# Hypothetical Question (Car Related, similar to "will the plane take off?") **URL:** \ **Category:** NYSpeed Off Topic\ **Created:** [February 17, 2011, 9:43pm UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288 "2011-02-17T21:43:14Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![boardjnky4](https://avatars.discourse-cdn.com/v4/letter/b/96bed5/32.png) [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)\ **Post date:** [February 18, 2011, 9:39am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/21 "2011-02-18T09:39:38Z")
I actually thought the answer might have been jack it up, tie it to a tree, kick out jack. If I said that I’d be called an idiot though. ---
**Author:** ![JayS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jays/32/15375_2.png) [@JayS](https://forums.speedlife.net/u/JayS)\ **Post date:** [February 18, 2011, 10:02am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/22 "2011-02-18T10:02:50Z")
> [@newman](#): > > You guys are forgetting that you have a mechanical advantage working in your favor if the truck is in high gear and depending on the rate of the final drive. A high gear is just going to make it even less likely the force of an axle and 2 tires spinning would be able to turn over the motor, since the gearing would decrease the torque being applied. And, in high gear, one revolution of the tires will barely even turn the engine over (which is why you can cruise at 60 mph and not be spinning 40000 rpm). ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [February 18, 2011, 10:17am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/23 "2011-02-18T10:17:03Z")
> [@boardjnky4](#): > > I actually thought the answer might have been jack it up, tie it to a tree, kick out jack. If I said that I’d be called an idiot though. The problem is you’d have the amount of time it takes the van to fall to let the engine turn over then kick the clutch to keep it from immediately stalling out again. I was thinking along those lines too though. You’d be better off wrapping the rope around the idler pulley and jacking up the front of the van, keeping the transmission disengaged the whole time. :tup: I say you wrap one end of the rope around the idler pulley, and tie the other end to a kudu, then set a lion loose on the kudu. It takes off running, spins the engine, you go on your way. If it doesn’t work then the lion eats the kudu and you’ve at least made peace with the lions that were about to eat you so you have another day to try things. ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [February 18, 2011, 10:20am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/24 "2011-02-18T10:20:26Z")
> [@JayS](#): > > A high gear is just going to make it even less likely the force of an axle and 2 tires spinning would be able to turn over the motor, since the gearing would decrease the torque being applied I think you need to retake physics. You are wrong. The more “overdrive” the gear, the better the mechanical advantage you have when operating the system in the “opposite” direction. > [@JayS](#): > > in high gear, one revolution of the tires will barely even turn the engine over (which is why you can cruise at 60 mph and not be spinning 40000 rpm). Right, high gear plus long rope. It’s not like you’re going to wrap it around once. ---
**Author:** ![boardjnky4](https://avatars.discourse-cdn.com/v4/letter/b/96bed5/32.png) [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)\ **Post date:** [February 18, 2011, 10:20am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/25 "2011-02-18T10:20:29Z")
lol, why not just wrangle up an elephant to push start it? Or just hop a ride on the elephant. The Rover is probably a POS anyways if the starter went bad. ---
**Author:** ![JayS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jays/32/15375_2.png) [@JayS](https://forums.speedlife.net/u/JayS)\ **Post date:** [February 18, 2011, 10:28am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/26 "2011-02-18T10:28:47Z")
> [@newman](#): > > I think you need to retake physics. You are wrong. The more “overdrive” the gear, the better the mechanical advantage you have when operating the system in the “opposite” direction. Yeah, I don’t know what I was thinking there. I still don’t think you have a chance in hell of starting it with just the inertia of the wheel and axle though. ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [February 18, 2011, 10:31am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/27 "2011-02-18T10:31:50Z")
It’s not about inertia, it’s about force and mechanical advantage. Let me run some rough numbers. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [February 18, 2011, 10:52am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/28 "2011-02-18T10:52:23Z")
JayS brain: Pull the rope without the transmission engaged so it’s easy to spin the wheels till it’s fully unwound and the wheels are spinning as fast as they can, then drop the clutch. Newman brain: Leave the clutch engaged and turn the engine over by pulling on the rope, via the wheels so that the engine is geared down. You guys have two different techniques. I think we need to solve this one via experimentation. ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [February 18, 2011, 10:54am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/29 "2011-02-18T10:54:27Z")
