Malossi MHR 177 - Die neue Legende

[wasserbuschi]

Denke auch, dass mit den Zeiten und dem Atom exakt das gezeigte Ergebnis zu erwarten war. Bzw. hätte ich sogar in der Kombination weniger erwartet. 

Da mal einen neuen RAP drauf und dann geht da nomal was! 

[Schindluder]

Wer braucht schon Drehzahl wenn vorher schon genug Druck anliegt 

... da geht doch nur wieder was kaputt. 

 

Genau bring ich’s natürlich nimmer zam. War das ein „Drehzahl“ oder „Drehmoment“ Bausatz?

Wird vermutlich schnell klar wenn du mal ne Referenztröte dran steckst.

... aber für 25,- ganz ok oder? 

Bearbeitet 29. Juni 2020 von Schindluder

[scooterboy86]

vor 6 Stunden hat Schindluder folgendes von sich gegeben:

 

... aber für 25,- ganz ok oder? 

absolut Geil! 

[Scharpe]

Bei dem Eigenbau Atom geht mir aktuell einfach total einer ab  

 

Klingt genial, garnicht so laut  und durch den gedrehten Dämpfer optisch perfekt für den Hobel. 

 

Bei Zeiten und Geilheit stecken wir auch mal ne aktuelle Referenzanlage drunter 

[Humma Kavula]

Ich hab auch mal einen fertig gemacht, Zeiten liefere ich nach. Ist für nen Kumpel, dauert noch, bis das Ding fährt. Roller ist noch nicht zusammen... 

 

 

Sprint 3 Kanal Motor, 60mm Hub, 26er SI, S&S Newline, 200ter Lusso Getriebe, Cosa Kulu mit Ring

 

Gruß, 

Humma 

 

[geoelter_blitz]

Am 9.11.2017 um 15:49 hat Marc Werner folgendes von sich gegeben:

Ich sage einfach mal ins Blaue, dass der 177 MHR aus dem Karton raus genauso Potent ist wie ein M1X. Heißt mit 30er, Membran, 57er Hub, Scorpion gesteckt auf Anhieb 22-25 PS. Potential nach oben vemrutlich ähnlich wie M1X (45 PS +). Warum mein einen MHR kaufen sollte und keinen M1X ? Was der 177 MHR besser kann ?  Keine Ahnung :)

kann mir das jemand beantworten?

[Marc Werner]

vor 10 Stunden hat geoelter_blitz folgendes von sich gegeben:

kann mir das jemand beantworten?

12 Einträge über Dir, noch auf dieser Seite ist ein verlinktes Leistungsdiagramm mit einem gut aufgebauten 177 MHR auf Drehschieber mit 25 PS (Zylinder unbearbeitet). Das entspricht aber von der Leistung her noch nicht der Regel für "Stecktuning" bzw. ist sicher auch stark von der Feinabstimmung und Komponenten, d.h. Auspuff, Kurbelwelle, Vergaser, Lüfterrad/Zündung, Einlassbearbeitung etc. abhängig. Gesteckt mit Box Auspuff, 57 mm Welle und SI Vergaser wirst Du dann wohl eher 14-17 PS haben. Kurz gesagt ist eine pauschale AW auf Deine Frage nicht so ohne weiteres möglich. - Was der 177 MHR besser kann, als der M1X ? Ich würde sagen gar nichts. Ich halte den M1X für deutlichh leistugsstärker (vor allem mit Potential nach oben), aber auch teurer. 

Bearbeitet 1. Februar 2021 von Marc Werner

[stoschi]

Moin,

muss das alte Ding mal vorholen.

Bekomme den Kopf des 177er MHR nicht dicht.

Habe am Kopf einen 1,5er Spacer um auf die richtige QK zu kommen. Sieht für mich so aus, als wenn der O–Ring nicht dichtet.

Der Spacer ist minimal größer im Durchmesser als der Zylinder.

Gibt es die O–Ringe einzeln?

Gibt es da bessere Köpfe für? Finde nur bearbeitete Malossi Köpfe für andere Zylinder.

 

Bearbeitet 18. Juni 2021 von stoschi
minimal größer nicht kleiner

[wasserbuschi]

Spacer kleiner im Durchmesser als der Zylinder? 

 

Dann überleg mal, wo der Hase im Pfeffer liegt.... 

[stoschi]

Sorry verschrieben. Der Spacer ist minimal größer vom Durchmesser.

[JungSiegfried]

falsches topic, sorry.

