PPMPR: Project Poor Man’s Pro Race

[toratora]

How did this bike come about? It's quite a Byzantine tale. Initially the engine was built up for the 05, and then later found itself in other bikes. Eventually into the first Track bike, which then became the Poor Man's Pro Race bike. At one point the engine had a MetraKit ProRace top end on it. When this failed they weren't so easy to source. At the time Treats was carrying a number of basic kits. The Airsal seemed like a good candidate for an experiment. That's how the story begins...

January 22, 2012

Metrakit Pro Race 48mm


Airsal Racing M 50mm 01083750


Malossie 50mm


Pro Race


Airsal 50mm


Malossi

I was hanging out at Treats and discovered that they had some kits for the Derbi EBE/EBS050 engines. There were three kits, two Airsal and one Malossi. I compared them to the Metrakit Pro Race known as the gold standard in Derbi top ends.

As it turns out the Airsal is extremely close to the Pro Race–that being the case it seemed to me that a project was at hand.

The large difference is that the Airsal has split exhaust port, and the Pro Race and Malossi have buddy/wing exhaust ports.

The Pro Race has a much large exhaust port making the other two look constrained. The wing ports on the Malossi are tiny–with a bunch of work they could be opened up, although stock it looks like they wouldn't have much effect. Additionally, the timing of the ports of the Airsal and Pro Race were very similar.
.

Pro Race


Airsal


Malossi

Now lets check out the case transfer ports. The Pro Race has gapping case ports–they are huge. Now in fairness the Airsal and Malossi are 50mm bores and that restricts the size of the case ports by an additional 2mm over all (one per side). Although I was already leaning this is what convinced me to go with the Airsal for this project.

The Malossi transfer ports are tiny, especially the rear port–one wonders if anything would even make it through that misrepresentation of a port, and the side ports are also much smaller. They could be worked open however it would be a lot of effort, and the Airsal ports measure close to the Pro Race (taking into account the wider bore of the Airsal) and will need little if any mods.
.

Pro Race


Airsal 50mm


Overlaying of the Pro Race and Airsal

Here are some port mappings of the Pro Race and Airsal.

The rear transfer port on the Airsal is shorter and skinnier than the Pro Race–unfortunately the pin on the Airsal piston is placed close to the rear port leaving no room to widen it, although it could be modified to the lower height of the Pro Race. Now there is lots of material back there with which to work, and to do so could be enabled by moving the ring pin towards the rear side transfer port. This would allow for a widening of the rear port.

The Airsal already has wider rear side ports than the Pro Race. These ports should be less wide than the front side ports so for this mod we would want to leave these ports alone. Of note and this is true of all of these kits–the forward side ports angle the fuel up and towards the center of the cylinder, and the rear side ports aim the fuel orthogonally into the cylinder aimed at the exhaust ports.

Overlaying the two illustrates the similarities.

The timings are nearly identical. The area of the exhaust ports is quite similar. I did some math and found that the Airsal is about 1/10th lacking the area of the Pro Race–the top of the Pro Race is slightly higher and its wings extend to a greater width. Careful opening of the upper width of the Airsal could bring this into parity.

The one issue here, and it's a main advantage of the Pro Race kit, is that the ring travels across two bridges of the wings with the Pro Race and only one for the Airsal. When things heat up that single bridge expands and can apply a pressure on the ring. Some tuners deal with this by slightly bowing the bridge away from the piston so than when it heats up and expands it moves into its proper place–something to consider.
.

Airsal Xtreme


Wider exhaust port

Airsal does make a kit that is even closer to the Pro Race called the Xtreme. It has more aggressive exhaust, and rear ports (yeah there are three rear ports compared to the single on the other kit). Malossi also makes a high end kit, however the pricing of it is such that you are in the same budget as the Metrakit Pro Race.

