GP460 Engine On Friction Drive

[5-7HEAVEN]

Thanks everyone for props, helpful hints and guidance. It wouldn't be interesting without you guys.

First dumb mistake on the project. I measured wrong on the drum spacer and had the machinist cut too much off the lip.

Oh well, I needed a paperweight.

Sir Jakesus, as you probably know, not much can go wrong on friction drive. Worst case specific scenario is if an object gets sucked up between the quick-release skewer or friction roller and the tire.

Bad case specific scenario is premature tire wear and roller slipping on wet tires.

Other than that, it's easy maintenance.

I ordered a new engine from davesmotors.com. It should arrive in a few days, but I'll be off-island until 5-12-09.

Back to the grinding and fitting of the pipe.

 

[5-7HEAVEN]

Now you see if we all went down to the pub together and got ****ed !!! you 2 would be off taking bike quantum physics, i on the other hand would get bored and be off socializing with the ladies !!!!(but your not allowed to tell the misses the morning after)

5-7 heaven, loving it, get that baby rolling and you will be ready for the drags in no time.....

Whatever happens in Vegas...

Nope, not quantum physics, more like "McGuyver" stuff.

Like last week, the rear tank's mounting bracket tab broke. So I tiewrapped it securely and ordered a new tank. A few days later the gas cap on the front engine falls off in traffic so I stuff napkins and an old vienna sausage can and tiewrapped that on.

So when the new tank arrives, I replace the broken tank and use the spare cap for the front engine tank.

Stuff like that, and engines and gearboxes and sprockets, etc.

 

[DetonatorTuning]

Well, the shop charged me $78.53 to machine .3125" off the clutch drum spacer's lip.

Well, at least he didn't charge me to machine the roller for slip-fit. He also taught me how to modify the roller for slip-fit. That'll save me time and $$.

I swear I'm gonna hacksaw the next spacer and save me the $78.

Steve, some scuttlebutt at gopednation claims that the 460 is good for 15,000rpm...stock, and 17,000rpm with headkit and ported.

Of course there was no substantiated proof of actual performance.

I think this engine definitely needs a tachometer.

Getting somewhat impatient searching for that 13:1 dome...so I ordered another 460 engine, stinger, clutch and exhaust tubing.

I'll use the pullstart from Zomby's engine but not the 3000rpm clutch springs.

Tonight I'll install the machined clutch spacer and grind down the engine channel to clear the pipe.

5-7,

i have a copy of the GP460 spec's from a german scooter site.

it shows the max free spin rpm for the stock 460 as 18,000. with the right gearing 15,000 is not unusual.

if you can get it to turn 17,000rpm with a goped and rider on it ,by any means, i'd say it's going be geared low enough that the speeds not going to be very impressive.

tach is a good thing, get the one "augidog" recommends, i have it and it's totally adequit and cheap too.

steve

 

[DetonatorTuning]

5-7,

can you use some small washers to get back to the proper spacing on the ring without doing up another ?

the clutch/ crankhousing right there doesn't have to be totally sealed, you could even install a small light shield to keep stuff from getting in there.

steve

 

[duivendyk]

The real question is: At what rpm does it develop max power?.Of course rev capability implies that with proper I/E tuning more output might be obtainable.Rollers would start to get pretty small at 15k plus though.

 

[DetonatorTuning]

DUI,

the spec's say in the stock configuration the peak HP is attained at 11,000rpm.

there is casual "evidence" that both porting and a good pipe can move this point higher in the rpm range.

personally, i have come to believe there is no real value in trying to gear to attain max attainable ground speed with this engine. it seems to work best all round to gear it to the speed of your preferred actual "cruise" at 11,000rpm. this will give all the accel. you could want, hill flattening cruising and reasonable mpg.

steve

 

[5-7HEAVEN]

Steve, I'll keep the drum spacer until I figure out how to reuse it.

So you're saying that maybe 1.375" roller might be the optimum spindle? At 11,000rpm speeds of 39mph is calculated.

Hopefully a Dominator pipe and rejetting should raise the hp power band. The headkit and higher compression should also hike the band.

dui, I have a Staton 1" roller if needed. At 15,000rpm, estimated speed of 38.8 mph.

 

[DetonatorTuning]

5-7,

yep 1.375", this engine is bull strong at 11,000 and will rev past that with ease right to the limit of ratio and operational losses.

you'll be real happy cruising 40-ish at 11,000. myself, i don't see any reason to spin it faster on a regular, constant basis. are you sure you want to delay the production of peak power till higher rpms ?

it may take the 1.25" to optimise your take off, spindle traction, terrain and weight. it's a toss up till you try them.

the Dom. doesn't really require more fuel, becuase it pushes the escaping charge back into the cyl. before it closes you actually run slightly leaner on the settings than with the stock box or Xbox.

steve

 

[350zdrftr]

can someone please pm me a link on how to put the GP460 onto a bicycle? is there a kit out there for it? thanks Someone local has a goped for sale with this motor pretty cheap and i am thinking about picking it up and swapping it to my bike

 

[kerf]

The 460 will pretty much mount to any bike motor kit such as GEBE, Staton or any kit designed for a small two or four stroke with a 76mm clutch. Having said that, it's not a friendly engine for the novice. If you choose a friction drive design, I suggest that you wait for 5-7HEAVEN to finish his and see what results he gets.