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210061741
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THE STORY
With the cold weather movin it's way in I think it's time to embark on a new journey.
After being unemployed for the last 6 months and completing another engineering degree i landed a prestigous job yesterday.
Lead CNC Programmer / Shop Supervisor of a very nicly equipped Machine Shop. They have about 50 high tech CNC machines. Being a smaller job shop i anticapate the availibility of machine time.
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THE BASELINE
Earlier this year i purchased a Puch Moped Cylinder Kit and High Comp Head from Treatland.Cylinder Kit I have: http://www.treatland.tv/puch-70cc-reed-valve-kit-especiale-p/puch-reed-kit-especiale.htm
High Compression Head I have: http://www.treatland.tv/puch-moped-70cc-hi-compression-head-p/puch-hi-comp-head-70cc-maxi.htm
Reed Block I have: http://www.treatland.tv/malossi-phbg-reed-intake-block-p/malossi-phbg-reed-intake.htm
I am also running a PHBG 18mm Dellorto Carb on my current build and will be keeping the carb.
So all that makes a super sweet top end.
Nothing chineese left in the top end. all PUCH.
Cost: Around $200 not including the carb which is about $100 by itself.
Just so you all are aware of what it would cost you if you wanted to do this.
So we allready hit $300 and we dont have the bottom end.
4 sure this isn't the cheap way to go.
But them mopeds are still around after decades for a reason.
The quality is great for the price.
Sure I could machine a custom cylinder, but by the time you do that and get the cylinder plated or sleeved you would double that cost.
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THE BENIFITS
Benifits:
High Quality Piston, Cylinder, Wristpin, and Head
The cylinder is allready set up for a reed valve that accepts the Dellorto
Much higher horsepower will be generated
Faster speeds attainable
More Power to climb hills
Less Peddeling higher torque
Rideability in traffic
And best of all Reliability.
Therefor Benifits divided by cost = 4 me it is wort it.
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THE PROBLEMS TO OVERCOME
Were still left with the chineese bottom end.
The bolt pattern of the Puch Top End is Slightly different than the chineese.
You could fit it and make it work but that wouldn't make much sense.
After modifying a HT heavily you quickly find out that the bearings just don't cut it. None of them even if upgraded to higher quality they still fail rather quickly.
The crankshaft is the next problem.....
It's a bit heavy for the engine size and application.
The cranks arent machined true or balanced correctly.
So you allways have that disasterous vibration.
The metal the cases are made from is ****.
Thin Brittle white metal.
I don't understand how they get away with calling it aluminum.
It's more like ALUMIDUMB.
Pcs break off and the threads strip out so easily it's rediculous.
The mounting points could be much much better.
2 bolts in crappy pot metal on each mount just dont do it.
The Crankshaft seals leak and wear fast.
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THE CONCLUSION
Mchine Custom Cases:
Use quality aircraft grade aluminum.
Make the cases thicker.
Re-engineer the mounts:
Make the mounts alot thicker so there is 2 to 3 times more contact with the bicycle frame. This will stop the tipping of the engine to the side and provide a very solid mount cutting down vibration. It will also make the locating of the Engine and the rear drive sprocket consistent without misalignment of the cain.
Utilize 4 to 6 bolts in each mount.
Produce mounting kits instead of 1 size fits all.
The mounting kits will be changeable. In other words the mounting blocks with the radius cut it it will bolt to the engine rather than being a part of the engine.
For example have kits for different diameter frame tubes.
Make the front mount angle adjustable.
That way you can fit the engine perfectly.
Add an additional mount from the top of the cylinder head to the top tube of the bike frame.
Another great benifit of this type of mounting system.
A rear mount could be designed to bolt directly to the engine that can accept the Jackshaft from SBP.
You would need the Crank Freewheel system from SBP.
This would allow you to use there kit without the extra plates to mount the jackshaft. And since we fixed the alignment issues with the mounts drivetrain alignment would be seamless.
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SUMMARY
Essentially this plan will eliminate the majority of the Chineese parts leaving only the chineese clutch system and the chineese ignition system. I haven't had many problems with the chineese clutch. I have never worn out the friction pads. Once i adjust the main clutch spring the slipping problem goes away. It is compact keeping the width of the engine down and cheap.I am very interested in an upgraded clutch system to incorporate here.
IF ANYONE HAS IDEAS FOR A COST EFFICCENT BETTER CLUTCH PLEASE LET ME KNOW.
But all in all the clutch is the last thing i'm worried about.
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WHAT ABOUT THE ELECTRICAL SYSTEM
We all know the HT electrical system leaves much to be desired.
Like a stronger spark. Magneto coils that last. And a secondary power system for lights and accessories.
WHAT ABOUT THE CRANK
The crank
I am seeing 2 options here.
A) Since we want better bearings on the crank big end and we want to use the PUCH top end a new or modifyed crank would be great.
It is possible to use the chineese crank and modify it by using a Puch connecting rod but we also would benifit from using the Puch Electrical System.
Since were machining cases we can make the cases to take the puch electrical system. We could also make the cases universal so they could use the Puch Magneto or the HT Magneto. The problem is the crank needs to be universal as well. We would have to make the magneto end of the shaft changeable.
To be Continued.......................
