Changing flywheel size... 4 bolts or 8 with locators?
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Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Tue Nov 26, 2019 3:39 am quote
Speedy have been overheating for "years" whenever cruising the TEMP goes way up & stays there... when knobbin it around twisties theres no issues!
When cruising I'm restricted to about 84km/h, yet on the twisties i stop looking at the speedo at 118km/h, then twist a bit further!

So far the following have been changed or tested:
Carb; a bazillion jet changes, float (white & black tried), needle (200/250, springs/normal), intakes, filters, vortex...
Timing; vespatronic numerous settings, CDI changed... blah blah...
Exhaust is normally a Boomstick, but also tried some boring standard thing (yeah Ginchi, remember heading to QLD Mille with that standard thing).
Fuel pump or not etc.
Gaskets & seals all replaced & leakdown done.
Pretty much every bloody thing has been replaced in some attempt to fix the overheating issue....

BUT.... Last week i was hanging out with a Crazy Guru (Mr Raphello for those playing at home) & mentioned this issue....
Then...
Somehow I (realised &) mentioned that While going to the QLD Mille that I REMOVED the side panel & had a dramatic (possibly 50f from memory) reduction in temp ...
this got me/us thinking about how an agricultural "air-blast" sprayer works & that the CLEARANCE between end of fan blade & housing has a direct relation/effect on the air-speed/flow ...

heres what I found when i looked (well, stopped ignoring)


For those that like research
A bit on the motor
modify VBC 2-port - the DYNO RESULTS are (finally) in ... (Page 3)

For those who don't now Speedy
Ode to Speedy - what has Speedy been up to?

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More gap than a skinny chicks thighs

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My crack

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a UFO would fall out of the sky with this much space



Last edited by SubEtherBASS on Fri Dec 06, 2019 8:43 pm; edited 1 time in total
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Tue Nov 26, 2019 3:57 am quote
Resolutions or is that revolutions
I've got this plastic fan, so I'm going to ream out the centre to fit, then bolt it on & see how it goes.

Footnote (or was that "back"-notes?)...
I've had the plans for many many years, & brought it as it was lightweight, but never fitter it as "in-depth research" (back when an online search for "porn" returned a mind boggling 327 hits, in a mere 12 minutes) suggested that having a lightweight fan caused an imbalance on the crankshaft, as clutch was heavier, PLUS, inertia changed engine performance... so i never fitted it.
Does anyone out there know about either of these theories?

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Gotta make that hole bigger!



Last edited by SubEtherBASS on Tue Nov 26, 2019 3:59 am; edited 1 time in total
Ossessionato
05 Stella, '62 VBB, 76 Sprint V, 63 GL
Joined: 16 Jun 2011
Posts: 2268
Location: Chicago. Well, Evanston, but that's almost Chicago
Tue Nov 26, 2019 3:58 am quote
Hmmm...interesting question.

It'd be easy enough to test. Cut a cardboard ring and duct tape it over the opening, see if that makes it run cooler or hotter. You could test the converse by fitting a spacer between the flywheel cover & case and measuring temp that way, too.

Lastly, if you have a leaf blower or other high-volume fan, you could hit the motor with that while running on the stand and see if it affected temps, which would help confirm that part of your issue is that you need more airflow.

Have you considered painting the head and cylinder black? That will improve heat radiation and reduce temps by a few degrees (~10f?), too.
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Tue Nov 26, 2019 5:08 am quote
Nerdy shit & pretty pictures prevail
"Fan Tip Clearances" have a great effect on airflow (& in this instance, cooling)

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Nice nerdy wordy stuff

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Colourful pictures prevail

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The purdy pics say it all

Addicted
GL, PK, PE200, Rustbadge
Joined: 24 Apr 2012
Posts: 718
Location: Deep in the heart of Texas
Tue Nov 26, 2019 7:05 am quote
You might have something here. Do you recall this post from Poidog about the smallie fan? http://modernvespa.com/forum/topic152306?highlight=.
The smaller fin et3 flywheel cooled better then the larger one.
Molto Verboso
Joined: 26 Oct 2015
Posts: 1875

