Cylinder vs crankcase (reed) induction
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Thu Nov 09, 2017 6:37 am quote
Following Ginch's thread on the new Malossi 177 kit, I've been thinking about an engine that I'd like to build over the cold winter months. I have a fairly ratty but serviceable 200 engine casing (PX EFL) which has already been molested for reed induction by the previous owner, so a rotary build is totally out of scope. I'm now considering the components that I would need to build a 25+hp motor. My build objective would be dependable street racer, as I already have a great touring setup.

The cost of crankcase reed induction is considerable when you add the cost of the reeds (RD350) + block (MRP/MMW/MBD) to the cost of the cylinder kit. The more expensive Pinasco 960 VTR Slave (cylinder induction) kit looks better value because it includes the reed setup.

Questions:
- Can anyone vouch for the Pinasco VTR kits with direct/cylinder reed induction?
- Is cylinder induction a better (and sensible) option, given the objectives?
- Is Malossi still king for 200 based power builds, and would the Sport or MHR be the better choice? I'm assuming MHR, but never used Malossi before.
- If I went cylinder induction, would I just blank off & seal the crankcase inlet, or is it better to fill it in completely? Does it matter?
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Thu Nov 09, 2017 8:54 pm quote
Like where you are going with this. Not going to be cheap though.

I can't get over excited about the VTR slave. I think it would make decent power but the whole thing would be a compromise and not as powerful as an MHR project.

Fastest street racer at the moment would be something like a 221 MHR, 60mm bell crank, 39mm carb, V4 Reeds, 22/68 primary and some big fat expansion pipe. Quite an expensive shopping list, I assume you have no interest in adding water cooling to that?

Have you got the casings split? Any issues that need fixing first, helicoils etc. ?
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Thu Nov 09, 2017 9:09 pm quote
Whatever you decide, please make a build thread on it, this sounds very interesting....
Veni, Vidi, Posti
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Thu Nov 09, 2017 9:48 pm quote
The Pinascos for whatever reason always seem to have very low port timing. Without seeing power figures you would have to think Malossi is the better bet. Although I do like the reed on cylinder.

There is another option that looks great. As long as your pockets are pretty deep of course. The Quattrini M232/244 are cast with this in mind obviously. This work was done by Patrick at P-Town scooters according to this -
https://www.facebook.com/groups/VintageScooterBuildersShowcase/permalink/1746613352030145/

Quattrini 1.jpg

Quattrini 2.jpg

Quattrini 5.jpg

Quattrini 3.jpg

Quattrini 4.jpg

Quattrini 6.jpg

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Thu Nov 09, 2017 10:43 pm quote
Ha ha, pockets not really deep enough for Malossi or Pinasco, let alone Quattrini M244 or H2O cooling, but over spending on Vespa bits and bobs is the only way for me to get through the long winter months!!

Once the cases are clean and fully inspected for cracks etc., i'll know how to proceed. I may need one helicoil where the old reed block was mounted, hence the option to go with cylinder induction (Pinasco VTR). Will do some research on port timings vs the MHR.
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Thu Nov 09, 2017 11:39 pm quote
Just something to think about with the Pinasco. I wonder how much more street racer the port timing is with a 60mm crank in the 57mm cylinder?

If anyone has the measurements of both cylinders down from deck, It might be the way to go to get the Pinasco more interesting.
Veni, Vidi, Posti
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Fri Nov 10, 2017 4:11 am quote
Jack221 wrote:
Just something to think about with the Pinasco. I wonder how much more street racer the port timing is with a 60mm crank in the 57mm cylinder?

If anyone has the measurements of both cylinders down from deck, It might be the way to go to get the Pinasco more interesting.
Some info from the GSF -
DRC_174 wrote:
So, have one lying here should be the 60mm variant.

From the first impression very enthusiastic but I have not too much dealt with it. A fast timing measurement via portmap results in the 170/122 (+/-) m What I think has great potential. The piston, that's it! Almost no buttock, but the in-house tests were confirmed to me as successful. I do not have a 60mm wave right now, otherwise a full measurement (times, compression, QC) would follow. Sequel follows.
No 'sequel' as yet, however the same guy did one of the traditional (case intake) cylinders and said this -
DRC_174 wrote:
Have finally get a 9TX in the fingers. Is mounted but not yet in the frame. 60s stroke, with central candle. Values ​​original here were 177 / 129.5. 

