Stage6 MK1 Peugeot Engine

So a while back I figured out the Stage6 Hobbit conversion and had great success running it. I wanted to expand it to other platforms so people can play with big power.

I want to make this thread to show the process that goes on behind the design of Treatland parts and the days and months it takes to get things exactly perfect before they are ever even seen by the public eye.

I hit up my buddy Lee, who introduced me to mopeds in highschool with a 103 and asked if he was interested in me building an engine for him. He said sure and sent me over a Malossi case with Doppler crank he had around. I ordered a Stage6 kit and got to work.

This is the first Peugeot engine ive ever built and it was a process. I wanted to share that process as well as how to do it. I will make the parts available for anyone that wants to do it after Lee and I have successfully tested and run it.

Here's the kit fresh opened. I honestly didnt even know if this whole project would work and said fuck it and bought parts and tried it, because you don't know if something's possible or not if you don't try it.


Okay so going into this, I knew both Peugeot and this kit had 40mm stroke, i didnt know anything about stud spacing or deck height. I figured if it didnt work, oh well, spare kit for my hobbit. So first I took the hobbit spacer file and did a quick and dirty adjustment of the studs to match the 103 rectangular pattern. I could then kinda get an idea of how the Oring was going to seal and if it would seal.


I found that it would but the transfers will bleed into the studs. Also since the studs are rectangular, I would have to take some material off the skirt to get the allen bolt heads to fit. I printed an initial spacer with the studs proper and sharpied up the cylinder for dremeling


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Okay onto initial dremeling and test fitting and checking for bolt head clearance. Im using M7x1 Allen bolts here that I will use to attach the adaptor to the case.


You can see its close to flush here but not perfect. needs more dremeling


Here's a look at the adaptor to jug gasket after initial dremeling. If you envision in your minds eye, the charge will be allowed to bleed between transfers, but will not escape out or into coolant passages, so we are good to go!


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Okay, once i got the spacer fit flush against the jug it was time to make it work with the case. So at this point the only things I was concerned about was proper stud spacing and roughing in transfers close to what they should be. Not worried about deck height until later.

Heres a second printed spacer with sort of correct transfers.


Heres it on a table


You can see that the case has to be bored. Time to split it!


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Alright, so here's the stage6 cylinder trying to go into an unbored case. not gonna happen.


Initial bore, yeah it gets close to the studs, oh well doesnt matter if it works and is strong.


Initial check with the spacer. seems good but the piston skirt is VERY close to that part on the right, I was not gonna take any risks so I took it apart and knocked that down with a dremel


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Here are a few pics of before and after I knocked the ledge down to make clearance for the piston skirt


Spacer and bore is looking good now!


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Okay next step is to figure out how thick i need to get the spacer to get my port timing proper. So I mock put the crank in so I could rotate it to BDC shown here:


Then I marked the cylinder bore with a sharpie here:


Removed the piston and measured the gap from the bottom of my sharpie mark to the bottom of the exhaust port. Then I knew how much thicker my spacer was than It needed to be. I did this measurement probably 4 times around all the ports just to make sure then made adjustments in my model


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

After printing up a couple spacers and test fitting until I felt I had the port timing just perfect I came to this for my BDC. These checks were done with a Malossi .5mm base gasket that was supplied with the case.


Here's a cool view in through the Exhaust port:


Feeling good about the way things were, I reassembled the case with all new bearings, gaskets, and seals. (even though the engine had never been ran, im just paranoid)


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Another of the case with crank in and Crushed Naturdays:


One of the case with piston in at BDC and wine (I think it was Martini brand):


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Now to get the jug onto the case and make sure all my measuring actually worked! Oh no I didnt dremel enough for the heads of the M7 bolts to the case, no worries! a little more dremeling and running 4 "troughs" down the skirt and it all was groovy! These skirts are super thick so i wasn't afraid to take some meat out.


Got the Cylinder on and the first full mockup with crank and piston in bolted together! looks good!! Still no idea if it will work but looks good!



Re: Stage6 MK1 Peugeot Engine

Totally normal JBOT /

That looks awesome.

I've been riding a scooter kit bike lately and it's hard to go back to moped cylinders after feeling the power of those kits.

Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

okay! got a spacer made and it looks great! time for assembly!


Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Jug on.


Chamber on.


Top On


Re: Stage6 MK1 Peugeot Engine

Totally normal JBOT /

Oh wow

Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Final check for squish comes in at .81mm Perfecto!


Looking down the exhaust


And sitting next to a Stage6 hobbit.