Tue Nov 26, 2019 8:47 am quote
I have a Vespatronic on my T5. I never tried using the plastic fan that came with the kit though. Iíve had one of those fancy MMW aluminum fans on from day one of my build, so I donít have anything to compare it to. They were touted to cool better, so thatís why I went with it.
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Tue Nov 26, 2019 1:23 pm quote
rowdyc wrote:
You might have something here. Do you recall this post from Poidog about the smallie fan? http://modernvespa.com/forum/topic152306?highlight=.
The smaller fin et3 flywheel cooled better then the larger one.
I found (using that "SEARCH" function I so often refer to, then everything on the ipad closed after an update & I couldn't find it again yesterday) & read that (extensively), which helped with clarifying my thoughts... it's really the best thread in NSM on the topic.

Also found this online, but it was difficult (& as exciting as a porn mag) without the/any pics...
From the figure, it can be clearly seen that rotor with
partial shroud (PS) shows increased total pressure coefficient, (o) compared to basic configuration for all the flow coefficients at the tip clearance (=2.2%). From the figure, it can be seen that the extent of region of improvement increases with reduction in flow coefficient. That means the higher the loading more is the benefit due to the partial shroud. For the tip clearance =5.1%, the benefits of PS are reduced. It can also be observed that, the total pressurecoefficient increases as the flow coefficient decreases for all the tip clearances. For tip clearance =7.9% configuration with partial shroud also shows higher total pressure coefficient compared to basic configuration. This may be attributed to the partial shrouds attached to the tip of the blades restricting the tip leakage flow and hence increased total pressure is obtained. Trend of the total pressure coefficient is almost same for both configurations at three values of tip clearances.
partial shroud also shows higher total pressure