Bearbeitet 19. Juni 2021 von JungSiegfried

[zimbo]

https://www.sip-scootershop.com/de/product/rennzylinder-malossi-mhr-177-ccm_31171630?q=mhr

 

wie der 200er auch mit geschraubtem Auslass....

 

 

[orpheus]

Hä? Das hatte er doch schon immer …?

[zimbo]

Ups 

 

irgendwie nicht aufgepasst 

 

dann hats jetzt der 200 er halt auch 

[GiulioEX125E]

Hi everyone. I'm Giulio from Italy, I don't speak German so excuse me if I don't write in deutsch.

It seems to me that the 177 MHR isn't getting much love. I think it is a very good cylinder design, but I haven't tried much else so I really can't tell.

I just want to give you my experience regarding MHR 177, maybe it can help someone. I am sorry in advance, this will be a damn long post :)

 

So at first, I had this setup, which I call STEP 1

-MHR 177, 120-174° (standard timings), squish 1.0, CR around 11 or 11.5:1 I don't really
remember
-57x110 Tameni full circle crank -LML cases with intake heavily opened (in the pictures
you will see Weicon resin
used, but after a while that started to leak air so I just removed it and welded the cases)

-vforce4 with phbh 28

-Pinasco 1,6 kg flywheel on original Ducati ignition, 18°
-22/64, 16-19 cluster, z35 4th gear

-A LOT of exhaust tested, I just list the ones that performed the best with this setup: for the boxes Megadella v5cl3, Megadella XL, Faco Racing; for the expansion exhaust 2L Tech Bazooka, Sip Performance 1.0, Pipedesign Bullet M1X

 

 

So this engine was quite good, it was my first experince with reed valves and it was performing nicely. My previous engine was a rotary VMC Stelvio, and this reed MHR was quite better, especially at peak power and overrev.
I will leave here some graphs with the exhausts that performed better with this setup, STEP 1.
Overall the peak power/torque was always around 22hp and 21nm.

 

 

I noticed that all the expansion exhaust performed worse than the "similar" box exhaust. Box showed no pre-reso hole, very similar peak power, maybe just a little less power in the overrev, but not so much. Also boxes are way cheaper in price, and way more quiet in sound. So I just tought that with this setup, box were basically overall better, probably because of low timings.
The last exhaust I tried was the PD Bullet M1X, which I bought new and I had GREAT EXPECTATIONS for, and the Megadella XL. So after some months with this MHR step 1, I decided to go for the STEP 2, mostly to give the PD Bullet M1X better timings, closer to the producer recommendations.

 

 

So here is the STEP 2:

-MHR 187 (native 57mm) with 60mm stroke Tameni crank, not full circle
but rotary valve type, 60x110 127-190° timings, 1.0mm squish, 13:1 CR
-PWK 32 on vforce4
Rest was exactly the same as STEP 1.

 

The gain in performance was HUGE! Starting from the 22hp of the step 1, I was hoping to get around 25-26 hp, instead GSF Dyno showed 30 hp! I was shocked, and on the road it felt like a whole different engine. At the bottom end I lost very little, this can be explained by the longer 60mm stroke. At peak and overrev the gain was impressive. It was a damn great engine to run, funny as hell, I loved it!

 

 

 

But but but... here comes the sad stuff.

1) 420€ PD Bullet M1X performing way too similar to 220€ Megadella XL. One had toruqe at lower revs, one at higher revs, but the peak power was around 30hp for both, and that makes no sense for me, either the PD Bullet M1X wasn't good, or the Megadella XL was TOO good for the price. This engine with the step 2 had all it could need to make an expansione exhaust perform better than a box: high timings, reed intake, big passage from the reeds to the 3rd cylinder port in order to pick up the exhaust signal, etc. I just came to a conclusion that even with higher timings and all the other things I just mentioned, box exhausts are overall better than expansions! Maybe the PX engine just doesn't work too well with expansion exhausts and goes really really well with boxes, for some reason.

 

2) this beast of an engine, only lasted 2 weeks, sadly. The crankshaft got twisted, probably because the 60mm stroke cranks have a smaller 20mm conrod pin, instead of the bigger 22mm of the 57mm cranks. I had to split the cases open again, and remove the 60mm crank.

So at this point, because of a lack of money and time, I was forced to use again my previous crank, 57m stroke full circle. Sadly, since I manually raised the exhaust port in order to reach 190° with the Step 2, now with 57mm stroke I have 120-187° timings.

