SunL SLGK-160 Engine Upgrade Swap

[kittletstv]

I am looking for opinions out there about my possible / intended gy6 type B engine swap upgrading to a Polaris Scrambler 500 4x4 engine & trans set up? I really like the ride & handling of the buggie, but I would definitely like more power for the trails we ride on in the mountains & forest trails in northern AZ. I am not familiar with these quads but jumping from approx 9hp in the type B to 38-42hp with this quad set up depending on the pipe sounds real nice. The only draw back I found so far from a friend is that this set up only has Hi/N/R, I was hoping to go with a Lo/Hi/N/R if possible. Any opinions or suggestions as to my potential project?

[bear]

Is there any thought to how much modding will be involved? the time involved? and have you considered the various "bolt on" upgrades you can do to your existing powerplant, and CVT that might give you what you're looking for?

[kittletstv]

Yes, I know that there would be quite a bit of fabricating and probably other incidental items needed. I have thought about the normal cvt spring & roller / slider weight changes I've seen discussed here but I have always been told that there isn't much if any hop-up parts for the type B engine -(2 bolt valve cover), is that true? Seems strange to me why not since I've been told that it is actually a more durable version of the gy6 with approx 1 - 1 1/2 more hp and bigger valves than the standard gy6. I haven't decided for sure yet but there is no way to argue the hp difference between the 2 engines. I don't intend to fly up the hills and soar over the top but I would like to be able to explore the terrain without having to get out and push it up some of the hills or add a winch to do it due to the lack of power while my kids pass us up the hills on their Baja Carbide fat tired mini-bikes with the 6.5 hp engines.

If I do decide to stick with the current type B / gy6 powerplant what is the best way to get the most low end torque / low end to mid range power out of it? Any idea of a projected increase if I went with the various "bolt on" & CVT upgrades?

I always remember my Dad telling me as he was teaching me how to rebuilld my 1st small block chevy years ago for street racing (assembling it in the kitchen after we put the table outside & made room for the engine stand inside) that there is nothing like raw, pure horsepower, and that you could make a brick fly if you gave it enough power.

Ahh, to Dad's that make a difference in our lives & the good old days!

[JERSEYDEVIL]

my thoughts
either you might want to consider a different buggy for your build or a different engine to swap into your buggy.

1) i'm not so sure how a polaris engine/tranny combo would fair mounted to a swingarm, bouncing up and down.
2) the wait of this combo might be very taxing on your axle/ hubs
3) a swingarm setup is only comfortable up to a certain speed on most trails. i cant tell you how many times i had plenty of pedal left on my yerf and couldnt use it because of the rough terrain and i have a ton of time ,fab and $ in handling mods. including extending the swingarm 3" which helped alot
4) to get the maximum impact from a 500 swap i would definitely fins a 250 I.R.S. chassis

[kittletstv]

Thanks Jersey for your input. I really appreciate your ideas & opinions, especially seeing all of the posts that you have shared with your quality of work and fabrication ideas. Do you know if the bolt on hop up parts for the standard gy6's will work on my type B engine that came in the buggie? If not, in your opinion would I be better off swapping over to a standard version of the gy6? If so which brand would you recomend?
Thanks again for your help.

[wildbob]

I may be wrong here. But I was under the impression that you could really tweak out the "B" cases.. You might try spmotostore.com as I think they have hop-up parts up to 232cc kits for the "B type" GY6

[kittletstv]

Thanks for the info. I'll look into it today.

[JERSEYDEVIL]

as far as what works on both motors i'm not completely sure. i know the head and jug are different and the cam shaft selection i believe is more abundant for the 4 bolt. as far as clutching not 100% sure.
i prefer the 4 bolt for the parts availability. the standard gy6 w/out the internal reverse is what i use and prefer. as far as a brand of motor, i have always had luck w/ Howhits.
i would say Tom syc could give you a better rundown on the pro's and cons of 2 bolt vs. 4 bolt.
every custy motor that's been through my shop thus far has been 4 bolt just because they are more common.
as far as swapping out a whole motor via paying to having one built for you if you wouldnt do it yourself i would recommend either Tom Syc or my shop. I have had great experience w/ Tom before i opened my shop and he stands by his work. I have an in house engine tech, Jeff, who is awesome. used to manage/mechanic an NHRA drag bike team and he's one of my best friends. all i can say is there is no "good enough" in his vocabulary. it's either on the money or it doesnt go out the door. if he didnt have this attitude i wouldnt have him in my shop and i would just stick to selling parts and fab.
but w/ the buggy you have i would 1) pimp out a 150 or 2) swap a cn or cf250 in the swing arm and do some suspension mods. i started out doing stuff to my 150 and still have it, but it's good training for fabbing.
if you want to move up in motor and buggy i would keep the 150 and hunt down a project i.r.s. buggy to do a swap into.

[kittletstv]

Thanks again for the info. I'll keep it in mind and start my research.

[kittletstv]

Well, I have thought about it and decided to go with a major mod on our current SLGK-160 buggy. I finally got tired of screwing around with the current Type B GY6 hoping for enough power for the mountain / forrest trails we ride on here in AZ. So I have purchased the complete rear IRS, brake system, and engine / IRS mounting plate assemby off a Joyner 250, and a complete '99 Polaris Trail Boss 250 to start with. I was hoping to find a 400 - 500 with Lo/Hi/Rev but never found one at a resonable price locally. I got the '99 Trail Boss for $200.00 with good compression, good plastics, etc. and the original tool kit still in the bag. At this point it appears that it just needs the normal carb clean, etc. I am also intending on lengthening the frame in the cockpit area about 6" as well. I know that it's going to be a lot of fab work but oh well, life is short so I might as well do what I enjoy while I can.