Now it is 189.5 / 129.5 at 61% outlet width after a slightly agitated dysentery. Housing has been adjusted, you can do most without Aufschweissen, the latter would probably lay down a better design. I'm looking forward to the next few hours, but now I need some sleep, then there are updates. 



Setup: 
membrane, 30mm PHBH 
60mm shaft. 
189/129 on SIP Performance 2.0. 
Pinasco Flytech
The whole on a long translation. 
Not the same cylinder but perhaps an indication of where the VTR might get to? An interesting comment about the height of the piston was that it would make it easy to run a 62mm stroke. Here it is shown alongside a Malossi piston.

Kolben_8.thumb.JPG.9b538f235032e75b7eaf0d1dab4ddbc8.JPG

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Fri Nov 10, 2017 7:07 pm quote
They are some quite strong figures from the Germans. That's got to do near 10,000 rpm in gear. Any follow up on how it went?

I found some more posts on the GSF and they seem to think the previous Pinasco cylinder 60mm version gives the following.

Auslass :177 Grad

Überströmer: 126 Grad

Vorauslass: um 25

If the new Slave is similar to this, then a slight brush with the Dremel here and there and it would be quite a street racer. Chances are the new Slave one is further improved already but they always leave something that can be tweaked.

I have always cut several mm off the bottom of the old Malossi pistons. They were just too long. New MHR ones are shorter.

Now, a 62mm crank in a Slave cylinder. There's an idea....
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Sat Nov 11, 2017 12:17 am quote
Cheers chaps. Port timings to one side for a moment. If rotary is not possible (definitely the case for me), what technical and power advantages/disadvantages are there between crankcase and cylinder reed induction? Is there a clear winner, or does it depend on the build objectives?
Veni, Vidi, Posti
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Sat Nov 11, 2017 3:55 am quote
I found this on a dirt bike forum. Not something I had given much thought to but makes sense.
Quote:
From what I understand case reeds allow the fuel/air mixture to have a straighter path when entering the combustion chamber. Without case reeds the mix must go through the carb, then down to the crank, then turn 180 deg and go up to the top. With case reeds, the mix goes through the carb to the crank, then turns 90 deg up to the top. You basically get better throttle response.
I guess though that they are not dealing with a Vespa case where the crank blocks the path for a fair percentage of the time.
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Sun Nov 12, 2017 5:41 pm quote
money money money
Kingwelle are doing a 64mm crank for quattrini. I have no experience above 60mm but I'm assuming your going to get a few HP more with that monster. For example Quatrinnii 244cc goes up in displacement to 255cc.

I assume they to a malossi 64mm also. When I next feel like spanking a couple of thousand dollars I will do a 64mm malossi.
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Sun Nov 12, 2017 6:15 pm quote
They probably do. The only difference that Q. crank has from other ones is the 125mm (or maybe 126?) rod.
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Wed Nov 21, 2018 3:00 am quote
Over a year late, but I've just committed this one to the build by ordering a 60mm bell crank, and I have now assembled the gearbox components. I'll be using a PX125 setup with a 21T clutch and a 3.00 x 11 wide SIP rim at the rear, most likely with a 130/70 x 11 tyre.

I'm on the lookout for a Malossi MHR kit at a good price, so the displacement will end up at 221, but first of all the case halves need to be vapour blasted, checked over and somehow strengthened around the primary shaft and the flywheel side bearing. Perhaps the CMD CNC back plate is a good way to address the input shaft. I'll then use a Malossi base packer as a template to get the case ports looking good, prior to buying the top end kit.

Does anyone have a recommendation for base packer thickness? This will be a street racer motor and will be used in a freshly painted 1987 PX200E (Piaggio red). The idea is for the scoot to look absolutely factory, but with a very peaky motor under the hood. The only giveaways will be a front disc and the fat rear tyre. I'm even thinking a modified box exhaust to keep it looking close to original.
Veni, Vidi, Posti
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Wed Nov 21, 2018 3:14 am quote
Have a look at this, second page. Nice solution!
P221 from Rotary to Reed

Packer thickness depends of course on where you want your squish. I've had a few 60mm cranks and they all seem to end up with about a 1 - 1.1mm packer, never got as far as 1.5 which you would think would be correct.