The Xtreme kit is priced well below both the Pro Race and the higher end Malossi kits. The main reason for the cost differential is that the other high end kits have modular head designs which allow water to flow completely over the head affording better cooling. The lower end Malossi, and the Airsal kits employ a uniformed head that incorporates the cooling channels in a single piece.

The Xtreme exhaust port is much wider.

Okay that's the opening post–depending on the rain and how aggressive the classes are this semester will determine how quickly this project will progress. I'm excited about it. : )

[toratora]

January 23, 2012

I got rather excited writing about this project last night and since it has been raining here in SF and I had a bit of time this morning I decided it was time to port.

I had to do a bit more data collecting. Here's an EBS050 engine with a Pro Race base gasket on it. Notice that the cases cover up much of the Pro Race's ports. To do a proper job of it the cases would need to be opened up. That's not going to happen in this iteration, however expect it in the future.



Here's the gasket on the Pro Race



And on the Airsal–the Airsal is actually close and little material will need to be removed to match it up to the Pro Race.



Marking up the Airsal for material removal







The exhaust port is where I intend to do most of the work and as such it was time to do some measurements. The Pro Race as it turns out isn't round. It is an oval shaped hole that is wider than it is tall–about 28mm wide and 26.5mm tall.





The Airsal is round at about 25mm



Here is the intended removal area marked out



Marking out the exhaust port



I really don't have the best tools for this kind of work–one could say that what I have sucks. Still it is what I have and what I'll employ for this task. I have on older battery powered dremel that Eliot gave me (this actually works quite well) that doesn't have a battery charger. I was able to employ one of the programs in the Ballistic super charger. The dremel works well however the battery does run out quickly for this task I had to recharge it about 4 times. I also this Chicago Tool rotary tool that I bought at Harbor Freight. I use this mostly for grinding. In this photo the grinding wheel is nearly used up. Because of the low speed it is easy for this tool to jump and muck things up. This happened a few times on this outing.



Here is the dremel fitted with a carbide bit



The results of the porting



















I also needed to match up the exhaust manifold for the Ninja pipe–it has a larger piping than the stock pipe however it is constrained through the manifold mount so I ground a bevel to help with the flow.





Lots of material removed today!



The next step is fitting it on the bike!

[toratora]

January 28, 2012

I started off by learning how to polish aluminum. It turns out that wet sanding with a coarse grade, then a fine grade, and then followed by a polishing well with a couple of different rubbing compounds is the process. I started out with the sand paper.

I used the Dremel with a sanding wheel to even out the cutting tool marks. Then I started in with the sand paper.



I only made it to the second step of sanding with the 150 (coarse grit)



With hours of going at it I made it through most of the sanding at this level, there are still a few spots that I hope to finish up.



Here's the before



and the current state





It is ranther difficult to photograph this stuff with just a phone and show the little details, however from here you should be able to see the sanding grooves.



These will become less so once I move onto the finer grit.

[toratora]

January 30th, 2012

Had some more time to work on the bike today. I started out by continuing with the sanding action. I was running out of time so there is a little bit that if this were a race bike I'd probably sand out the last little bits. Because I wanted to get the bike on the road today I switched over to the 1000 grit and got in some action. The next step would have been to take a polishing wheel to it. The surface came out smoother than any of my other bikes so I'm okay with how it came out. My fingers however are sore and have open areas from the constant rubbing against the exhaust port center beam.













As I would sand I rinsed off the sandings and cleaned out the paper–while doing this I noticed I could see the flow of the ports. These are some lame attempts at capturing the flow.















Here are the Pro Race piston (the smaller one), and the Airsal piston. I would have liked to weighed them to find out how much heavier the Airsal was compared to the Pro Race, however I didn't have the ability to weight them today. I was somewhat concerned because when I employed a heavier piston in the Mito there was a lot of vibration involved.







There was only one gasket with this kit–which could have been an issue with the squish–thankfully it wasn't. From this photo it is clear that the gasket is just a generic gaskit not even cut to fit the stock Airsal, and would need some fixing.



