Titan R3 vs. GXH50 and a couple others...

conradcliff · #1 11-06-2008, 11:03 PM

So, I've pretty much figured out what I want to do and I'm just about completely sold on the Honda GXH50 but before I committed to it I wanted to get your opinions about what engine you suggest.

My first choice currently is the Honda GXH50. I think it will work very well for my purposes but if I can get the same or more power with the same or better reliability for a cheaper price I may change my mind.

From the pictures on thatsdax it doesn't look like I can simply attach a sprocket to a solid shaft on that engine (which is what my current build design calls for). Is there a way to do this? Also, if there isn't can I simply get a 10 tooth clutch bell for the attached clutch(I'm thinking no)? I do like that the Titan is slightly cheaper and has a gas tank already.

Browsing around I came across these 49cc engines from bikeparts.com, I couldn't find any useful info on their site about them though. Does anyone have any experience with these? What kind of power and reliability can one expect from them?
The first one looks pretty kick @$$ don't you think?

Anyway, I am so close that I can almost taste the bugs in my teeth!

I just can't wait to get this project off the drawing board!

Thanks again to everyone that has helped me out so far! And thanks for any more info you guys can provide!

**Dan** · #2 11-06-2008, 11:32 PM

From researching, the Honda GX50 turns very fast so has to be reduced to work for a MB b4 a clutch will work. can be done but adds cost. basically one would have to buy a gearbox or build one. And the GX has a very short drive shaft. A grubee gear box will work and the only box I have found on paper that will work. I am in no way an expert, but thats what I have found out so far.

Also a 4stroke will need wider then normal peddles.

**Dan** · #3 11-06-2008, 11:41 PM

I have to ask for permission to post, but have some information from a manufacturer on how to work with a GX50. I had the same questions.

conradcliff · #4 11-07-2008, 12:02 AM

Thanks for the reply, however I already know exactly how I will gear up the GXH50. What I'm curious about is what people think about these different engines as far as reliability and performance are concerned. Plus I had a few specific questions about the Titan in the main post. I intend to utilize a 10 tooth sprocket on the drive shaft which will then lead to a 24 tooth sprocket on a jackshaft. On the other side of the jackshaft I will have my centrifugal clutch.
With these numbers I have a ratio of 2.4 to 1 giving me a rotational speed of 1,125 RPMs on the output side of my jackshaft. So far the only clutch I have found that engages near this speed is the hilliard extreme duty with the 1200 RPM engagement springs. It's a bit more than I wanted to spend but it's probably going to be my only option unless I do some design changes.
These numbers may change a bit depending on what the available engagement RPMs for the clutches in my price range are. And if I find contrary information concerning the idling speeds of the GXH50 which I currently know to be 2,700 RPMs. Or if I decide to go with one of these other motors I will need to change my ratios to match its idling speed and the engagement of my clutch.

Thanks again for your post..hopefully I'll be able to come to a decision soon.

conradcliff · #5 11-07-2008, 12:50 AM

After some more thought, I think I might want a clutch that engages closer to 2K RPMs as this would allow an engine RPM range right at 4400 which is right inside the beginning of the operational/power band of the GXH50.

Wow, I'm glad you made me think about that a little more

Edit: I'll probably be going with an 1800 RPM engagement clutch and a 10 tooth to 24 tooth which will give me a ratio of 2.4 and an engine RPM of 4320..right at the start of the sweet spot

Bikeguy Joe · #6 11-07-2008, 04:41 AM

Are you sure you want that kind of rpm before the clutch engages?
I don't know the redline on that engine, but I would think you need it to engage just a little over idle wouldn't you?

Large Filipino · #7 11-07-2008, 07:45 AM

I'm sure the Honda is a great engine but the Titan is a "complete package" if you will because it already has the 5 to 1 reduction gearbox so chaining it up is a snap. And as a testament to it's reliability my Titan engine has passed 4,000 miles and still runs like a champ shared between my bike and my trike.

conradcliff · #8 11-07-2008, 11:14 AM

Quote:

Originally Posted by Bikeguy Joe

Are you sure you want that kind of rpm before the clutch engages?
I don't know the redline on that engine, but I would think you need it to engage just a little over idle wouldn't you?

I could be wrong, at first I thought about having a clutch engagement engine RPM just above idle which is 2700 RPMs but at this speed the engine has very little power and is still not within its recommended operating range according to this chart:

I figured that if my clutch was engaging just above idle that I would be bogging down my engine at take off (though at my lowest gear I will have a considerable amount of torque so it probably wouldn't matter too much). As you can see from the chart the limits on the recommended operating range for this engine are right around 7700 RPMs.

Feel free to pipe in and tell me I'm wrong; I want to make sure I get this right the first time around.

Quote:

I'm sure the Honda is a great engine but the Titan is a "complete package" if you will because it already has the 5 to 1 reduction gearbox so chaining it up is a snap. And as a testament to it's reliability my Titan engine has passed 4,000 miles and still runs like a champ shared between my bike and my trike.

I was under the impression that the Titan motor did not come with the reduction box unless you bought the kit. If I could get the Titan for the advertised price of $179 w/$20 shipping and it came with the reduction box then I would definitely consider it. However, I believe you are talking about purchasing the entire kit which would not be copacetic with my current build plans. If I do decide to ditch all my plans I may very well choose the Titan kit as my primary option, but I don't think that will be happening.

If you want a better idea about what I'm planning for my build you can check out this thread.

Thanks again for the help guys...so far the GXH50 is keeping its lead...

HoughMade · #9 11-07-2008, 01:54 PM

The GXH50 idles at 2500 +-200 rpm, so you don't want it engaging below that and probably want to let it get a little more speed because it will bog if the clutch engages too soon, so you are right. I would want it engaging over 3000 and not all in until at least 4000, maybe more.

conradcliff · #10 11-07-2008, 03:23 PM

Excellent, I wasn't even think about partial engagement. I guess a clutch that is rated to engage at 1800 RPMs is just starting to engage at that point.
At 2.2 to 1 1800 give me an engine RPM of right around 4000 RPMs. I think that's probably where I want to shoot for.

Thanks again for your help!