So, 11 inch wheels? I didn't know they existed!
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Wed Nov 21, 2018 3:38 am quote
I'll definitely check out that thread Ginch. The rims are quoted as 11" by SIP, but the main attraction is the width. They need the mods to the swing arm and they need a packer on the hub.

https://www.sip-scootershop.com/en/products/rim+tubeless+wide+tyre+sip+_83045000

I've not thought about the head and squish at this point. Just looking to get the cylinder raised sufficiently so that the ports are in the best position. I gather the MHR will have no problems with 9000 RPM, assuming other stuff is done properly.
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Wed Nov 21, 2018 3:43 am quote
swa45 wrote:
I'll definitely check out that thread Ginch. The rims are quoted as 11" by SIP, but the main attraction is the width. They need the mods to the swing arm and they need a packer on the hub.

https://www.sip-scootershop.com/en/products/rim+tubeless+wide+tyre+sip+_83045000
On the description it says that no spacer is needed...

3.00-11: The premier league of wider section tyre conversions ! Our 3.00/11“ size wider section tyre wheel is delivered including two aluminum sleeves for the engine pivot. No further spacer is necessary. To compensate for the wheel being off the centreline of the scooter the pivot on the swing arm of the motor needs to be shortened by 1cm on the right hand side. The motor is so moved to the right. 110/70-11, 120/70-11“ or 130/70-11“ tyres can be used with this conversion kit. Because of its wider rim width we recommend the use of a 2.50-10“ SIP tubeless rim at the front.
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Wed Nov 21, 2018 4:08 am quote
Even better that no spacer is required between hub and rim. Cheers, I missed that bit.

SaFiS, how is your motor since the rebuild? Will you be using the CMD backplate on this motor, or do you think the welded plate in the gearbox is enough to strengthen the input shaft area of the case?
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Wed Nov 21, 2018 10:57 am quote
swa45 wrote:
SaFiS, how is your motor since the rebuild? Will you be using the CMD backplate on this motor, or do you think the welded plate in the gearbox is enough to strengthen the input shaft area of the case?
To tell you the truth, life and work (new employer) got in the way and I have put it aside for a while. It's running great but I still need to fine-tune the carb. It's a bit rich at low rpm and behaves like it's flooding, especially when I'm in traffic. I have the two-stage Boyesen reed petals and all the plumbing for a fuel pump at hand, but not the time. I'm also planning a respray, the PLC Corse wheel hub and some other stuff (install SIP speedo, change to AC/DC and install a battery, an Arduino EGT I had built way back, etc.). I just hope I'll find the time. About the CMD backplate, yes it's going on this motor. Better safe than sorry and I also love new shinny things...
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Wed Nov 21, 2018 3:50 pm quote
swa45 wrote:
Just looking to get the cylinder raised sufficiently so that the ports are in the best position.
Just been reading that the 221 MHR cylinder is longer, with port positions to suit. I hadn't realised that, so no need for packers with a 60mm crank. Hopefully the supplied base gasket is all I will need.
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Wed Nov 21, 2018 4:07 pm quote
swa45 wrote:
Just been reading that the 221 MHR cylinder is longer, with port positions to suit. I hadn't realised that, so no need for packers with a 60mm crank. Hopefully the supplied base gasket is all I will need.
Personally, I would go for the "normal" MHR and play with packers. The longstroke version limits you to a longstroke crank and you can't play with port timings...
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Wed Nov 21, 2018 11:50 pm quote
Agree. The 60mm cylinder is too restrictive. You won't like it.
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Thu Nov 22, 2018 2:08 am quote
I assume that with an MHR you would not consider putting any packers on the head? In which case there is nothing to be lost with the 57 version, and potentially a bit to be gained?
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Thu Nov 22, 2018 3:02 am quote
Cheers chaps.

Does anyone have a table that shows the TD for a 57mm MHR cylinder, with a 60mm crank, with different base packers?

I understand about TD trade offs, but I want to avoid it being painful in the lower rev range and climbing hills. I'm not into wheelies and doughnuts, but strong acceleration is appealing. I have a torquey PX225 for touring and pillion work.

I was thinking that a 0.8mm base packer would be a good start, but where would that put the TD? I would most likely use the supplied head, unless good squish is not achievable. As stated earlier, I'm going to use a 68T primary, probably with 21T clutch to compensate for the 130/70 - 11 rear tyre. Otherwise it's a PX125 box. Assuming it can achieve 8000 RPM in 4th, 78MPH is good enough for me.

