Cuyuna 440cc in Yamaha G9

[saamember4880]

The more I think about the supply demand of the intake and the cooling fan combined, the more I'm thinking about separating the 2. I could run the intake to the front of the cart and the cooling fan to the front wall under the seat - or maybe the side with a louvered vent, that'll point forward for maximum airflow to the cooling fan...

[sho305]

I had huge dust problems, my cart sees little pavement. Everything under there gets coated thats why I ran the intake to front. I did think about air scoop in the center where less dust is, but its all open and with the lift it doesnt seem to make the body hot. I also put the muffler under the rear bumper that probably removes some heat it had. I would have to use plastic or rubber for an airdam under there as I've run over logs and stuff that would hit lol. Another idea I had was just blow air out under the rear to get rid of hot air, or vent the bagwell and blow it out there. You have to be careful soon as you vent the body you hear noise from engine.

[saamember4880]

While it's less ventilation than I initially planned on, I do have quite a bit of ventilation in front of the bagwell still. As you may have seen in some of my first posts, I cut out both the top surface and the front vertical surface of the bagwell and covered it with expanded metal. Due to modifying the cart's frame, I had to relocate the gas tank to the bagwell (hand-bent the panel covering it in the pic. It isn't perfect but it'll do and it looks a whole lot better than looking at the gas tank!) so I'm left with just the top surface being vented. I think it's still a pretty significant amount of venting. I still agree with you as far as clean air goes. I've since decided to keep the intake and cooling air sources separate, running the intake to the very front of the cart, probably through PVC pipe. I'm toying with the idea of designing a 3D printed "scoop" to sit somewhere in the front, maybe even through the hood(?). The cooling fan will run through a vent I'll be putting in the wall under the seat on the passenger side, probably facing forward. The vent will connect to a 6" flexible hose that will run to the cooling fan. I realize that putting it through the sidewall under the seat with louvers directing air into it would likely grab more air and therefore provide better cooling, but I can't stop thinking aobut how easy it'd be for the louvers to get hit and eventually break, leaving me with a big gaping hole. If I'm forced to take this approach, I redesign the vent and cover the front hole with some sort of decorative design. Short of test fitting, I finished designing both the cooling fan's hose attachment and the intake vent - complete with a scorpion sourced from an image of the actual Scorpion emblem, converted to a 3D item, then embedded into the intake's grill - because I can lol! In the picture, the vent is colored to match my intended material colors, unless I change my mind... again.

[sho305]

That should work. I have a friend that has printed costume parts its pretty cool I should get into it. A lot of people just holesaw close to each other and put a grill over it, then its not a hole sort of in the body.

[saamember4880]

Yeah, I've been there with the hole saw. I'm trying to make this a little prettier lol.

I"ve always been curious about 3D printing and have even had a resin printer that I got from a coworker collecting dust for over a year before I really 'discovered' a use for it. I'm not really into printing toys, although I acknowledge that it's those people that do a lot in driving the 3D printing industry so I appreciate them! Once I started finding the need for custom functional pieces, I got hooked and bought an FDM printer! Resin is good for fine details but can be more brittle, FDM is a good economical choice for larger prints and has more color and material options for different physical characteristics (from flexibility to oil/heat resistance and many more) that can come into play when considering the environment your finished pieces will be subjected to.

It's relatively inexpensive to get into these days. I got into it back around May and am still geeked about it! I have an Anycubic Kobra Neo (decent beginner printer for price and results) and it only cost me $150 brand new! You can actually find the same printer even cheaper.

I'm still very new at designing so I use Tinkercad for all my CAD needs. It's UI seems a bit "cartoony" but is very easy to use. It's free and designed for classrooms so the website includes tutorials. It has a large library of shapes to start a design with and all you do is drag them onto the workplane and modify dimensions to suit your needs. Once your design is complete, simply export it to your computer! You can also save any of your own designs in the shapes library for quick re-use. All saved shapes are shared across it's platform though so don't save anything in the shapes library that you want to keep private!

If you go back through my comments in this string, you'll see the kinds of things I've designed, all on Tinkercad (99% of my designs are for this project). It's also browser-based so you can access your designs from any computer with an internet connection - which is very handy for me because I work away from home and my work computer has a 32" screen, so I prefer it over my laptop (not to mention my laptop is a POS that can barely run the slicer). It isn't as "in-depth" as other CAD programs but it's been able to do everything I've needed. As with anything, the more I use it, the better I get at it.

Additionally, you can import shapes you find online (came in handy so far for bolt threads, my flexible hose connection, and the Scorpion emblem).

If you are interested in 3D printing and want to do more than just download files to print, you should start messing around with CAD and slicers first. I use Cura for FDM and Lychee for resin - both are free. Slicers, while having been around a while now, are still in their infancy, so there's a TON of settings you need to familiarize yourself with. I'm mostly referring to FDM slicers. Resin is simpler. Most slicers DO have preset profiles (they'll get you close) for whatever type of material you want to use but regardless of being mass-produced, each individual printer has its own set of unique print results. Everything has a learning curve.

Tinkercad also has breadboard-based circuit design, which I've played with a little bit. You can make your own circuit and it'll simulate the results.

[sho305]

Wow thats great! Years back I did autocad and cnc so I figure its not that much different. I have a friend he prints helmets and body cladding among other things just not had time to mess with it. Things been busy lately. Thanks for posting the info, I plan to look into it soon.

[saamember4880]

Anybody that likes to help, please note that I have a couple questions at the end of this post and I'd greatly appreciate any feedback you can offer!

