what is the difference between a airplane engine and a car engine?? because i have some car engines i would like to use on my airboat project, but is that ok to do??? i would really appreciate some input

The main difference is the method of starting the engine, most Car engines have a pullstart, while some have an onboard electric start. Airplane engines can be started in two ways, with a flip of the prop and a glow igniter, or with a seperate starting motor and a glow igniter. With aircraft there are also no clutches.

thank you for the reply. but is it ok to use that on a air boat?? if i want to start it with a pull starter, and could i put a prop on it with the clutch off???

definately possible, I don't see anything wrong with it. you have to just be careful with the pullstarter around the prop. A nice alternative to lugging around a battery for the starter. What do you have for an engine?

i have got a torq.16 with a stinger pipe, and a brand new o.s.max .12cv with tuned pipe. what do you think bsmooth. and i have some boost bottles that i got to work right. plus i would like to try a super charger some time.

well according to O.S. .12cv specs shown on thier webpage, I estimate you should run about a 7-6" daimeter prop with 4-5" of pitch (7x4 or 6x5) the only thing I forsee as a slight problem is the manifolds for those engines.i might look a bit wierd having the tuned pipe out infront of the engine mount, but it'll work. The torq .16 is from duratrax right? I asume you got the O.S. to replace it? If this is your first Airboat, I would reccomend using your OLD engine first, as airboats are prone to tipping over and getting the engine wet. but that is up to you.

thanx man, i will give it a shot and let you know.

The only problem you may run into with using a car/truck engine is prop clearance between the prop blade and the carb. I have a CV.12 that I tried to put an airprop on, and the prop would hit the carb housing. Turning the carb around made no difference. It seems that the carbs used on the car engines is usually taller than a carb used for airplanes, which makes it closer to where the prop blade would be. Beware of this .

Another problem i could potentially see is that the bearings or bushings on your car engine may wear out very quickly, airplane engines are designed with the lateral force of the prop(whether push or pull) in mind. I don't know if car engines have the same design taken into consideration.

Same type of bearings are used in these engines so should not be a problem.

Actually, the bearings in the car engines should last longer BECAUSE there is only a lateral load and a minor side load.

Airplane engines DO produce a thrust (side) load to the bearing and less of a lateral load. It would be great to see a mfg design an engine with both types of bearings installed to take on both types of loads.

The reason bearings in car engines do not last long is because of the rpms they are subjected to and possible lack of lubrication to the bearing itself. That and all the dirt that gets picked up and worked into the bearing balls themselves. 'Sealed' Bearings ??......[sm=lol.gif]