With the fixes



Checking the ring gap



Just before the top of the exhaust port I found the piston hanging up a bit, just above is this photo



And here where the piston is as the ring hangs up a little bit



Time for assembly and that means coating everything with a thin layer of engine building lube. Here's a trick I learned from AJ. I use to use the 1348 sealer, and it works great however it kills the gaskets when you open up the engine. So now I use the engine building lube. It works great, and doesn't kill the gaskets.



New wrist pin bearing-setting up a rag to keep any thing from falling into the engine cases.



Inserting the first clip and placing the piston in the cylinder



Sliding the barrel on the studs



Then time to put in the second clip. I know Chris likes these kinds of clips–for me I hate them. This one bent while putting it in. So I ended up getting one from another top end that fit well.





Barrel in place



Employing the engine building lube to keep the rubber o-rings in place





The head–I didn't do anything special with it this go around.



Laid a bead of engine building lube to holding the rubber gasket.



Head on–I'm a big fan of the 1/4" drive for these tight space jobs–the head nuts are 12mm



Torquing it down (I think it is ~19N/m, however I have to look that up)



Checking the Squish–it should be around .04" and the .05 solder works great for this task



Cut off a piece and make a loop



bend a bout a 90° corner so that you can reach into the squish part of the cylinder and place it in the plug hole, turn the engine (this can be done by putting it in second gear and spinning the rear wheel. Pull out sold older and take a look. It should be flattened out just a little bit.



Then you measure it–looks good!



Prepping the exhaust with copper silicone–this is another trick I learned from AJ!







After that in was button things up, and do some heat cycles–although it did get a bit dark for photos. I did three of them each time bringing it up to temp (I installed a nifty temp sensor which I'll have to write up). The first time to around 63°C, then 75°C for the second two. The third one I had to mellow out because it was getting late so I just let the bike idle for about 20 minutes. Then once that heat cycle cooled down back to 12°C I went off for a little ride.

As I had feared the heavier piston does cause it to vibrate much more. There is a lot more low end power than the Pro Race kit had which is probably due in part to the larger boar. Being new I didn't really take it up to being on the pipe, because that starts at 10,000RPM, however I did let it get close and it wants to go for it. Once I get enough miles on it then I'll open it up and report.

[toratora]

February 17th, 2012

Today I had a chance to pop the top off and take a look. Here's what I found.

The chamber suffered some scoring on the edges of the exhaust.





There was also some scoring on the rear port.



On the piston I found scoring from the rear port,



and the exhaust side.



To addresses these issues I performed a more aggressive chamfering, and some work on the piston. I had read on Moped Army about placing some holes in the piston in the same vertical plane as the exhaust bridge helps to lubricate the bridge. This sounded like a good idea.

Marking the placement of the holes.



Holes drilled and chamfering started (I tried to drill out the holes with the Harbor Freight tool. Even with center punched starts the HF tool just spun out. Since that didn't work well, so I got out the drill and did it proper).



Then it was time to address the weight issue. This piston is significantly heavier than the piston in the ProRace kit. I really need to pick up a scale for this work. I did an impromptu knife edge balance and found that the Airlsal weighs more.

Places that I've successfully removed materail from pistons includes certain sharp edges:



Here's the piston after having removed some material. A second weighing indicated the Airsal piston (made by Vertex) still weighs more, however that was expected since I removed little. I also chamfered the entier skirt area.





Another issue I addressed was the wrist pin bearing. I had purchased a Gilardoni bearing and that fitted a bit tight. I though that may have been responsible for some of the vibrating I was feeling from around 6 to 9k. I'm sure weight was at least a partial contributor, however that bearing seemed just a bit too tight. So I picked up a Top bearing at Treats.





Putting things back together...





The plug looked pretty good:



Once it was all back together I did a couple of heat cycles, and then took it out for a test ride. The vibrations are significantly less than before and once the bike gets on the pipe it is on the pipe it gets even smoother–it screams quite well. As the kit runs it I feel it getting stronger and the bike pulls strong well above redline. I'll be giving it some more riding before I can give it an all out test. For now it has more midrange than the Metrakit and it looks like this modified Airsal is going to challenge it on the top end.

