On 10/19/2021 at 8:07 AM, polinist said:

welcome in GERMANscooterforum

Do you know the google translater?

I know google translator, but I also know how bad it is. Since most of the people can read english, I think it is better to simply write in english. Also since there is a lot of technical words when talking about tuning, google translator can really fuck it up badly and the whole sentence might become hard to understand.

 

 

On 10/19/2021 at 12:48 PM, Jimscoot said:

a couple of things that made a big difference was raising the squish from 0.9 to around 1.2mm

retarding the timing from 18 degrees to around 16 static.

then I was able to lean my jetting on phbh30

So what kind of improvements did this bring? Higher squish, more retarded ignition and learner carb setup... I feel like this made more power at the overrev?

 

 

Anyway, I am about to re-install my dear MHR. This time tho, I would like to test the VMC piston on it. Ring-pins fall in the 3rd port for both the cylinders, so no issue. I will use the VMC head to make sure it copies the vmc piston perfectly. VMC piston is about 1mm higher, so I will need to raise the cylinder 1mm to get the right squish and cylinder timings. The last thing that I'm trying to figure out, is the  tolerances. I live in a small city and its a PAIN to find someone with the tool to measure. I went to a workshop and they measured the following:

cylinder: 62.97
piston: 62.78

That gaves me a tolerance of 19 cent. What the hell? I suspect those values are not precise. Also 62.97 bore... that should not be possible, it should be 63.00 or maybe even something more like 63.03, if the coating is reduced a little bit. Also they guy said that the piston is not a cone anymore, because he got the same measure on 3 different heights of the piston.

So... all this makes no sense to me. I tried to find another workshop with the right tools, again it was a real pain, now I found it, I left them the cylinder and piston, but they are full of other jobs to do, it's been 1 week already and no news from them. The situation in my city is so sad... None does this "precision stuff" anymore, it's an art that's already dead, so sad.

Anyway: I will wait for news and then I will see if it is possible to use a VMC piston on the MHR. I'm not sure it will bring benefits of course, but I think it's worth trying.

Hey Giulio, i haven’t touched the ports in the MHR, just a polished exhaust port and slightly matching the VRone cases to the cylinder, that’s it. 
Out of the supplied base gaskets I used a combination of two to reach 0.36mm (measured with vernier) that brought my squish up to around 1.25mm. 
Timing is set to 16 on the stator. So at idle through to around 4000rpm I’m at 19 still giving me good torque but then pulling it back to around 14@7000rpm keeping it super safe while the expansion is super charging the cylinder 

The sip Camaro is a Masterpiece and compliments this setup perfectly.

The power is phenomenal, comes on song early around 5300rpm and pulls crazy strong through to around 8200rpm

Im using the Sip ultrastrong clutch basket with CR80 plates.

I’m using a combination of the XL and XXL springs but I’m detecting clutch slip so will need to go all in with XXL.

 

Did anyone here maybe measure the tolerances between piston and bore on the MHR?

Hi Gioulio 

Just wondering how your getting on with your Mhr? I had mine on the Dyno recently.

Viel beschissener kann man ein Leistungsdiagramm nicht darstellen.