Daves gp460rs engine?

Some have used this engine. I think one with the 5 to 1 reduction gear box and one with a CVT I believe they are short lived but can be rebuilt rather easily. I once used a cag engine on a BMP friction drive. It was about a 2HP engine and quite fast. The gp460 should be a speed demon but may eat up tires fast. Let us know how it works.

I have installed my GP460 engine with friction drive onto two bicycles. This engine eats rear tires quickly. One tire lasted less than two weeks. Every time the engine roars to life, it will literally take a chunk of rubber outa the tire. One of my tires had divots 1" apart around the entire tread! I guess you'd have less wear if you raised the roller off the tire on every start, your tread would last longer.
Another problem is that this engine has a VERY narrow power band. While riding up steep hills, your engine rpm will drop down to a crawl, even with a 1.25" friction roller. This engine works VERY well with NuVinci hub or shift kit. However, with the shift kit, the engine devours 8-speed bicycle chains and low rpm clutch springs. I run a 460 engine frame-mounted with shift kit. It is very fast but very undependable. My friend runs a 460 with Staton gearbox and NuVinci hub. His thicker chain is very strong, but his engine also eats clutch springs.
Good luck. This engine is very powerful and will propel your bike past 40mph QUICKLY. However, be prepared to maintain it on a daily basis.

I have a 26" Diamondback with original disc brakes. If you ride in bumper-to-bumper traffic like I do, you might need to upgrade to 203mm discs.

My next project is a Diamondback 29er and a Kona 29er. I'll be using another GP460 engine and a Tanaka 47R engine for comparison. I will try to run NuVinci hubs on each 29er bike. That way, I can use stronger bicycle chains.

This is my 460 bike:

http://motoredbikes.com/attachment.php?attachmentid=30075&d=1294959863

Tight little installation, im wondering what the drive side looks like.
Chain line might be off a bit, since you mentioned 8 speed chain im assuming your talking about the bikes derailleur systems chain.
When you install the shift kit freewheel crank, you some times need to shim out derailleur chain ring to get the proper chain line.
The inner chain ring might be to far out or to close
(in or out in relation to the frames center line)
Were talking 5 or 10 extra shim washers depending on the washers thickness.
Prop or hang the bike up so you can peddle it through its gears and watch the chain line... I'd bet that's your culprit.
Good luck.
BBB

Thanks for your input, buzbikebklyn1. There was a lot more room when the carb stuck straight up. However, the gas tank and the expansion pipe wouldn't have fit.
There's lots of room on the chain side. There's a 63-tooth drive sprocket and a 30-tooth chain ring, which has been shimmed into position.

that looks like a very speedy bike 5-7heaven, i like the way you mounted the engine. gives me ideas for the new dax motor i bought

Thanks, Shiloh0. It is my quickest bike.
bigalan, with 25:1 oil/fuel ratio, this sucker spits out a lot of oil. I might have mispoken; ya need to wipe the oil mess after every run. Then again, my Tanaka has 50:1 f/o ratio and still spits quite a bit of oil too.
Be sure the engine is well-insulated, or your hands might get numb. I insulate my engine drive system with swatches of bicycle tire, not bicycle tube. They work well.

The clutch spring broke recently and the 5:1 tranny needed relubing. After filling the tranny with grease, the 460 was replaced with a 2.8hp Tanaka 47R engine. I mounted the Tanaka upside-down too, so that I was able to re-use the Happy Time expansion pipe and HT 4-liter fuel tank. Engine size is similar, although the 460's exhaust tube hugs the bike frame tighter.
The 460 with SBP expansion pipe is MUCH quieter than a Tanaka 47R with the same pipe. With the Tanaka being so loud and all, it's hard to wind it up to its max. It's no slouch, though.
For the price and availability, ya just can't beat the GP460 engine. It's the most powerful engine that will bolt onto available 78mm engine drives. The Tanaka 47R MIGHT be a good competitor to the 460 engine. However, it is EXTREMELY rare and expensive, since it's no longer in production. I was lucky to buy a used 47R minus muffler and air cleaner for $115 AND a new complete 47R for $350. A 47R in new condition can run you up to $1K, depending on who you buy it from and if they sell it to you ala carte. The shift kit and the NuVinci hub work extremely well with the 460. Single-speed systems won't work well with hills.
For the amount of power it produces, the 460 has excellent gas mileage, much better than the Tanaka.

