CY 42/46cc Fitting

[DemonRC1]

Here's food for thought:


1) Our current engine crankshaft centers sit exactly 64.5mm off the chassis. 10mm of that is from the engine spacers underneath the fancover.


2) The 42/46cc crankshaft center is exactly 64mm from the bottom of the engine.


So there's a .5mm difference that can be madeup using a shim. So height wise we are good to go. Now for the gear plate mounts:


1) Current engines use a 58mm square pattern.


2) The 42/46cc uses a 96mm square pattern.


So all we gotta do is push the bolt holes out 19mm. This is perfectly doable and the engine crankshaft will sit in the same spot. The larger engine will sit exacty 21mm higher though (chassis to top of spark plug). Most of you guys that have built rollcages already have that clearance. Also, you have to change the location of the 2 bolt holes under the fancover. Last of all a larger clutchbell would be needed. I'm sure these can be bough off the shelf though. That's it. I already drew the gear plate up in Solidworks. I might get it machined sometime in the near future. This would be a nice alternative to the duel engine setup that LargeScaleRc has for their MCD.

 

[chevy1]

Now thats really interesting cat, thats definitly do-able, that be sweet an adaptor kit to fit the 42/46 motor plate for the gear side shims for the bottom and maybe a clutch adaptor the mt/tt has the room that now that motor would make alot of guys envious

 

[DemonRC1]

Just got off the phone with my partner. It's a go. Somehow we're gonna get a few plates machined in between the belt drive job and monkey around with a 46 we're gonna order. Oh, here's some specs on the engine. Sorry for the metric units as I'm too tired to do the conversions:


Stock GP290:


Bore/Stroke: 36mm/28mm


HP: 2.9


Torque: .19 Kg/m


Weight: 2.56 Kg


Stock GP460:


Bore/Stroke: 42mm/33mm


HP: 4.3


Torque: .32 Kg/m


Weight: 3.76 Kg


Both engines show they are rated at 18000 RPM with no load. Both show substantial dropoffs at 15,000 RPM. Normally I would assume the 28.5 would rev higher under load because of the lighter piston, crank, shorter stroke, etc. Here's the dyno's:

It shouldn't be hard to get this into the 5 HP range with some basic porting. I can see it pushing 7 HP easy with some professional porting and a good Go-Ped pipe like the Go-Ped Dominator for the 46 or the Jetpro for the 46 quad. 7 HP with a poop load of torque.

 

[Alex1]

Hi guys ,i think the rear dogbone under the R460 will be a prolbem ,cause the R460 crankcase is 1-1,5 cm taller down. And the tank ...

 

[lightning73]

Im thinking that amount of torque would wreak havoc on the drivetrain would it not?


Would probably lead to a lot of broken dogbone pins and c.v.d joints.

 

[DemonRC1]

Hi guys ,i think the rear dogbone under the R460 will be a prolbem ,cause the R460 crankcase is 1-1,5 cm taller down. And the tank ...

I did some measuring off the CY spec sheets and the 420/460 crankcase bottom is actually 3mm higher than the current style engine. 460 case is 28.6mm from chassis to bottom of the case and the current style is approx 25.5mm.


You right though about the fuel tank clearance. The fancover protrudes another 25mm to the rear and will hit the fuel tank. Good thing is that plastic tanks are cheap... except for the mould fee.

 

[Underdog]

Good bit of R&D here. If you can get this worked out to fit I will volunteer porting service on it. I'd like to see the inside of one of these.

 

[Alex1]

@DeamomRC so i think the current style engine has a spacer about 1 cm so there are not 25,6 cm ...there are 35,6 cm and the engin sit verry close to the dogbone ,i think it will not fitt.

 

[DemonRC1]

@DeamomRC so i think the current style engine has a spacer about 1 cm so there are not 25,6 cm ...there are 35,6 cm and the engin sit verry close to the dogbone ,i think it will not fitt.

MCD engines are already dropped to the plate and you have to dremel part of the fancover for clearance. If the MCD can sit an engine on the chassis and clear the dogbone then I'm sure we could fit a engine that has an extra 3mm of clearance on the chassis too. We would just have to line the engine up so that the dogbone passes through the fanshroud fins just like the MCD.


If worse comes to worse we raise the engine, tilt it backward, move it around, make it do a little dance, followed by a double backflip with a 1/2 twist and then connect it to the layshaft with a big mean fatass timing belt.


The point is that we don't have to settle on the same engine location as what is given to us because if gear mesh distances. I never planned on running this off of gears. I'll put that engine on the front bumper if I felt like it.

Good bit of R&D here. If you can get this worked out to fit I will volunteer porting service on it. I'd like to see the inside of one of these.

Thanks for the offer. I'd defintely give that a go cause I got guys here running your 29's and they haul balls. Oh here's the only images I can find of the port shape





If we can just pull the stock 15,000 RPM but with more than double the torque of a 30.5 after porting, we might have the makings of a fast engine with the right drive ratios. I dunno. I might be totally bonkers for thinking about it. It's just gonna be a really fun project to work on.

 

[chevy1]

The biggest issue to work out is the clutch and getting a solid setup

 

[Underdog]

I'm sure something can be done to squeeze a little more out of that set up. 33mm stroke is alot o play with. These engines are fairly inexpensive also.

 

[DemonRC1]

The biggest issue to work out is the clutch and getting a solid setup

I just need to get solid measurements off the current clutchbell and how far it is off the clutch housing. Then, we would need to make a new gearplate to match the bolt pattern, cut some spacers, and make a new clutchbell with a 10mm shaft. That part won't be bad. I'm just hating the fact that these engines have a huge fancover. It might be better to go with an airplane engine and go totally air cooled like the OBR twin.

I'm sure something can be done to squeeze a little more out of that set up. 33mm stroke is alot o play with. These engines are fairly inexpensive also.

Worse comes ot worse I'm gonna make a mean ass tiller with it.

 

[Obeast44]

I checked out those Evo motors like we talked about. They look pretty sweet!

 

[Alex1]

I ve mean if you put the new engine to the car it will be verry close to the dogbones,but i ve gess ,deamon, you ve made the geaplate for the beltdrive ,so ok i think you ll made it . One of my buddys put this engine on his Rovan (5B clone) without any cnc or same ,he says he put the cy cluthhousing in to the clutchhousing of the engine. I hope i ll become some pics from my buddy. @DeamonRC can you post some pics of this new cy baby??????. I messed the clearens of the backbone to the chasis-plate ,and man there are 33-36mm ,cant mess correctly....

 

[Alex1]

Hi DemonRC any news about the 42cc and how about the 2 speed trany for the redcats.???? Maybe a new gearplate with 2 speed and option for the 42cc engine ???? Will be a best car in the 1/5 world.

 

[Alex1]

Hi guys my 46cc on the way. I think on weekend will it go on in my mt. Pics folow.The engine is a beast ,the pipe is on the way ..... I think DemonRC it will be a good test for the beltdrive.









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[chevy1]

Alex any updates on the motor?? I see it mounted up in the mt but could you explain how you did it?

 

[DemonRC1]

I think I need to backup to a TT or MT for fitting. The XB has this dam fuel tank bracket that's in the way.

 

[Alex1]

Hi guys here some news , i ve made a adapterplate to connect the cluthhousing from the 46cc to the orig gearplate and my pipe is ready to lunch ,but the f.... air cleaner .....









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[grfilipp]

so any updates? has anyone started their motors?