[toratora]

June 13, 2012

Nor*Cal Cycles held their annual BBQ Dyno Day, and I took the GPR down there to see what it could do. Over 12 HP—pretty nice all things considered.





https://www.youtube.com/watch?time_continue=1&v=XuuxgLZN3VU

[toratora]

The engine would run in the 05 GPR for some time to come, until it was replaced with the 88cc Xtreme Airsal build that turned into a total nightmare. The PMPR engine would then find a new home in the Red bike—probably my best build at that point in time. The Red bike set a new level of accomplishment in both quality, and performance of my builds.

July 19, 2013




During this time I was building up another bike, that would eventually become the Track bike. While this version of it never saw completion, I still think the blacked out frame, swing arm, and other components with the 2000 blue plastics have the potential to look way sexy.

July 3-16, 2013














Due to a number of unfortunate events the Red bike was taken off the street, and most of the parts would be deployed elsewhere. Many of which would find their way to the Track bike. Including the PMPR engine.

February 16, 2015


August 12th, 2015

[toratora]

In December of 2015 we took our track bikes to the Nor*Cal Dyno day. Here the PMPR produced nearly the same HP as when it was in the 05 Black bike. Very close to the previous run. Slightly less power, but there are a number of things that could explain it.

December 5th, 2015

[toratora]

April 19th 2017

The Track bike is currently fitted with the HPI mini rotor. This is a great ignition, but it does't have an accessories circuit, and the one that they sell for it is a total piece of garbage. Since the track bike is going back on the road for GPR Camp I need to fit it with a different ignition. But once you have a variable curve you just can't go back to a static curve. The solution? Well there were a number of them, but what did they have in stock at Treats? The Top Performances 9921690 Red Box.

Now most things you will read for this unit state that it's for the AM6, but that is qualified by Top when they say AM6 type engines. Well that's good enough for me, and when you consider that the Red box is designed for the Top performance top ends (yeah I know that's a bit hard to parse!), that the Derbi employs the same Ducati ignitions, and some of the CDI units sold for these bikes are marketed to both bikes I figured this should work. And if it doesn't them maybe I'll have to get another RS50 down the line.

In all the photos I've ever seen of this unit I've not seen the back of it--which is just a potted box with wires coming out. Not so clean looking compared to most CDI units. It's actually kind of shoddy looking considering how expensive this unit is compared to other units. I'm going to have to fab up a mounting bracket since the older GPRs really aren't set up for this sort of thing. It actually would be pretty easy to mount this in the 2005 because that is set up better for a two part system. The HPI unit comes with a bracket for the coil, but the Top doesn't.

Some of you are probably wondering why I didn't just get an HPI 2Ten for this bike since I'm running them on some of the other bikes. Part of the reason is that I've never (and yeah I mean never) gotten a 2Ten to run correctly, or satisfactorily, and the other reason is when I did try to get one for this bike they didn't have any in red. The gold ones look way to garish, and the black ones, well I suppose that would have been okay, but really I wanted a red one. I still make install a 2Ten later down the line when they have red ones, and then maybe move this unit to another bike.

There is one advantage of using the Top unit over most other vectors and that is you would still be able to use the electric start since the Top unit employs the Ducati stator and flywheel. Still there are caveats. I can't seem to find it tonight, but I remember reading that this unit doesn't work with stroked cranks. So if you don't have the 40mm crank in the engine you may not get away with using this CDI. I don't know why that is, and that's something for me to research in the future, and the future is now.

Unrestricted digital CDI with variable ignition point
Info:

CDI box with ignition coil from the Peak Performance with variable ignition point.

A brilliant product for anyone who wants to upgrade his bike and does not want to replace the entire ignition system, and keep the ignition is set manually.