 

And so here comes the "step 2.5" which was a total failure. 120-187° just doesn't work, it has too much differential between transfers and exhaust. Peak power was decent but torque curve kicked in soooo late, around 5.5k rpm even with Faco box (99% similar to Polini box, which has plenty of torque early at low revs). This is a comparison between step 1 (120-174°) and step 2.5 (120-187°), as you can see, the powerband became way too narrow, way too late to kick in, and only gained a small amount at peak power.

 

 

So yeah, step 2.5 was quite bad. I tought that I just ruined the cylinder by manually raising the exhaust port so much. I just took the MHR off, and I installed the VMC Stelvio that I had from the previous engine. I took the chance to make a comparison with VMC Stelvio and Malossi MHR, both iwth standard timings 115-170° vs 120-174°), on the same engine. Surprisingly enough, the VMC performed better than the MHR with the Megadella XL.
 

 

 

The good low-rpm  torque of the VMC, combined with the good overrev of the Megadella XL, gave a nice result I think, 23.5 hp and 23.8 nm, 10k rpm with standard 170° exhaust timing, is quite impressive in my eyes.

But... I just didn't want to give up on the MHR. Also the VMC piston is quite noisy under 3k rpm and I really hate it, even if the cylinder is performing really good.

So after some weeks of hard thinking... I decided I wanted to give the MHR another try. Instead of trying to lower the exhaust to get a smaller differential, I just said fuck it, lets raise it to higher timings, lets make this MHR the way it is supposed to be. The only sad thing is that I still have no money for better parts, so I am forced to put something together with what I have at home right now :) So here it goes!

 

 

STEP 3
-MHR 177, 130-195°, squish 1.0mm, RC around 11.5:1

-exhaust width still stock, quite small to be honest, with around 70% width on a bridged exhaust. I will gradually widen it to 75/80/85%, which is the max you can do without breaking on the cylinder studs

-57x110 full circle crank, hope this time the 22mm conrod pin doesn't twist!
-28/32/34mm carbs will be tested, vforce4 reeds
-22/64, cluster 16/19, z35 4th gear; this will probably be a little long but I can't go with a z21 sprocket since I have a 8 springs clutch and z21 doesn't exist for 8 springs clutches
-2,1 kg elestart flywheel on static Ducati ignition 18°
-I sold most of the exhausts, the best I have for this setup is a BGM BBS, which I modified on the interior, looks like I gained 3-4 hp over the whole rpm range, but I have to do another GSF Dyno run to confirm.

 

 

So yea...  this will be step 3, doesn't look great but if I can get close to the 30 hp of the Step 2, I will be happy enough, and this time I should also have some reliability with the 22mm conrod pin, hopefully not twisting the crank again.

 

My big ass story ends here for now, wish me luck 

Bearbeitet 25. September 2021 von GiulioEX125E

[Friedi]

Giulio,

thank you so much for investing so much time into creating this long and intensive article.

This will help a lot of people in their planings for their personal projects. 

[style63]

Did you do a GSF-Dyno with MHR and BigBoxSport?

[GiulioEX125E]

1 hour ago, style63 said:

Did you do a GSF-Dyno with MHR and BigBoxSport?

 

Not yet, only with the VMC with standard timings. And it performed quite poorly to be honest...

Setup is written above the graph. Faco Racing box is 75€, BBS is 180€ 

 

 

Based on my experience, exhaust can change their performance a lot based on the rest of the engine setup, especially cylinder timings. So I'm curious on how the BBS will perform on the MHR with higher timings.

I already opened the BBS and modded it a bit, you can check the details here:

 

On the road it seems to perform quite better now, also did a GSF Dyno test which showed good gain on the whole rpm range BUT it wasn't on the road where I normally do the runs, cos I got lazy and I just went to another road way closer to my house 

So yeah, I will have to do a proper run on the usual road, then I can post some before/after graphs.

[style63]

My experience with BBS an low timings was similar. 121/174 did  better and hold power to 8000. But the performance at the important range around 5500 rpm remained poor.

 

I have a modded one too. That solved the overheating issue. But until now SiP Road 3 gains better results. I am curious about the result with your higher timings. Next step could be fitting a better difusor instead of the long header pipe.

[GiulioEX125E]

1 hour ago, style63 said:

I have a modded one too. That solved the overheating issue

To be honest, I had no temperature issues with the original BBS, even with the 16,5mm outlet pipe it has. My sip sensor (under the sparkplug) showed the usual 120-130°C. Even after modding the BBS with a 20mm outlet pipe first, and 18mm later, it didn't change anything about the temperature.

