You can handcrank an engine if the battery is dead?

[Telecolor 3007]

Question: if a car battery is dead and the car haves no magneto, only a dynamo you can start the engine by handracking it?

[Chip Chester]

Depends on if the dynamo is working. Which it probably isn't, since the battery is dead.

But yes, if there's not enough juice to start the car, it can often be started by push starting -- manual transmission (or coasting down hill before popping the clutch), pushing with another vehicle fast enough to start with automatic transmission (20-30 mph), or by using the factory-supplied crank thru the grille, engaging the special crank bolt and starting that way. (As done with my 1967 Sunbeam Alpine.) Not a pleasant task if things are not working well.

In any case, there needs to be enough voltage from somewhere to excite the coil and produce a spark. Cars with electric fuel pumps and engine computers would have that hurdle, too.

[compu_85]

Yup. Gotta have enough power to run the coil on a gasser.

On VW IDI diesels the only power required is for the fuel cutoff solenoid. In a pinch you can power this with a 9V battery.

Mercedes IDI diesels have a pneumatic / vacuum engine shutoff, they will run fine with no electricity at all. And their automatics from 1990 and earlier can be push started. Of course, if it's below 60*f outside getting them to start without glow plugs can be a big challenge.

-J

[Sandy G]

Cranking a car can be rather DANGEROUS, as it might backfire, & if your hand is too tight on the crank, or you have yr fingers around the crank the wrong way, it CAN break yr arm. That happened a LOT back in T model days. Happily, not so much any more, but I think the same thing CAN happen w/any "Crank" started engine.. Cranks have also been known to fly off, hit the starting person in the head, & kill him..

[Telecolor 3007]

There is a method that theorethically avoids hurting you hand when the engine backfires... a part of it sayes to turn the handcrank from 7 hour to 12 hour position.
But if you have a magneto you can start without a battery?

[Electronic M]

Probably not with a hand crank(I'd imagine a fraction of a turn at low speed wouldn't make enough voltage), but push starting should work fine.

One thing I've thought about is an auxillary starting battery....I often use a power inverter to help sell my wears at radio swapmeets and I'm always worried I'll drain the battery or the gas tank and be stranded. I've contemplated getting a small battery and or super-capacitor bank and wiring it to the main battery with a diode and starter relay connecting it to the main battery. The diode would allow the aux battery to always be charged, but never be discharged. The extra start relay could be used to short the diode and allow the car to start off the aux battery.... I'm surprised they don't do this from factory in modern luxury and utility vehicles.

[fixmeplease]

Old tractors turned so hard by crank I cant imagine trying it on a big engine.

[dishdude]

I looked up the only car I could possibly think of doing this with and sure enough...

https://www.youtube.com/watch?v=OQGv6RjxZkw

[bgadow]

My motorhome has a dash-mounted momentary switch which connects the deep cycle battery in the back to the start battery, in case you need a boost. I never found it to work that well since the rear battery always seemed to be too discharged when I needed the help. There is another switch which allows you to run the dash mounted radio from either of the two power sources. My rig is on an Econoline chassis which is notorious for the instrument cluster voltage regulator failing & draining the battery. My solution, cheaper than fixing the regulator, was to buy a gizmo that automatically cuts off the battery if the engine-off current draw exceeds a certain ma. Works really well; has a little key fob remote and sorta acts like a security device.

During the late 70s oil crisis my Dad & my uncle bought great big woodstoves and started cutting wood like madmen. Dad was hauling it with a Ford Courier-somewhere I have a photo, he must have had an honest ton on that poor thing! Anyway, they went to some farm auction and bought about a '49 Ford F-4 or F-5 stake body truck with the intention of using it as a hauler. The big day came to try and get it running. I remember I was given the option of riding in the Ford or in whatever pickup truck they were pulling it with; Dad told me the Ford "might blow up" which scared me out of hopping in. Wished I'd chanced it, now! I remember they drove at least a 1/2 mile but it never fired. Next thing I know the truck was gone. So much for that idea!

Oh...there was a small downhill stretch just before you got to our house. (as "hilly" as it gets here on the coastal plain) The Courier was a 5 speed. Every single time-EVERY. SINGLE. TIME-that Dad came to that hill he would cut the ignition, let it coast a bit, then flip it back to "on" and the engine would backfire, POW! POW! POW! I tell you, I don't know why that truck was completely worn out at 50k, guess those Japanese just don't know nothin' 'bout buildin' pick-em-up trucks

[Chip Chester]

Originally Posted by dishdude

I looked up the only car I could possibly think of doing this with and sure enough...

https://www.youtube.com/watch?v=OQGv6RjxZkw

The sandals make it work.

[MIPS]

In any case, there needs to be enough voltage from somewhere to excite the coil and produce a spark. Cars with electric fuel pumps and engine computers would have that hurdle, too.

My Tracker on multiple occasions had the battery run down where it could be pushed but not cranked. As long as you could get the computer to wake up and pressurize the fuel system you were golden.
But that was a little TBI 1.6l Inline 4 from Japan. I wish you the best of luck trying that on a modern V6.

[dishdude]

Originally Posted by Chip Chester

The sandals make it work.

There was plenty of crack too