Rc-1/c-1 case differences?

[zekefab]

Recently received another rc-one to build this winter and I have questions on the case from the guys that know . It’s the 94cc kit and everything correct came with it however I noticed the case has duel cylinder mount provisions. Anyone seen this ?
 
I did measure the crank opening and noticed it’s been opened up to 78mm.   My thought is maybe rc cases were out so they modified a c-1 to suite? doesn’t bother me so long as everything else is the same. Hence why I’m asking for knowledge. 

[90GTVert]

I just got a new RC1 case and hadn’t paid any attention to it as it’s just the beginning of a parts pile to wind up a 100cc. Figured I better take a look when I saw your post…






Same deal as yours. It looks like Malossi is taking the easy way out and trying to get rid of C1 cases by boring them to fit the larger crank.

Here are pics of part numbers. Haven’t checked if they’re the same as RC1… may be since they’re prob cast the same and then machined for each.






The box def is the RC1 number. C1 is supposed to be 5716654.





This is gonna be an issue for me because mine will be an FL100 with some pretty massive ports. Here’s a base gasket showing that the port will run into the stud holes that shouldn’t be there. That leaves me with a void to deal with once cut. Not something that can’t be dealt with, but I shouldn’t have to.




I’m gonna get in touch with ScooterTuning and see what they say. I’m sure this is from Malossi and has nothing to do with retailers, so I’m not really sure that they can do much other than offer a return… which leaves me looking for real RC1 cases (good luck I’m guessing) or switching engine platforms. Polini PRE and 2FAST Passion cases cost double the RC1. I’d prob have to fill the boost port area anyway so the studs aren’t awful… but it would be nice to get what you order from big companies like Malossi that boast about their top notch manufacturing.

[90GTVert]

Part numbers are different on the proper RC1 that I’ve had a few years now.

[zekefab]

Interesting. Mine came through scooterpartsco but everything came from Malossi . Thanks for the reply Il be fine with this case but like you mentioned for going bigger that’s not ideal.

[aeroxbud]

I can see why Malossi have done this. It makes for easier production runs. But with the newer big cylinder in the pipeline when they implemented this new design cases. They must have known it would cause problems.
Unless there is another case for the bigger cylinder? But surely they should have announced that when they released the cylinder? 🤔

[Lucass2T]

Whats the problem with putting some threaded aluminum plugs in the holes?

[90GTVert]

Nov 15, 2024 4:27:32 GMT -5 aeroxbud said:

I can see why Malossi have done this. It makes for easier production runs. But with the newer big cylinder in the pipeline when they implemented this new design cases. They must have known it would cause problems.
Unless there is another case for the bigger cylinder? But surely they should have announced that when they released the cylinder? 🤔

My thought is that they have the C1s around. I assume they don't sell like the RC1s, because basically everyone that's not in a specific class gets the bigger RC1. Bore it for the larger crank and get it out of the warehouse. I was wondering if they are saving the RC1 cases for the 100cc because I'm sure they're aware that big ports on most 100s are gonna be an issue with the extra holes.

[90GTVert]

Nov 15, 2024 6:30:16 GMT -5 Lucass2T said:

Whats the problem with putting some threaded aluminum plugs in the holes?

I can work with them, and assume I will have to because I know ScooterTuning can't do much about it since Malossi is shipping them out this way when they order an RC1. I asked if there was any way to get a real one, but again I kinda already know the answer so I told them if nothing else I wanted them to be aware because I probably won't be the only person to be a bit upset when they receive a modified C1 case.

I pretty much figured I would make an aluminum stud and install it with JB Weld, then port as usual, grinding away part of that stud. It's mostly just disappointing because I ordered a case with a solid base and Malossi saved themselves some money and did this. These are supposed to be high end racing parts, not whatever is lying around the warehouse that's close enough. It's disappointing because these things are a ton of money to me and I'd like everything to be right.

Honestly the difficult part for me is something that I'd have to deal with using either version, which is filling the boost port area to match the narrow port that's on the S6 100 and most of the 100s. It would be really nice to get someone to lay some beads in there with a TIG... but then you risk warping. I believe hypervertical did a bunch of welding to a Minarelli case to backfill it for porting instead of JB Weld filling like I do and said he wound up having to align hone the cases IIRC because there was some warping. I'm sure it can be done, but I'd imagine a welder would have to be very careful and do a little at a time... but I don't know anything about aluminum TIG. Not sure if it's something I could do with MIG. Never even tried to use mine with actual MIG yet and only use flux core in it so it would be a heck of a first project.

The downside with welding would be the base gasket area. If filled with epoxy, I've seen John mention using glass up against the surface to keep it all flat, but you couldn't really do that with welding unless maybe some sort of thick plate could be made and bolted down over the area perhaps. Something like copper I guess... not really sure what's cheaper that would hold up and also not get welded on in the process. Even then, I guess that's not really a guarantee that it is truly flat like glass should be.

[Lucass2T]

Yeah it's not a good move of Malossi. I would be upset too. Not much you can do about it apart from making involved people and the folks here aware.

[90GTVert]

ScooterTuning checked another RC-1 that they have and it's a C-1 too. They're sending my pics to Malossi to see what they say.

With the other filling that I'll have to do, it's not a huge deal... but if we can keep a company honest, that would be nice.

[90GTVert]

Malossi gave ScooterTuning an answer. Malossi claims that this is the new design of the RC-1. The rep at ScooterTuning is with us, thinking it's Malossi's way of getting rid of some old stock. They checked a Piaggio RC-1 on hand and it doesn't have the C-1 stud holes like the "new" Minarelli version does.

It's awesome spending a bunch of money for parts from a manufacturer (Malossi... not ScooterTuning) that think's you can't smell their BS.