 

Anyway yea, this BBS looks pretty bad in my eyes, at least for now.

75€ Faco box = full low revs torque, no high revs torque, feels like hitting a wall

180€ BGM BBS = little bit less low revs torque, but in the overrev area it goes more freely, doesn't hit a wall

220€ Megadella XL compact = has even less low revs torque than the BBS, but at peak and overrev it is just a monster, even with stock cylinders and 170° timing.

 

So in my eyes, the BBS is a good balance point between the Faco (or Polini Original) box and the revvy Megadella XL, BUT the price should be more like 130-140€ rather than 180€. Also considering that:

1) manifold stripes in right curves, I still never stiped it but it might be that I dont drive so hard, on the internet you find a lot of pictures of BBS striped on the manifold so it is for sure too low

2) internal wall tend to fall apart and rattle, with the need to open the box

3) the holding brackets (the one linking the box to the engine swingarm I mean) also tend to break

 

Sooooo yea, 180€ for all this, wtf? :D

 

 

Bearbeitet 26. September 2021 von GiulioEX125E

[style63]

You have interesting results. But i think that this configuration is not a good set-up for BBS. I look forward for your runs with higher timings. 
 

On the other hand Polini Box and SIP Road 3 run very well with nearly every set up therefore it is questionable to tune a motor for BBS. But i think tasks like this are what makes our hobby that playful. :)

 

About the overheating: it is a motor with more than 26PS/29nm and high compression. I think that this tends faster to pink than a 21PS unit.

Bearbeitet 26. September 2021 von style63

[GiulioEX125E]

I figured out in my long ass post, I didn't post a comparison between step 1 and step 2 of the MHR.

While reading all the 35 pages of this topic about MHR, I've read that a lot of people are quite dissapointed with the cylinder, because it doesn't pull out the expected power.
But I think of it in a different way...
Most of the setups I've seen in those 35 pages are soft-tuned, some have rotary intake, some have low cyl timings under 125-185°, and NO ONE has a widen exhaust port. We're talking about a bridged cylinder, that comes with a 70% exhaust width. Why would you take a bridged cylinder and use it with a 70% exhaust width? Makes no sense (and keep in mind I still have it at the original 70% width, but I think that was a mistake from me, to raise the timing BEFORE trying to widen the port).
And also: why use an MHR for a soft-tuned engine, when there are better options, like VMC Stelvio or Quattrini M1X? What I mean is, 2 exhaust types, one single port one bridged port, if both are at 70% width, the single port will flow better I think, because the gasses will not be divided in 2 by the bridge.

In my opinion, if you want a soft tuned engine, that pulls a 23/65, that has early torque, that works with low timings, then get a Malossi 177 sport, or a VMC Stelvio, or a Quattrini M1X that are the best options, in my mind.

MHR means Malossi Hyper Racing. Not Malossi Soft Tourer :D

 

So give it what it really wants! Give it 130-190°, give it an 85% wide exhaust port, give it a 38mm carb on a huge reed block, give it an exhaust that comes into resonance at 5.5 - 6k rpm, give it a 22/68 primary with a short 3rd and 4th gear cluster! Then we will see the true face of this 177 MHR. I might be wrong with this way of thinking... but when I went from step 1 to step 2, the torque I lost at lower rpms was quite small, and the power I gained at higher revs was HUGE.

As I said, I forgot to post a dyno of step 1 and step 2, so here it is. Step 1 with PD Bullet M1X and Megadella XL, vs Step 2 with the same 2 exhausts. Check the difference and tell me: does this MHR work better with standard timings or with much higher timings?

 

[Quick recap]

 

STEP 1:

177cc with 120-174°, squish 1.0mm, CR 11.5:1, 70% exhaust

full circle 57x110 Tameni crank

phbh 28 on vforce4 reeds

1.6k flywheel on ducati 18° static

 

STEP 2:

187cc with 127-190°, squish 1.0mm, CR 13:1, 70% exhaust

rotary valve crank 60x110 Tameni

pwk 32 on vforce4 reeds

1.6k flywheel on ducati 18° static

 

Bearbeitet 26. September 2021 von GiulioEX125E

[Jimscoot]

You will only see the full benefit of the mhr177/187,

Once you step up to VRONE cases and vespower ignition.

30phbh and a torque based expansion, Sip Camaro as an example 

 

Bolted onto these cases you won't need to mess with cylinder timings, just ignition timing and jetting

 

 

Bearbeitet 18. Oktober 2021 von Jimscoot
Mistake

[GiulioEX125E]

16 hours ago, Jimscoot said:

You will only see the full benefit of the mhr177/187,

Once you step up to VRONE cases and vespower ignition.

