Hair brained project ideas. Thoughts before building?

[Kansaskart]

I had a lot of crazy ideas as a kid. Now that im older I have the fabrication skills to bring these ideas to life. One of my dreams was a 4 engine kart with an engine on each wheel. Someone has done that on youtube and it was exciting to see and also a relief as seeing it operate was enough to satisfy my curiosity. Not to mention time and money!

At any rate what do think would happen, asides mechanical failures that could be addressed, on the idea of a twin rear engine kart but each engine would have a diffrent gear ratio? In other words start with a fast 0 to 30 or so with a cvt, lay off that throttle and hit the other engine which would have a ridicuously small axle sprocket.

We have some long straights out here and could test it. Im sure it wouldnt work as well as it sounds but thoughts? Be pretty wild to see a stock 212 hitting 70 or better lol if it works.

Probably better and easier options, like why not just buy a yamaha kart race engine. Its just the novelty of it and the experiment part. Im a fast fab guy, I could throw it together in no time and I already have plans to add a dual 212 kart to my lineup anyway so it wouldnt be a waste.

Worth a try? Stupid? With the advent of the net I feel much more comfortable with the ideas I come up with seeing what other people do. For instance, briggs powered motorcycles lol!

Also if its something im really gona do I used to think not to say anything, which would be a gd idea if you wanted to capitalize it on youtube etc, but now im like go ahead and write about it cause I got the timestamp now to show yeah thats my baby. This probably isnt one of those times but then I coulda been writing about a 4 engine kart 40 years ago had we the net. Granted so could others im sure.

 

[Mastercrafter]

Briggs and Strattonson.
Hardly dangerson

 

[Bbqjoe]

Do it!!!

 

[tazmannusa]

I think the friction from the driven and belt on the engine not in use would be the killer

 

[KartFab]

Also if its something im really gona do I used to think not to say anything, which would be a gd idea if you wanted to capitalize it on youtube etc, but now im like go ahead and write about it cause I got the timestamp now to show yeah thats my baby.

lots of ideas never come to fruition because of the high barrier to entry: work ethic.

Lots of ideas that come to fruition dont ever end up on youtube because of the much higher barrier to entry, freaking PITA to film stuff while working on it, (takes 3x longer to do when filming), then on top of that edit it into something someone would enjoy watching (e.g. viewers with the attention span of a chipmunk on speed with ADD).

I've also thought about that scenario you are talking about(2 engine kart with two different ratios), and so have many others before you.

The problem lies in the fact that if you do it with torque converters, the belt on the one geared for low speed will be engaged in overdrive when you need to switch to the other one. The driven units will always be spinning, which isnt an issue, the issue is the low speed engine will stay engaged, even if you back off the throttle at high speed. So you have one engine braking under compression at high rpms fighting the other engine trying to engage at low rpms.

It would be interesting to see you try, and not listen to the nay sayers (me) because naysayers can be proven wrong.

Also, i have also thought about doing it with centrifugal clutches. The bell housing part of the clutch can spin independently of the engine shaft, right? so can you get the outside part of the clutch to spin without the inside weights touching it? You can do it with your hand, so why not while connected to a chain but at higher rpms? hint hint. maybe you could pull it off with centrifugal clutches. maybe a 60-72t axle sprocket and then a 36 t axle sprocket or smaller.

So going back to work ethic and filming... someone else 'stealing' your idea, no matter how good it seems to you, is really a silly way to think because you literally have done nothing with it, and you can count on nobody else doing anything with it because people are lazy and don't film stuff.

Its like saying, oh hey ill run for president, but you never do, then someone runs for president, and you say, oh yeah that was totally gunna be me, it was my idea. 99.9999% of the battle is actually doing it. So do it! That way the 99.99999999999999999999999999999999999999999% of us that wont do it can sit back and be like oh yeah that was our idea, or cool i totally would have done that.

 

[ezcome-ezgo]

Hair-brained. Brain made of hair? Them manual clutches could mayeb also be useful in this application.

 

[Kansaskart]

Thanks for the input. I was leaning more towards clutches after I gave it some thought as I wasnt sure how the cvt would react.

Also you're right about the work ethic thing. I did just bring home a kart recently with a trashed rear end. I cut it off and completely redid it and have been driving it a lot.

Next up is finishing my offroad kart that I got cheap cause they hit a tree and ripped the right tire off basically. Its on the surgery table right now.

Then im picking a custom project which I already drew plans.

You know, getting back on topic, I do have an old frame that just needs tires and I have a couple new 212s in the corner in boxes still. Im thinking about a landspeed vehicle vid I seen. Maybe have a test run. I already know clutches will spin and wont be an issue. I could just put 1 engine on it and have my buddy tow me with the 4 wheeler to 35 or so and see what happens. I already have the idea for the rope realease im not gona be holding it.

I also like the criticism. I always do better when im told ill never do it. I will try it out, try to get some pics and put it in the builds section or wherever appropriate. Thanks.

---------- Post added at 04:55 PM ---------- Previous post was at 04:40 PM ----------

And before anyone goes berzerk over the rope idea lets just say i've spent most of my life in high risk professions, climbing around on buildings, moving chunks of steel around the size of a bus to lofty areas, im capable. Lol. Probably be one of the few here that will wear a helmet, goggles, gloves and jeans when jacking around with the unknown. I got more than my fair share regarding scars of stupidity.