The exhaust I have in mind is a big box style, maybe the Pipe Design S-Box, to keep the [almost] standard look to the scoot. PD quotes 'up to 128TD/188ED' with an MHR for this pipe. Otherwise you're into proper expansions.

Given the above, is the MHR the right choice?
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Thu Nov 22, 2018 8:29 pm quote
I don't think there is any quicker than the MHR. The Germans say the big box is no slower than an expansion. I can't quite believe it but even if its close it will do.

The MHR 57 primary transfers are an average of 45.3mm down from deck. And secondaries average 45.6mm. A 0.8mm base on my cylinder would be 186/129/28.5.

You'll need variable timing but not going to have any issues going up hills. With so much power this is all a thing of the past.

Did you decide rotary or reed? And what size carb you have in mind? If just a 30mm, then rotary is quicker and cheaper.
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Fri Nov 23, 2018 12:20 am quote
The rotary pad is long gone on this set of cases. The previous owner saw to that. I've not thought too much about the carb, but I'd like to buy the manifold base, really just for the template at this stage. Current thinking is a 34mm VHSB or TMX 35, but not as big as 38/39. To stick with the 'sleeper' theme, it needs to fit under the side panel without modification.

186/129/28.5 sounds fun, without being OTT. I'll probably buy the kit without a head. With only 0.8mm packing at the base, I'm going to need some extra clearance up top, and the MRP 'touring' head, with ~0.7mm shaved off it will get me to ~1.2mm SBC in theory.

Out of interest, where would the port timings be with just the supplied base gasket and the full 1.5mm in/under the head? Sufficiently different to make the Sport a better option than the MHR?
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Fri Nov 23, 2018 1:52 am quote
If going for speed the sport is not the best kit for the job. Before getting the MHR I was wondering if it would be too peaky and unstable but seems to cruise fine, surprisingly good economy and if you need to go anywhere, just buzzes along in the pack. I think the new scavenge pattern really works.

Just a single 0.1mm base gasket on my cylinder would be near to 183/125/29. Compared to what I'm used to this would be......um......slow.

As reed is no choice, then the 35mm carb is a must.
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Sat Nov 24, 2018 4:40 am quote
Jack, so you're in favour of the 0.8mm base packer with 57mm MHR cylinder and 60mm crank? I guess I'm really after a 1.0mm packer and use it without the supplied base gasket underneath, or is it better to go 0.8mm packer + base gasket, to get the 'crush' effect of the gasket and therefore a better seal?

Would a 1.5mm base packer make it a bit too peaky in your opinion?
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Sat Nov 24, 2018 9:34 pm quote
0.8mm is a good place to start. The fewest is preferred to avoid shrinkage but it all works. These kits like any other kits are more like hand made than mass produced. Pretty much the same but not exactly. Depending on what you are after there is actually a lot of scope to move in the 1.5mm but there is too much. As they are close to the limit they lack overrun but not really an issue.
I am just about to change my packer for the third time and hopefully the last but with a new crank and flywheel there are a few unknowns to deal with.
You'll need to run yours and see how it performs. Its easier to adjust the barrel to the gearing than messing about with cogs.
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Tue Dec 04, 2018 2:41 am quote
My reed block base arrived, so it's time to use it as a template and get the inlet opened up. The previous owner of the cases had already taken out the rotary pad, but the shape and size of the inlet is a long way from the Scooter & Service block that I bought. It extends a little further to the back of the case, but it looks like I need to remove a lot of material at the front (cylinder end) to match the S&S cutout. This will take out the threaded hole used for the carb box, but I guess I'll never need that again!!

Before I get the Dremel out, are there are gotchas? Can the inlet ever be too big? The S&S outer edge gets really close to the case mating surface, so I may retain an extra couple of mm to be on the safe side.

20181204_102511.jpg
Blue marks the S&S cutout. Getting a bit close to the case mating surface!

20181204_102344.jpg

20181204_102255.jpg

Veni, Vidi, Posti
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Tue Dec 04, 2018 5:40 pm quote
I do like that the S&S block is angled slightly so that the reed opening points more towards the gap between the crank webs (that's what I imagine it's like that for anyway).
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Tue Dec 04, 2018 11:53 pm quote
Like the reed block too. There is no too big for this hole. The bigger it is the more high rpm power there will be. With this in mind, where the previous owner has opened up further than the reed block on the clutch side. Brace yourself and cut the shiny new reed block out to this point to blend it all in together. While your at it, I would radius the entry edge in the reed block to remove that sharp edge.
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