Are you running the clutch saver springs? The stock clutch springs are way to stiff and brittle and engage way to high up in rpm's, thus your narrow powerband. Do yourself a favor and get the clutch savers, you'll never go back!

5-7HEAVEN said:

Thanks, Shiloh0. It is my quickest bike.
bigalan, with 25:1 oil/fuel ratio, this sucker spits out a lot of oil. I might have mispoken; ya need to wipe the oil mess after every run. Then again, my Tanaka has 50:1 f/o ratio and still spits quite a bit of oil too.
Be sure the engine is well-insulated, or your hands might get numb. I insulate my engine drive system with swatches of bicycle tire, not bicycle tube. They work well.

The clutch spring broke recently and the 5:1 tranny needed relubing. After filling the tranny with grease, the 460 was replaced with a 2.8hp Tanaka 47R engine. I mounted the Tanaka upside-down too, so that I was able to re-use the Happy Time expansion pipe and HT 4-liter fuel tank. Engine size is similar, although the 460's exhaust tube hugs the bike frame tighter.
The 460 with SBP expansion pipe is MUCH quieter than a Tanaka 47R with the same pipe. With the Tanaka being so loud and all, it's hard to wind it up to its max. It's no slouch, though.
For the price, ya just can't beat the GP460 engine. It's the most powerful engine that will bolt onto available engine drives. The shift kit and the NuVinci hub work extremely well with the 460. Single-speed systems won't work well with hills.
For the amount of power it produces, the 460 has excellent gas mileage, much better than the Tanaka.

Click to expand...

I have always replaced the 8,000 rpm original clutch springs with either Staton or DDM springs. Staton has a wider variety, ranging from 2500rpm to 4000 rpm springs. Do NOT use the 4000 springs. Your motorized bike will sound and respond exactly like a modified moped. There will be no low rpm range at all, only mid and high rpm.(Ask me how I know that, lol.)

You can also use pocket bike clutches on 460 engines. These clutches are on engines having a tapered crankshaft. GP460 engines also have a tapered crank with the same dimensions. They also have a slot for a keyway, but no key. (You can use the 460 flywheel key for the pocket bike clutch on a 460 crank. The pocket bike clutch has three clutch springs which are longer and of thinner wire. The 460 clutch shoes expand outward, perpendicularly from the crank's centerline. Pocket bike clutches expand from pivot points on its three shoes, similar to automobile and bicycle drum brakes.

Pocket bike clutches are silky smooth and engage right off idle. Some 460 clutches can grab more abruptly, although not as harsh as a Tanaka 47R single-spring clutch. 460 clutch shoes seem to have more contact with the clutch drum, maybe due to its engagement design. Pocketbike clutches tend to engage the drum on their trailing edges.

When using pocket bike clutches on 460 engines, the 12mm nut securing the clutch needs to be ground down a few millimeters.

Stock 460 clutches at DDM cost $54:

http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.2475/.f

Pocket bike clutches are on sale at DDM for $7.00:

http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.3821/.f

FWIW, my friend and I have also broken pocket bike clutch springs on 460 engines. It could be because of our no-pedal assist from standing starts.