As predicted, things have slowed down since moving the cart back to my house. I'm only home about 45 hours/week. I DID manage to make something of a shroud for the gas tank. I'm no fabricator! I think it looks good enough to serve it's purpose though.

Additionally, I got the gas tank sending unit wired, the fuel line ran, and the pump's pulse line connected (I'm thinking about patching it into some 5/16" brake line with hose just at the connecting points though, since it has to run pretty close to the pulley). I haven't started the bulk of the wiring at hand yet. It can be tough balancing tinker-time and wife-time but if one of those have to suffer, I'm choosing the tinker-time to suffer the most! (I know what side of my bread is buttered lol)

Meanwhile, I've completed designing my custom cooling intake duct. I haven't started printing it yet, as it's going to take over 3 DAYS to print and will be my largest print to date (my printer is barely large enough to do the job in one piece)! I DID print some size samples to make sure my end fittings will work. The end that connects to the flexible tubing was easy. I just downloaded a .stl file and it fit perfectly with no modifications. The engine side took a couple trial fits before getting the size just right but it's good to go now. This piece will look exactly like my drawing design - but in black. I showed it in an earlier post but I attached it again for those that haven't seen the previous posts.

And finally, I tried pull starting the engine. I found my compression is still way too low (60 PSI). I'm pretty sure it's because since I didn't have a hone, I didn't bother honing the cylinders. I now have a hone ordered and it should get to my house before I do. I'm going to tear the engine back down and hone the cylinders. If this doesn't do the trick, I'll 'give up' and take the cylinders and pistons in to a local small engine shop and get them sized for oversized rings - I'm not experienced in this department and am tired of taking this engine apart!

Question time:

First, I keep ordering jackshafts and keep getting the wrong sizes! I've about given up! I'm wondering if anybody thinks my current setup is strong enough to hold up. The first shaft I ordered was the right outer diameter but is more of a tube than a shaft, with a (roughly) 5/8" hole running in the center. I realized that once I find the part I need, I tend to stop reading the descriptions quite as well as I should when comparing prices. I KNOW all the dimensions but for some reason, when I ordered the last one, everything was exactly as I intended but for some reason, I FORGOT I need a 25mm shaft and was instead thinking I needed 1"! Anyway, in order to continue mocking everything up, I ran a 5/8" all thread through it (yes, I misquoted the size twice previously. It's 5/8" though. I promise this time). It took cutting the all thread in a way that left the leading edge of the thread at a sharp angle and it actually cut some shallow threads all the way through the shaft, using an impact wrench to drive it - so I know it's very tight. I did this primarily because I was concerned with the hollow shaft collapsing under torque - as well as to give me something to hold the secondary clutch in place. And finally, I cut a 1/4" keyway in one end of it for the secondary pulley. While I didn't go all the way through the wall, it only left a thin wall (maybe I should weld the keystock into it to make up for the thin wall?). The question is does anybody think this will fail? I kind of feel like it should be plenty strong enough. Given it's unique nature, I won't be surprised if nobody weighs in on this but I'm so sick of not getting the part I need! I don't have a great picture of this. Hopefully my description coupled with the pictures I attached are good enough to get the idea across.

Second, is it possible to run the engine's stator parallel to the S/G's circuit? I have no reason to think I'll need more power than what the S/G can offer but it'd be a shame to let the stator go to waste. I'm sure I'd have to use the engine's original regulator/rectifier, which isn't a big deal. I'm more concerned with the two charging systems 'confusing' each other.

[saamember4880]

Originally Posted by sho305

Wow thats great! Years back I did autocad and cnc so I figure its not that much different. I have a friend he prints helmets and body cladding among other things just not had time to mess with it. Things been busy lately. Thanks for posting the info, I plan to look into it soon.

No problem! I want to contribute as much as I can in return for any/all the help I've been able to receive on this site!

It sounds like you're likely much more advanced in the CAD department than I am but if you ever have any questions you think I may be able to help you with, feel free to contact me!

[saamember4880]

The first part of the cooling air intake duct is complete. The 3D printer kept messing up on this 2-1/2 day print so I split it up into 4 pieces and glued them together. I would've preferred it to have been printed in one piece but I got tired of wasting filament on unpredictable issues - not to mention the lost time. I need to get more dimensions, including a couple radiuses in order to complete the vent, which after that, I'll just have to connect my flexible tube to tie both pieces together. Sidenote: in the picture I posted, you can see a milk crate under the frame. This is the first time I really noticed just how significant of a difference my lift kit and larger tires made! The cart is sitting on the floor at ride height and the crate just slid under there when I tapped it with my foot. It isn't even touching the frame there! Of course, clearance reduces the closer you get to the axle but still pretty cool.

I also pulled the engine...again and honed the cylinders. I ran out of time before I could even give it a couple test pulls to see if compression improved but the cylinders look much better and the resistance when turning the motor over by hand feels a lot stiffer. Maybe after all the Turkey day stuff is done, I'll be able to get back on it before heading out for another week.

On another note, I'm looking for a LSD conversion plate set. They make them for EZGOs and newer Yamahas. I just need to figure out if I can find one that fit's my G9. Does anybody know anything about this? Maybe even if the one for the G16's would work, even with some slight modifications? Link for reference: https://www.ebay.com/itm/18298883606...ntid=101684100

They're also too expensive (the ones I found specifically for golf carts. Others are available for as low as $25) for me to take a gamble on so I'm trying to figure out which dimensions and spring compression would work with mine. As usual, any help would be awesome!

[saamember4880]

LSD: Limited Slip Differential