Next up is testing! Lee and I will get this engine on a bike in a few months and I will make sure it performs as intended before I move forward at all. If it performs great, I will release the spacer for the public. If it doesnt run, ill throw it in the garbage and try something else. Anyway, thats it for now until it runs. I hope you enjoy seeing the design process from start to finish for one small project and can appreciate the effort that goes into making new moped parts!!

Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Thanks man! I appreciate your support on these projects more than most! Always pushing to do more and go faster!

Re: Stage6 MK1 Peugeot Engine

I am terribly terribly impressed!

Re: Stage6 MK1 Peugeot Engine

rip dicks!!

Re: Stage6 MK1 Peugeot Engine

Awesome work.

I love these cylinders, the flange and long skirt make them so you can mount them on damn near anything! I stuffed a R/T 95cc into a Honda AF18 Dio engine... it is a monster.

Too bad they are out of stock on them most everywhere now.... have a hunch they may be discontinued for the flange mount style for RC-One cases... 30hp moped would be hillarious.

Why not just make cases though.. you have the design side down. Make cases that accept peugeot scooter parts or minarelli... then you can use all the wild stuff.

Re: Stage6 MK1 Peugeot Engine

Pritza R&D /

Yeah the long skirt allows you to really play with ports and deck height! It’s really cool, I wish other cylinders were designed like this.

I realy wanted to get one of those 95cc kits, if I ever find one not out of stock I will probably get it for a hobbit.

Cases are a possibility but I wanted to make a spacer so people can easily get this kit onto any aftermarket 103 case and save money. This engine isn’t cheap and is like $1000 added up, so to throw a $600 cnc case on top really cuts it out as an option for many people.

This spacer should work on malossi, polini, Parma cases with similar boring to what I did. I wouldn’t think stock us or euro have the meat for the transfers, but why would you, aftermarket cases are affordable

Re: Stage6 MK1 Peugeot Engine

Hobbit would be tough for the 95cc

I have stuffed a stock peugeot scooty crank in hobbit cases. It fits without issue... have to do some creative seal work and a new ignition plate ..... But for the 95cc crank you need a lot of meat in the cases to bore it out for the webs.... I don't think a hobbit has enough meat to do that stock...

... however I have some CNC hobbit cases I am designing that I left extra meat in the crankcase just for that reason... it's also flange mount so you can run RC-One flange mount cylinders. 2fast 100 FL anyone?

Re: Stage6 MK1 Peugeot Engine

That's my dream right there CNC hobbit cases for 95cc. Another option is to stroke out the stuffy crank for 44mm. Weld up the cases and bore it out.

@ crank works (edited)

Re: Stage6 MK1 Peugeot Engine

Great write-up!

Looking forward to testing.

Working on getting the test pug converted to water cooled with a malossi kit I had laying around.

The pug in question:


Re: Stage6 MK1 Peugeot Engine

Dirty30 Dillon /

This is great to see more people adapting scooter kits to variated bikes.

As with anything, I always worry about the longevity of the final drive components, which were never really meant to drive that power.

Specifically, the clutch pulley/pedal shaft of pug; the weak rear variator on hobbit; or in my case the transmission gears in my scooter-powered Vespa build.

I'll be keeping an eye on this, as well as Joel's other thread

Re: Stage6 MK1 Peugeot Engine

Making a launch lever and water pump bracket. Gonna trim up the aluminum then get something machine cut for a better looking finish.

Coolant hoses, and radiator attached. Even got to use a piece of copper.

And of course, beer to keep me going.


Re: Stage6 MK1 Peugeot Engine

That launch lever is upside down, you will have to lift it to get it to drop the belt down.

Re: Stage6 MK1 Peugeot Engine

Ha, yea yer right. Should be an easy fix, flip and adjust length as needed.

Re: Stage6 MK1 Peugeot Engine

Flipped launch lever, also used the stock (i think) exhaust mount to help dampen vibrations. Probably doesn't make a huge difference be it was convenient.

Got the bike running with the malossi LC 50cc. Doesn't look like any coolant leaks so that's good. Now I'll have to try to do a rough garage tune it since I'm out on MN.

Stsge6 engine should arrive tomorrow!


Re: Stage6 MK1 Peugeot Engine

love this. i like your deck height measurement. I'd done a buncha math a while ago trying to calculate it based on some measurements in order to compare what what swap to what, but if you're trying to make something just work, sharpie and measure top of piston at bdc to bottom of exhaust. nice! basically i'd sorta been considering "wrist pin height" - sortof a metric for how much space +/- is needed for a given topend on a given bottom end:

Re: Stage6 MK1 Peugeot Engine

The drink look delicious. One thing I’d like to see is the head squish band on that beast.

Re: Stage6 MK1 Peugeot Engine

Totally normal JBOT /

That mass of copper soldered abortion is so rough. Haha

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