7hp Subaru power washer engine

Posts: 18 · Rookie Joined: 13 May 2008 Posts: 18 Pictures: 0

I have a 7HP engine here that runs great. I was thinking about building my first off road Kart. Would this be enough power to drive on gravel logging roads. There are some good hills but if I setup the gearing will it work or is it going to be really slow?

Also does anyone have any simple to build yet cool plans for a beginner to follow? Where should I look.

Posts: 1094

jabe is building a buggy that is sooo sweet the topic is called brodys buggy build it is in this section look at that mabey you can get an idea

Posts: 1094

sorry jabo is building it

Posts: 18 · Rookie Joined: 13 May 2008 Posts: 18 Pictures: 0

that project looks great. I dont think my 7hp engine would be enough for it though. I was thinking of a smaller lighter design of some type. Im ok with no shocks.

Posts: 933

The problem with your 7 hp engine is that it is an industrial engine so not only is it underpowered it is not designed to run at low rpms so it makes power in a very small window of the rpm range. You would be alot better off selling it to some one who needs that type of engine and buying a quad or bike engine. You are going to put alot of time and effort into designing and building a car it would be ashame to do all that work and then wind up with some thing that just doesnt cut it.

Posts: 18 · Rookie Joined: 13 May 2008 Posts: 18 Pictures: 0

I was planning on using a comet Torque converter. The one I was looking at is 29:1 low 5:1 high with a 12 tooth sprocket. Am I way off base here? Isnt that what these Torque Converters are for? I was thinking of building the buggy using the motor I have and once I have the buggy working well then maybe moving up to a 13hp honda engine or maybe even a 20-24 HP industrial gas engine.

Posts: 18 · Rookie Joined: 13 May 2008 Posts: 18 Pictures: 0

for the area I want to use the buggy in I want to set it up for alot of low rpm power and a max speed of something like 40mph. I really have no need to go much faster than that. I will be on logging roads and trails 99% of the time as they are right abouve my best buddies house and I will probably build the buggy then leave it at his place to play with.

Posts: 1094

i would defiantly do some supention i dont think that that little engine will take you 40 mph but i don't know

Posts: 933

industrial engines really dont work well for buggies. They are made to run 3600 rpm for hours at a time and produce power at very specific rpm range. It is not that you cant do what you are talking about, but once you get to working on it you will find there is a lot a fabing up to get the engine to work with the suspention and make a nice cart. When you change engines that all starts over. It may sound backward but you would be alot better off getting the perfect engine and then designing a kart around it. It is just too much work to redesign and fabricate to change to a different engine after the fact. A motorcycle engine or an atv engine will work much better than any of the industrial engines out there. And no the 7 hp engine you have wont get you to 40 mph unless you strap it to your butt and jump off a cliff. Very Happy

Posts: 18 · Rookie Joined: 13 May 2008 Posts: 18 Pictures: 0

Well Im going to build the first one with the engine I have. It will teach me a great deal about the fabrication and welding either way. If its lame I will give it to my nephew to beat on.

with the 7 HP engine and a comet torq-A-verter should I go with 22'' or 25'' tires on the rear and what rear sprocket size should I use for the best drive ratio?. I like the look of the 25'' tires best.