5-7HEAVEN said:

I have installed my GP460 engine with friction drive onto two bicycles. This engine eats rear tires quickly. One tire lasted less than two weeks. Every time the engine roars to life, it will literally take a chunk of rubber outa the tire. One of my tires had divots 1" apart around the entire tread! I guess you'd have less wear if you raised the roller off the tire on every start, your tread would last longer.
Another problem is that this engine has a VERY narrow power band. While riding up steep hills, your engine rpm will drop down to a crawl, even with a 1.25" friction roller. This engine works VERY well with NuVinci hub or shift kit. However, with the shift kit, the engine devours 8-speed bicycle chains and low rpm clutch springs. I run a 460 engine frame-mounted with shift kit. It is very fast but very undependable. My friend runs a 460 with Staton gearbox and NuVinci hub. His thicker chain is very strong, but his engine also eats clutch springs.
Good luck. This engine is very powerful and will propel your bike past 40mph QUICKLY. However, be prepared to maintain it on a daily basis.

I have a 26" Diamondback with original disc brakes. If you ride in bumper-to-bumper traffic like I do, you might need to upgrade to 203mm discs.

My next project is a Diamondback 29er and a Kona 29er. I'll be using another GP460 engine and a Tanaka 47R engine for comparison. I will try to run NuVinci hubs on each 29er bike. That way, I can use stronger bicycle chains.

This is my 460 bike:

http://motoredbikes.com/attachment.php?attachmentid=30075&d=1294959863

Click to expand...

I had been wondering if anyone had done this. looks nice. very nice. and perhaps quick...

Thanks.

The 460 is an EXCELLENT engine for a motorized bike. My pal Rick has his up to 53mph on flat ground.

Once I find a reliable clutch, I'll run my 4.5hp 460 engines. Until then, my 2.8hp Tanaka 47R engine is a good substitute.

5-7HEAVEN said:

Thanks.

The 460 is an EXCELLENT engine for a motorized bike. My pal Rick has his up to 53mph on flat ground.

Once I find a reliable clutch, I'll run my 4.5hp 460 engines. Until then, my 2.8hp Tanaka 47R engine is a good substitute.

Click to expand...

do you think you could mount one center frame like a CG? and direct to rear sprocket?

Sure, the 460 will fit center-framed. You could adapt a universal mount or fab one up yourself.

You will NOT be able to run directly to the left rear sprocket without a jackshaft and extra sprockets. The smallest engine sprocket is 8mm 6-tooth. The largest available 8mm rear wheel sprocket is 72t, yielding 12:1. You need at least 18:1 to use the 460.

A good alternative is to bolt the 5:1 pocket bike gearbox onto the 460. Then you'll need a jackshaft and 3.6:1 more gearing, at the least. If you ran a shift kit, a jackshaft would be needed to bring the chain line inward. If you installed a left rear sprocket, the jackshaft would be needed to transmit the power to the left side.

5-7HEAVEN said:

Sure, the 460 will fit center-framed. You could adapt a universal mount or fab one up yourself.

You will NOT be able to run directly to the left rear sprocket without a jackshaft and extra sprockets. The smallest engine sprocket is 8mm 6-tooth. The largest available 8mm rear wheel sprocket is 72t, yielding 12:1. You need at least 18:1 to use the 460.

A good alternative is to bolt the 5:1 pocket bike gearbox onto the 460. Then you'll need a jackshaft and 3.6:1 more gearing, at the least. If you ran a shift kit, a jackshaft would be needed to bring the chain line inward. If you installed a left rear sprocket, the jackshaft would be needed to transmit the power to the left side.

Click to expand...

ok cool thanks. so there's no putting a full size (415 chain) sprocket on the engine/clutch and running it back to a 56tooth left side sprocket like the HT kits? is that what you meant with the 72 tooth? and still out of the envelope?...

If you ran a 10-tooth engine sprocket and a 56t 415 sprocket, you'd get 5.6:1.

The bike would not move from a standing start, and no power at all speeds.

5-7HEAVEN said:

If you ran a 10-tooth engine sprocket and a 56t 415 sprocket, you'd get 5.6:1.

The bike would not move from a standing start, and no power at all speeds.

Click to expand...

got it. thanks. all this GP stuff is new to me. i appreciate the help

No problem.