coefficient compared to basic configuration. This may be attributed to the partial shrouds attached to the tip of the blades restricting the tip leakage flow and hence increased total pressure is obtained. Trend of the total pressure coefficient is almost same for both configurations at three values of tip clearances. Absolute Velocity, c: is the axial distribution of non-dimensional absolute velocity at the rotor exit for two configurations and three flow coefficients for three values of tip clearances. Velocity and its radial and tangential components are non-dimensionalized with the rotor tip speed. From the figure, it can be seen that the absolute velocity increases with flow coefficient for all the tip clearances. For the three values of tip clearances at two flow coefficients (=0.34 and 0.2 clearly indicates an increase in absolute velocity in the rotor shroud region for the configuration with partial shroud, compared to the basic configuration. This is due to increase in tangential velocity, which means increased energy transfer. At flow coefficient (=0.34) an increase in absolute velocity is seen in the rotor hub region for the configuration with partial shroud, compared to the basic configuration. Trend of the absolute velocity is almost same for both configurations at three values of tip clearances. A careful study of this figure shows that basic configuration give lower absolute velocity for all the flow coefficients and for the three values of tip clearances. This lower absolute velocity is due to leakage flow in the flow field, which mixes with the main flow at the exit, resulting in lower values of velocities. Radial Velocity, cr, is the distribution of non- dimensional radial velocity at the rotor exit for three flow coefficients and two rotor configurations for three values of tip clearances. For three values of tip clearances, it can seen that radial velocity increased at flow coefficients (=0.34 and 0.2 in the rotor shroud region for the configuration with partial shroud, compared to the basic configuration. It can be observed
IJSER © 2014 http://www.ijser.org
International Journal of Scientific & Engineering Research, Volume 5, Issue 1, January-2014
ISSN 2229-5518
from the figures that at the shroud region for three values of flow coefficients show decrease in radial velocity for hub region. At shroud region, boundary layer thickness increases due to partial shroud. Therefore higher loading on the blade causes decrease in radial velocity in the hub region. Tangential Velocity, cu is the axial distribution of non-dimensional tangential velocity for the three flow coefficients and for both configurations, and for three values of tip clearances at the rotor exit. From the figure, it can be clearly shown that configuration with partial shroud increases tangential velocity for two flow coefficients (=0.34 and 0.2 compared to the basic configuration of rotor. But at flow coefficient (=0.1, configuration with partial shroud shows increased tangential velocity for hub region. Also the trend of tangential velocity is almost same for both configurations at the three values of flow coefficients. Mass Averaged Performance of the Compressor:
Mass averaged performance of compressor (Fig. 5) shows the variation of mass averaged values of total pressure coefficient (ψO2) and static pressure coefficient ( ψS2 ) with flow coefficient. The mass averaged values are defined as follows:
partial shroud (PS) compared to basic configuration. The 1030 possible reason may be due to reduction in the detrimental effects of the tip clearance flows by the partial shroud. Partial shrouds have more beneficial effects at higher values
of tip clearance.
NOMENCLATURE
b Distance between the shroud and hub at the rotor
exit (m)
Cd Velocity in delivery duct (m/s) Cs Velocity in suction duct (m/s)
d Rotor diameter (m)
N Rotational speed of rotor (rpm) Nc Coupling power (Watt)
Nsh Shape number = NV/W3/4
PS Static pressure (Pa) PO Total pressure (Pa)
pd Delivery pressure (Pa)
ps Suction pressure (Pa)
t Clearance of the rotor blade (m)
U2 Rotor tip speed = (d2N/60) (m/s) V Volume flow rate (m3/s)
W Specific work (m2/s2)
 Flow coefficient (defined in the text)
 Efficiency (defined in the text) 
The mass averaged values of total pressure coefficient and static pressure coefficient at the rotor exit for both configurations at the three values of tip clearances clearly show that partial shrouds are beneficial in improving the
pressure rise of the compressor, compared to the basic
o Total pressure coefficient= 2Po / U2
 2
s Static pressure coefficient= 2Ps / U2
 Density of air (kg/m3) 
 Relative tip clearance = (t/b2) 
IJSER
configuration. It can also be observed that the mass
averaged values of total pressure coefficient and static pressure coefficient at the rotor exit for both configurations at the three values of tip clearances, increasing as the flow coefficient decreases. Also mass averaged values decrease with increase in tip clearance. From the figure, partial shrouds are found to have more beneficial effects at higher values of tip clearance. CONCLUSIONS:
The following major conclusions are drawn from the
present investigation.
1. Configurations with partial shroud (PS) shows higher energy coefficient and efficiency compared to the basic configuration at all the values of tip clearance.
2. Basic configuration at =7.9% gives poor performance i.e. reduced operating range, reduced energy coefficient and efficiency over the entire operating range. Partial shrouds have beneficial effects in increasing energy coefficient and efficiency of compressor.
3. Radial velocity at the exit of rotor almost remains
constant from hub to shroud for all the configurations and flow coefficients.
4. The tangential velocity at rotor exit decreases with increase in flow coefficient and this difference is reduced with decreasing flow coefficient.
5. The mass averaged total pressure coefficient and static pressure coefficients are higher for configuration with Sitaram, N. and Pandey, B. (1990) ďTip Clearance Effects on a Centrifugal CompressorĒ


Then there was this gem to help clarify (or is it confuse?) the idea...
https://www.researchgate.net/publication/318827927_The_Effect_of_Fan_Tip_Configuration_on_Air-Cooled_Condenser_Axial_Flow_Fan_Performance

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Can't wait for B2



Last edited by SubEtherBASS on Tue Nov 26, 2019 1:41 pm; edited 1 time in total
Ossessionato
73 Rally, 74 Rally, 76 ET3, 80 P200, 63 Li125, 65 Li225 Silver Special, 86 Elite 80, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3306
Location: Oceanside/ SF
Tue Nov 26, 2019 1:40 pm quote
Makes sense a gap would affect things. Got the original flywheel still? Throw that on and compare the gaps or experiment like Chandler suggested.

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checking the gap



Last edited by MJRally on Tue Nov 26, 2019 1:41 pm; edited 1 time in total
Hooked
PX 150
Joined: 15 Sep 2006
Posts: 482
Location: Gold Coast, Australia
Tue Nov 26, 2019 1:41 pm quote
Malossi vespower.
Rarely get over 135c fast long freeway
https://www.malossistore.eu/en/cooling-fan-vespower-187-7417246B-P
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Tue Nov 26, 2019 1:52 pm quote
MJRally wrote:
Got the original flywheel still? Throw that on and compare the gaps or experiment like Chandler suggested.
the plastic one ive had for years is same size as original VBC, that's why ill try that one. Don't think I could get an original VBC metal one to fit easier , as the "rivets" are beefy & pressed, plus the plastic option is easier to modify the centre hub
Hooked
2001 LML 150
Joined: 16 Jul 2017
Posts: 331
Location: Melb, Aus
Tue Nov 26, 2019 1:53 pm quote
Callum.. you're absolutely 100% correct about the blade gap and the losses, and the articles will always back that up.