You want your “pullers” to gain some inertia. That’s what the clutch dump is for. They get running, then dump the clutch, then they KEEP running. There is no way that the wheel will have enough energy as a flywheel, lol. Why would you even think that. ---
**Author:** ![boardjnky4](https://avatars.discourse-cdn.com/v4/letter/b/96bed5/32.png) [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)\ **Post date:** [February 18, 2011, 10:55am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/30 "2011-02-18T10:55:50Z")
yeah I think Fry is right there…mis-communication My brain is a hybrid. pull rope without clutch engaged until it’s half-way and then pop it and use the momentum to keep turning it over a few times. ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [February 18, 2011, 10:58am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/31 "2011-02-18T10:58:46Z")
No, that’s exactly what I was talking about. ---
**Author:** ![tpgsr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tpgsr/32/7374_2.png) [@tpgsr](https://forums.speedlife.net/u/tpgsr)\ **Post date:** [February 18, 2011, 11:00am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/32 "2011-02-18T11:00:02Z")
I have a RWD manual car, Newman has a really long slackline… ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [February 18, 2011, 11:02am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/33 "2011-02-18T11:02:09Z")
Side note a low end starter is listed as 160ftlb of torque… that has to be after the mechanical advantage of the flywheel gearing, though. ---------- Post added at 02:02 PM ---------- Previous post was at 02:01 PM ---------- 100 feet, haha ---
**Author:** ![boardjnky4](https://avatars.discourse-cdn.com/v4/letter/b/96bed5/32.png) [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)\ **Post date:** [February 18, 2011, 11:02am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/34 "2011-02-18T11:02:30Z")
except that I think everyone is forgetting the way that most modern rear diffs work, you’ll need to turn both rear wheels at the same time, which makes this that much harder ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [February 18, 2011, 11:03am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/35 "2011-02-18T11:03:40Z")
if it’s an open dif you can just lock the opposite wheel ---
**Author:** ![JayS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jays/32/15375_2.png) [@JayS](https://forums.speedlife.net/u/JayS)\ **Post date:** [February 18, 2011, 11:22am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/36 "2011-02-18T11:22:45Z")
> [@newman](#): > > if it’s an open dif you can just lock the opposite wheel If you’re cruising around african safari country in a truck with an open rear diff there’s no way you’re smart enough to even attempt this. ---
**Author:** ![boardjnky4](https://avatars.discourse-cdn.com/v4/letter/b/96bed5/32.png) [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)\ **Post date:** [February 18, 2011, 11:29am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/37 "2011-02-18T11:29:49Z")
but for the sake of simplicity and the theory, an open diff car would work for testing ---
**Author:** ![somedude](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@somedude](https://forums.speedlife.net/u/somedude)\ **Post date:** [February 18, 2011, 11:41am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/38 "2011-02-18T11:41:15Z")
this will not work on a healthy engine. Someone bring a jack and rope to a meet in the spring and you can attempt to pull start my SHO. I will sit back and laugh as you throw out your back when I let out the clutch ---
**Author:** ![boxxa](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/boxxa/32/5045_2.png) [@boxxa](https://forums.speedlife.net/u/boxxa)\ **Post date:** [February 18, 2011, 11:43am UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/39 "2011-02-18T11:43:53Z")
Ya the only way it would work would be having another sizable car pull the rope and have the rope me a type of high tension metal wire. You need to roll a car quite a bit to get it to turn over so like JayS said, there is way to much power needed to get the wheels turning to cause the engine to turn over, esp on a large engine like a safari car. ---
**Author:** ![JayS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jays/32/15375_2.png) [@JayS](https://forums.speedlife.net/u/JayS)\ **Post date:** [February 18, 2011, 12:02pm UTC](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288/40 "2011-02-18T12:02:30Z")
I just keep thinking about all the times I’ve pop started cars and how much braking force an engine has even with 3000 lbs of car trying to turn it over. A few hundred pounds of people are going to get stopped dead. [Previous page](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288.md?page=1) [Next page](https://forums.speedlife.net/t/hypothetical-question-car-related-similar-to-will-the-plane-take-off/209288.md?page=3)