 

[anderkart]

You could allow that axle sprocket to freewheel, if it's hub had a one-way bearing or sprag assembly...

You could use one of these wheel hubs as your sprocket hub: http://www.mikeclementsracing.com/accessories.html

 

[Kansaskart]

Interesting. Thanks! Probably stick with the experimental 1 engine idea for now, just to see how it would perform taking off at 35 or so, theres no question about how the first engine would perform. Then I could make a final product if I thought it was worthwhile. First things first, better brakes and dont need a chunk of flywheel in my head. Looking mostly stock otherwise, basic performance kit, no govenor.

 

[Scout]

I was going to say you'd need a manual clutch on the low speed motor, the centrifugal clutch will stay engaged and the low speed motor with just rob power and slow your top end.

I can think of a couple ways to build a rope release, I wonder what you have in mind?

 

[Kansaskart]

Im gona argue with you and say that it wont stay engaged. Hopefully we find out. The inner is diven by the engine and will collapse when the rpms lower, same as they would if there were only one engine. I suppose there could be a few second lag. If it were a problem ill make it work. Im not doing anything extravagant with the rope. It doesnt take anything to pull a kart. Pair of visegrips or something its not like I need both hands on the wheel at 30mph.

 

[Scout]

Im gona argue with you and say that it wont stay engaged. Hopefully we find out. The inner is diven by the engine and will collapse when the rpms lower, same as they would if there were only one engine. I suppose there could be a few second lag. If it were a problem ill make it work. Im not doing anything extravagant with the rope. It doesnt take anything to pull a kart. Pair of visegrips or something its not like I need both hands on the wheel at 30mph.

If that was the case, then the inner would disengage when you let off the throttle. Once it's up to speed and engaged, it won't disengage until both axle and engine slow, and since you aren't trying to slow, it won't disengage from the engine. It would be a big parasitic drag and possibly overspeed the engine. But we'll see, won't we?

As far as the rope, I was thinking a piece of metal in a C shape with a hole drilled in top and bottom, then use a pin to hold the rope, pull pin to release.

 

[Kansaskart]

If that was the case, then the inner would disengage when you let off the throttle. Once it's up to speed and engaged, it won't disengage until both axle and engine slow, and since you aren't trying to slow, it won't disengage from the engine. It would be a big parasitic drag and possibly overspeed the engine. But we'll see, won't we?

As far as the rope, I was thinking a piece of metal in a C shape with a hole drilled in top and bottom, then use a pin to hold the rope, pull pin to release.

You could be right, im not gona sit here and claim im sure because im not. If so it would only be a hurdle, not an impossibility. Your rope idea is ok but since the rope would be pulled it might be hard to pull the pin. Thats really the least of my worries.

I wish I didnt have the other karts to finish now lol. I've heen trying to stay focused on what I already have seems only way I can get things done.

Im thinking test one engine with small sprocket to see if the rest of this is even worth doing. Right now I dont have any karts suitable for twin engines all my frames are small, on purpose. A 212 takes up the entire rear on them. My preferrence is small light frames with good ground clearance.

Im sure with the small sprocket theres gona be a big diminishing return thing going on, not like im expecting a 2" sprocket to go proportionally faster.

Starting to sound like a good bench experiment if the first test passes. Just do an axle mock up with with a couple engines and experiment with it. Wouldnt be a waste of money if it dont work id still have 2 good engines.

Question is what speed would make this worthwhile? Thats a personal preference, for me im thinking anything over 60mph with stock engines otherwise my as well just go with a fast single.

So, finish what I got then maybe this problem is I got another special idea stirring for awhile and im not even going to talk about it I already know ill get "that wont work" comments and im gona do it anyway.

---------- Post added at 07:34 AM ---------- Previous post was at 07:23 AM ----------

Meanwhile if you, or anyone else, want to try this and report results please feel free! Lol.

 

[Newtoy]

One way round it is an over run clutch on your output. Like a bicycle. 1st engine could sieze up or be left at full throttle and it would not matter. Down side, no engine braking on low speed engine.

This needs a bit more thought but just throughing an occurring thought out there with a over run clutch on the driven side of the high speed engine also you could use both engines to accelerate through the low speed gearing and then when it goes into over rev instead of dragging it just free runs the drive an leaves the other engine free to continue accelerating on its own. No engine braking at all. Enter at your own risk hehehe

 

[Kansaskart]

One way round it is an over run clutch on your output. Like a bicycle. 1st engine could sieze up or be left at full throttle and it would not matter. Down side, no engine braking on low speed engine.

This needs a bit more thought but just throughing an occurring thought out there with a over run clutch on the driven side also you could use both engines the accelerate through the low speed gearing and then when it goes into over rev instead of dragging it just free runs the drive an leaves the other engine free to continue accelerating on its own.

Thats really weird as the cyclists were having a run out here just yesterday and when they went by I had flashbacks and immediately thought just what you said. I need to get some other projects done this is all thinking ahead. Id still like to just try a single engine from 35mph to see what happens before wasting a bunch of time with it.

 

[Scout]

A single engine will get you to 35 easy, but going beyond that will take more horsepower. I wish I could tell you how much you'd need to double that.