The million dollar question is how do you reduce those gaps and the losses? What's the practical solution?

Jet engine designers go to incredible lengths to reduce the losses around blades and tips. They use everything from abraidable liners where the blades cut their own channels to shrinking/expanding the cases using cool or hot air to keep gaps to a minimum.

I'd look into reworking the fan shroud for a start. That's the obvious one to me. Some sort of abraidable material like a dense foam could be a possibility, or even build up the inside with layers of balsa wood or something?

The big concern would be having any material dislodge and block the air flow path. You couldn't do (risk) this work without having a temp sensor onboard.

It's an interesting subject though...
Ossessionato
1976 Super (x 2), 1974 Primavera (x 2), 2006 Fly 150
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Posts: 4916
Location: So Cal
Tue Nov 26, 2019 2:32 pm quote
Yep yep... more engineering went into the fan and shroud than meets the eye... even a small gap will allow precious cooling air to leak out. I know from experience.
Ossessionato
73 Rally, 74 Rally, 76 ET3, 80 P200, 63 Li125, 65 Li225 Silver Special, 86 Elite 80, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3306
Location: Oceanside/ SF
Tue Nov 26, 2019 2:38 pm quote
SubEtherBASS wrote:
MJRally wrote:
Got the original flywheel still? Throw that on and compare the gaps or experiment like Chandler suggested.
the plastic one ive had for years is same size as original VBC, that's why ill try that one. Don't think I could get an original VBC metal one to fit easier , as the "rivets" are beefy & pressed, plus the plastic option is easier to modify the centre hub
Wasnít meaning to say change the fan, just slip a flywheel on the crank and measure.

I agree with Philos about adjusting the shroud. Got a spare fan cover you can hammer/bend the cover some?
Molto Verboso
1979 P150X, 1983 P200E, 1987 T5, 1996 PX200E, 2011 Yamaha Fazer 600 S2
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Posts: 1654
Location: Veria, Greece
Tue Nov 26, 2019 3:39 pm quote
I think this was discussed before on another thread...

FYI, curved fins produce more air but don't rev as much as the straight ones...

Here's mine....

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IMG_0369.JPG

Ossessionato
2015 GTS300, 1974 Primavera, 04 Ninja 250
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Tue Nov 26, 2019 4:15 pm quote
Why does Speedyís cover have so few louvers?
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Tue Nov 26, 2019 4:23 pm quote
sdjohn wrote:
Why does Speedyís cover have so few louvers?
It's a pre-P series cover.
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7129
Location: Victoria, Australia
Tue Nov 26, 2019 6:11 pm quote
As well as trying different fans, you could try some pliable card with weights glued to it. Once the motor is running, place the card over the fan inlet and see how much weight can be added before it'll fall off. This will give you a reasonable comparison of the ability of the fan to draw air through.


Also - you did try a 'standard' type (in Callum-speak it translates as "boring") but that was on the LML iirc. Still think you need to try an exhaust (any exhaust) with a larger stinger. This is to check whether you are building up heat that is not able to escape.

For anyone reading this... the scooter overheats when on a longish straight/up longish hills, otherwise runs fine.
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Tue Nov 26, 2019 11:16 pm quote
Exhausting
Replacement exhaust is ready to go on...

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The facade of Dans Exhaust...

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Purdy welding

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Dans house must have had too much insulation!

Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7129
Location: Victoria, Australia
Wed Nov 27, 2019 12:43 am quote
Re: Exhausting
SubEtherBASS wrote:
Replacement exhaust is ready to go on...
What is the diameter of the outlet compared to the Boomstick?
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Wed Nov 27, 2019 2:30 am quote
Re: Exhausting
Ginch wrote:
SubEtherBASS wrote:
Replacement exhaust is ready to go on...
What is the diameter of the outlet compared to the Boomstick?
I.D.
Boomstick: 23mm
Dans: 26-27mm (its already bent)

YAY
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7129
Location: Victoria, Australia
Wed Nov 27, 2019 5:40 pm quote
Re: Exhausting
SubEtherBASS wrote:
Ginch wrote:
SubEtherBASS wrote:
Replacement exhaust is ready to go on...
What is the diameter of the outlet compared to the Boomstick?
I.D.
Boomstick: 23mm
Dans: 26-27mm (its already bent)

YAY
I imagine that's enough to test the theory.
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Fri Dec 06, 2019 4:49 am quote
Trying to make a circle from the outside.
Well, I've been trying to work out how much to ream out the inner of the VBC sized plastic fan to fit the Vespatronic hub. The "trickiest" bit is making a slightly larger circle, but from the outside!
Happily the size needed is the same as a Marmite jar, even better, its NOT the size of a jar of Vegemite (Kiwis & Aussies will understand that reference).
Then it was onto ensuring the mounting holes are in the exact right place.
Ohh this would be so simple if i knew where the centre was

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the "slight diameter variation" can be seen.

Technical tools: Marmite Jar & antique calipers

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Roundabout round?
The centre punch holes are even (i hope)

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Gotta grind it out to the smaller line, the others are for reference once it gets close

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Still not sure what to do about the 4 "locators".
Will only 4 bolts be enough?
Or does it need all 8?

Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Fri Dec 06, 2019 8:51 pm quote
It fits
Please Have a look at the LAST photo above... do you think the 4 bolt holes will be enough or should I try to work something out so the extra 4 locator holes can also be used.

It changes where i drill the 4 (or 8.) holes.
Ie if 4 then 45deg offset to original 4 holes already in fan.
If 8 then 22deg offset to each side of original holes.

If you think it needs all 8 holes, then what would you suggest for the locators?
As can't fit a bolt/nut in them, as inside/engine-side is partially covered by magnet.

Also, I'm thinking about using a loctite (or epoxy?) product to "glue" to flat surfaces, which i could add extra & "pour" some in the locating holes to fill them up & it would mean they're kinda connected to the rest of the glue... or is that a bad idea, just in case the heat of the engine or centrifugal forces dislodge it & the glue goes flying around under the commutator?

The VBC fan has metal washer inserts moulded into it, likely for extra strength & a greater surface area & so plastic wont fracture, distort or compress... should i just drill the new holes bolt size or what could i do for extra strength? I'm thinking a thin washer under the bolt will do the trick, as new fan is thinner than original Vespatronic fan
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Fri Dec 06, 2019 8:58 pm quote
Holes everywhere!
Here are some more pics of holes...

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Location if only using 4 bolts

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Location if using 4 bolts & ????? as 4 locators

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Just A hole

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Snug fit

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Differing thickness

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Locators or not

Addicted
bare metal cafe racer
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Location: Aotearoa (New Zealand)
Fri Dec 06, 2019 9:06 pm quote
Itís all gonna be opinion 4 vs 8 - canít imagine anyone can provide actual evidence that applies to your setup.

My 2c opinion is 4 is fine. More holes = more weakness (holes) If 4 isnít going to hold it then neither will 8. 4 sounds a lot easier. I wouldnít even bother with epoxy - proper threaded attachment (bolts) should hold. Loctite on the bolts maybe.
Hooked
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Sat Dec 07, 2019 6:41 am quote
Rock stock vs Cooling Mods
SubEtherBASS, following your post in anticipation to see the end results!
Nice write up and nice job making the fan fit!

All your info seems to be pointing to a result of: 1) cooler running engine, 2) less fan tip drag/vortices, 3) both which will give you more reliability and more power.

My 2 cents on the holes is go with 4 holes. Same reason as Pheasant Plucker said. More holes = less material and less strength. Make the smallest sized holes possible to just fit the bolt, and good sized washers to distribute the pressure on the fan.

Wishing you great results.
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bare metal cafe racer
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Location: Aotearoa (New Zealand)
Sat Dec 07, 2019 3:48 pm quote
Hereís a thought...