The CDI box has been designed for the Minarelli AM6 engine that has the 6-spoliga Ducati ignition plate, but also works with the Derbi ignitions which have the 6-spoliga Ducati ignition plate.

When the original CDI has the same ignition point through the entire registry to have Peak Performance have developed this product which has an internal microprocessor which allows the spark advance is adjusted automatically, the more revolutions the motor has, thus optimizing the ignition point.

The CDI also has a very good lighting control called "Power Control", which ensures that pre-ignition is prevented, resulting in that you get a cleaner ignition.

The ignition control also ensures that you get a longer life for both ignition systems and spark plugs.

The other major advantage is that fuel consumption is reduced and this also includes air pollution.

This kit contains the following:
1 st - CDI
1 st - Ignition coil with 5 kOhm primer + cable
4x - Kardborrebitar for mounting

NOTE! This product is intended to be combined with Top Performance 70-75cc cylinderkit in their Redline series but can also be combined with equivalent cylinderkit.

IMPORTANT NOTE! This CDI kit is not intended to be used with the kits in 85cc class, or cylinderkit with extended stroke as this can cause damage to the ignition, and the cylinder to seize.

While the directions come in a metric shit ton of languages reminiscent of a Japanese pocket radio, or shaver, there is nothing about the actual ignition curve for this unit. This kind of, no this totally sucks with regards to tuning the bike. I guess they just want to to bolt it on and go. The only method one would have to adjust it would be to run the flywheel without the woodruff key and adjust it from there. This is basically what you do with the HPI units, and of course the stator plate has a small amount of adjustment. But since you don't know the curve the only way to know is to put a timing light on the unit, and most timing lights don't track at 10K plus RPMs. Pain in the ass desu.

And of course if you go searching the web for information about this unit you end up finding what I've already posted. lolz

However, the clever cats at RRD have posted some information that points to the answers:

This kit is intended for engines minarelli am6 equipped with a lighting of origin DUCATI, following our tests, laying on DERBI not hurt anything! The power gain feels from 7600 rpm and this kit allows blithely exceed 16,000 rounds against a clamping or malfunction 11 000 see 13,200 rounds of ignition source according bikes, this kit really allows full advantage of the large kits , their powers and their times. for this plant, TOP PERFORMANCES has developed a curve and special mapping to make the most of the engine power especially at high speeds. The CDI unit has a microprocessor on which the mapping is stored, this allows for a modified spark advance according to the variation and the number of engine revolutions.

The advance self shifts backward to the couple and low speed forward has high revs so that the engine can take endless towers .... A huge power won face a fixed beforehand, the fixed advance does not allow you the maximum power for the spark always come at the same time (advance remains the same) despite the number of revolutions per minute, however an engine demand more or less in advance by his regime. In addition, TOP PERFORMANCES has still pushed further this pack by opting for a high ignition coil separate and reduced voltage, this offers less ignition heaters, improved mass and an additional power spark. The high-voltage wire in the Box is a high-end cable, more TOP PERFORMANCES added parasite competition without resistance. What have a really powerful and ultra strong ignition, torque gain is really felt and gain high / midrange is amazing!

Remember, once the kit installed, use only gasoline SP98! More SP95 which could generate rattling! This pack is not to be used with the kits TOP PERFORMANCES 85cc and 86cc without removing the staggered wedge ... At high speeds you would too far ahead, this will create overheating and tightening risks. A beautiful pack of variable advance TOP PERFORMANCES RACING.

I also found this graph for the Top Performances 9909300 CDI unit that can be fitted to older RS50 machines.

[toratora]

I really dig the added performance from my Red Box CDI.
Also liking the extra tech you managed to dig up on it, consider it saved.
RS_Patrick posed this awhile ago, I have not had the time to verify it.
Maybe you can.


Would like to get your feedback on your experience with this CDI once fitted.
Top also sells an Offset Key (6 or 7 degrees), wondering if it is the "special one?"