30phbh and a torque based expansion, Sip Camaro as an example 

 

Bolted onto these cases you won't need to mess with cylinder timings, just ignition timing and jetting

 

Well... VRONE cases surely are nice, with a good intake even if not optimal (ooptimal = bfa intake style, carb pointing backward and reeds pointing forward). Vespower ignition, I dont know, 1.2kg flywheel sounds a little bit too light, considering the lightest largeframe clutches weight around 1kg (Crimaz) or 1.3kg (Sip or standard Piaggio) so its 1-1.3kg on the clutch vs 1.2kg on the flywheel... I dont like that.

 

Anyway, my MHR with stock timings, on LML cases with the intake opened up and a fullcircle crank, with a phbh28 on vforce4 reeds and various box and resonance exhausts, pulled around 21-23 hp and 20-23 nm. Did  you get better results with your setup? Did you dyno it already?

[polinist]

@GiulioEX125E @Jimscoot - welcome in GERMANscooterforum

Do you know the google translater?

 

[Gast]

Dear @GiulioEX125E @Jimscoot 

 

of course you are very welcome to this forum. 

 

Please feel free to share any further thoughts and experiences with us regarding any topics related to vintage Vespas 

 

Your posts until today are very interesting and mind refreshing to get this expensive piece of Malossi aluminum in better operation then my friend @Tyler Durden and myself were able to perform 

 

 

Any Person which is able to read this should have the competence to copy paste any posts if needed for understanding to let google or any other services translate 

[Tyler Durden]

vor 8 Stunden hat GiulioEX125E folgendes von sich gegeben:

Anyway, my MHR with stock timings, on LML cases with the intake opened up and a fullcircle crank, with a phbh28 on vforce4 reeds and various box and resonance exhausts, pulled around 21-23 hp and 20-23 nm. Did  you get better results with your setup? Did you dyno it already?

das ist ja mehr oder weniger das was wir damals auch raus hatten, mit ähnlichem Setup und verschieden Auspuffvarianten. 

@nlz weißt du noch was das Polrad wiegt? Das ist ja ein abgedrehtes, „Alt“

 

[Jimscoot]

11 hours ago, GiulioEX125E said:

 

Well... VRONE cases surely are nice, with a good intake even if not optimal (ooptimal = bfa intake style, carb pointing backward and reeds pointing forward). Vespower ignition, I dont know, 1.2kg flywheel sounds a little bit too light, considering the lightest largeframe clutches weight around 1kg (Crimaz) or 1.3kg (Sip or standard Piaggio) so its 1-1.3kg on the clutch vs 1.2kg on the flywheel... I dont like that.

 

Anyway, my MHR with stock timings, on LML cases with the intake opened up and a fullcircle crank, with a phbh28 on vforce4 reeds and various box and resonance exhausts, pulled around 21-23 hp and 20-23 nm. Did  you get better results with your setup? Did you dyno it already?

Yeah, fair call. I’ve never dynoed the scooter as here in Australia most of them are setup for powerful road bikes and they aren’t interested in scooters.

Don’t get me wrong, I have struggled with this setup for over a year 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 

120main

6.5G float

300 float valve 

av266

x7 needle 3rd clip

55pilot

55slide.

sorry I haven’t mentioned my gearing

Standard px200 gearbox with Malossi 23/64 straight cut primary

im also running the laser welded Worb5 flowed reed valve crank, wasn’t sure if this was a good choice and would have preferred a full circle but there was nothing available at the time.

 

I have a friend with a fully worked quattrini M232 and the 187 is very similar in power, he had his dynoed and it’s peak is around 30hp, 

this is nothing really special in today’s world but what I like is that it’s very reliable and I can run for hours on the freeway with no overheating issues with my cht temperature maxing out at 135degrees celcius. 

 

 

Bearbeitet 19. Oktober 2021 von Jimscoot
Add on

[Gast]

vor 3 Stunden hat Tyler Durden folgendes von sich gegeben:

das ist ja mehr oder weniger das was wir damals auch raus hatten, mit ähnlichem Setup und verschieden Auspuffvarianten. 

@nlz weißt du noch was das Polrad wiegt? Das ist ja ein abgedrehtes, „Alt“

 

 

keine ahnung, aber die landen ja immer so um und bei 2kg wenn es gut gemacht ist 

[GiulioEX125E]

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.