Custom Machined / Performance of a higher level

Discussion in 'Performance Mods' started by 210061741, Oct 22, 2010.

  1. 210061741

    210061741 Guest


    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.

    Earlier this year i purchased a Puch Moped Cylinder Kit and High Comp Head from Treatland.

    Cylinder Kit I have:

    High Compression Head I have:

    Reed Block I have:

    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. :cool2::cool2::cool2:
    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.


    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 :rolleyes7:
    And best of all Reliability.

    Therefor Benifits divided by cost = 4 me it is wort it.


    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.....:ack2:
    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.:whistling:

    Pcs break off and the threads strip out so easily it's rediculous.:ack2:

    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.



    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.

    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.


    But all in all the clutch is the last thing i'm worried about.


    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.


    The crank :ack2:

    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.......................

  2. 5-7HEAVEN

    5-7HEAVEN Guest

    Good luck in your pioneering experiments, sir. You are doing the field of motorized bicycling great justice.

    Don't let anyone on any forum know where you work.:whistling:

    Could you make custom cylinders for GP460 engines?:detective:
  3. 210061741

    210061741 Guest

    You could make custom cylinders but i think it would get expensive when it came to crome plating the bore or having the sleve made. Anything can be done it's just a matter of how much it's gonna cost.
    It would be cheaper to buy a cylinder and machine the ports.

    In a nutshell im basically taking the Engine Parts from a Puch Moped Engine and putting them in a set of cases machined to fit the bicycle.

    Scratch the idea about the universal electrical system. It just wouldn't work out.

    As far as the crank and bearings we could use this.

    And since were using the puch crank we can use the puch electrical system without any snags. Which is a nice option cause they make some nice electrical systems.

    If you want to go nuts and you got the cash this is about the best.

    A little step down from there.

    Yes if you want it can be programmed.

    By golly now were cookin.

    But do the math and realize it's not cheap.

    Were at $300 for the top end and carb.

    about $130 for the crank. The crank will also need some machining on 1 end.

    Another $200 for the electrical system

    So were about 650 bucks now.

    At least we can buy it a pc at a time and will have a 1 of a kind machine that will last forever. Im guessing it'l be fast and furious.
  4. 210061741

    210061741 Guest

  5. 210061741

    210061741 Guest

    Ok i found the basic dimensions of the Puch Crankshaft.

    Click the image on the far right at the bottom.

    compared to the stock HT crank we can see that the puch crank is approximatly 1" wider on each side. If we machine the clutch end of the shaft to use the HT clutch it would be the same length on that side. But still 1" wider on the magneto side. At any rate i plan to move the drive sprocket on the motor out at least 3/8" So we will have an engine 1 " wider than a HT and it will still be just about centered ending up approximatly 1/2" wider per side.

    In a tight fit situation this could cause a problem with the clearence between the crank arms of the bicycle. That all depends on where the engine sits in the frame.

    But were making a set of cases here so we have options.
    And the best option i can think of is to angle the cylinder forward more.

    Ideally if we set the cylinder correctly we can have a cylinder that runs parallel to the downtube of the bike. This will allow the engine to sit a bit higher in the frame. Enough to be out of the range of the crank arms. As a added bonus we could then add a mount between the cylinder and the downtube and also a mount between the cylinder and the top tube of the bike. Giving us a total of 4 mounting points for the engine. That is about as solid as you could posiblly get. Now of course im looking at a Mountain Bike. A beach cruser setup would need to be a bit different.
  6. 210061741

    210061741 Guest

    A great link to the bearing and seal sizes.

    From this information we can figure out what sizes to make the bearing housings in the case halves. We can also spec out Bearing RPM and Load Ratings.

    Remember we are using a E-50 Crankshaft.
  7. Turtle Tedd

    Turtle Tedd Member

    Rich..congrats on job..and now you have expansive machinery at your disposable for your own projects ..I sure do miss that..good stuff coming I predict
  8. 210061741

    210061741 Guest

    Well i'm sure i will only be able to use the equipment on my own time when it's available.
    But that's better than not at all.
    If the prototype works out good, maybe i can work something out with the company to manufacture a few runs. You never know. They have quite a few machines to keep busy.
    One of the companies main customers is SKF.
    So i'll be manufacturing lots of bearings.