Why not modify the shroud you have? Cut a piece of aluminum sheet to close the space - rivet/bolt it to the shroud. Could look awesome.
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bare metal cafe racer
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Sat Dec 07, 2019 3:52 pm quote
And realise a light flywheel will mean you need to increase the idle revs (momentum to keep ticking)... possibly a lot with a plastic fantastic.
Hooked
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Mon Dec 09, 2019 5:36 am quote
when i did the same as you are attempting, albeit with a standard flywheel with knackered fins, i used 4

20170913_211226.jpg

Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7129
Location: Victoria, Australia
Mon Dec 09, 2019 1:04 pm quote
I would have thought that 4 was fine, especially as the plastic fan without much mass shouldn't move around much.

Question is, how much does the flywheel and plastic fan now weigh? If it's too light then it's hard on the clutch apparently. I was also thinking about a spacer (/weight) that would push the fan out closer to the cover - something a few people have mentioned is closing up that gap to see if it makes a difference. Easier to do with a strip of that stick-on foam to the cover, but if you needed to add weight then...
Hooked
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Wed Dec 11, 2019 6:17 am quote
Ginch wrote:
Question is, how much does the flywheel and plastic fan now weigh?
Mine weighed in at 1.9kg using the old school non electric start flywheel and 1.6kg when i repeated on an electric start flywheel
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7129
Location: Victoria, Australia
Wed Dec 11, 2019 1:24 pm quote
SIP says the Vespatronic weight is between 1400 and 1800 grams, so I would think SEB's one wil end up at less than 1400.
Hooked
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Location: 3rd Rock From the Sun
Thu Dec 12, 2019 3:21 am quote
Ginch wrote:
SIP says the Vespatronic weight is between 1400 and 1800 grams, so I would think SEB's one wil end up at less than 1400.
That wouldn't be much of a problem if the clutch is banded or a stronger aftermarket part. When i ran the HP4 flywheel which weighed in a 1000g+/-, i used to go through standard clutch baskets at a fair rate of knots on my 210, the acceleration was very aggressive and a pig to keep the front wheel down Once i changed to a banded clutch only issue i had was premature wear on the 5 plate conversion.

Having said that Jr. has shredded banded clutch baskets , but he does have a tendency to ride like the hounds of hell are on his tail. No mechanical sympathy whatsoever
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Thu Dec 12, 2019 4:27 am quote
Decision:
4 bolts, with reasonable sized O.D. thin washers.
IF there is more than 1mm or so gap between flywheel & cover, then ill add double-sided mounting tape to pack it out & add 'gripping power'.

I'll weigh things up and let ye all know, plus compare vs original VBC flywheel (where ohh where are those coke scales?).

Clutch Basket is DRT Race, with high tensile (10+) rivets/locators to hold it all together, as screwed drive gear off it the original ones.
Clutch plates, well, they need replacing, but they are a "Sacrificial Component" (track 3 off Mechanical Sympathy's first album), to ensure there is a cheap weak-point in engine (ie so gears don't snap)

"Mechanical Sympathy"... is that a punk band of skateboarding nutcases?
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 7129
Location: Victoria, Australia
Thu Dec 12, 2019 1:39 pm quote
I seem to recall your clutch plates are worn just beyond their use by date...
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Fri Dec 13, 2019 2:16 am quote
Ginch wrote:
I seem to recall your clutch plates are worn just beyond their use by date...
That is very true, however, if the still ok for burnouts, then they're ok.
. I have the new ones soaking happily though

Last edited by SubEtherBASS on Fri Dec 13, 2019 2:33 am; edited 1 time in total
Ossessionato
2 matching N.Z. '69 VBC Super, 177cc Racer, VespaCross Bodge, Puch SRA150, Piaggio Zip 100! & others
Joined: 26 May 2013
Posts: 3849
Location: Millbin, Ostrayleea, mate
Fri Dec 13, 2019 2:28 am quote
Weight n See
He weights are in...

HUB w screws... a mighty 1335gm
Hmmm, i spy an anglegrindin' session!

Vespatronic plastic fan = 125gm (1470gm with hub)
VBC style plastic fan = 145gm, with washers (1490gm with hub)
Original VBC Hub & Fan setup = unknown, i dunno where it is, sorry
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