The Tatra 111's V12 engine was halved into an I6 for use in the post-WW2 Czechoslovakian military truck the Praga V3S and its civilian counterpart the Praga S5T. These two Pragas were mostly identical except for some drive drain differences like 4x4 vs 4x2, differential vs portal axles, gearbox ratios, etc. If you look closely at these images of a S5T you'll notice the front bumper and the grill behind it have little circular cutouts in them, presumably where the hand crank rod was to be inserted for emergency hand crank starting. I agree there must surely be some kind of flywheel engagement that we can't see, as obviously a diesel's comp ratio is too high to be turned over by human strength.

 

[CMPPhil]

Compression release as possible answer to your question. Apparently used on tractor and marine engine.

Cheers Phil