Flywheels
- Thread starter Howardgf
- Start date
there are more than that when you add in stroke length and conn rod type, also large vs small main bearings & cylinder deck heights & port maps
my advice is that it is cheaper/easier to buy a new motor than to mix & match components
nice project for the dedicated hobbyist tho
my advice is that it is cheaper/easier to buy a new motor than to mix & match components
nice project for the dedicated hobbyist tho
I fully agree... Even tho I buy bottom ends from one source, cylinders and pistons from another, and the head from yet another... It can easily cost upwards of $250 or even $300 just to build one this way, but it sure puts a smile on your face when you crack the throttle....
Thanks guys. I have a motor kit from Banggood that's going in my first personal build. I'll want a spare top end in case this one eats its self before I get to 30k miles, as one fellow claimed(I know...). I'll just build a separate lower end as an experiment, since the parts are so cheap, to see what careful workmanship, better bearings, etc., can do for vibration and longevity. I'll just measure my motor when I replace all the bolts and studs. I'm guessing the top end differences are due to the A or B pistons? We'll see. H.
Mzmiami on ebay has some really nice top end kits right now... I bought 4 of them recently and their quality is tops... nice thick cast fins and huge transfer ports, the exhaust ports are nice and wide on these as well... just he sure to check which piston you're currently set up for before buying...
Here's the link for the 40mm type b kit, he also has the type a kit and sells the parts individually as well as having the 32mm or 40mm cylinders available by themselves or as a top end kit, and the 40mm kits come with the 40mm intake so converting over to 40mm is nice and easy. Both the 32 and 40mm cylinders are excellent quality with the wide exhaust and transfer ports... http://www.ebay.com/itm/MOTORIZED-B...ON-KIT-AND-40-Mm-INTAKE-MODEL-B-/281772004785
Here's the link for the 40mm type b kit, he also has the type a kit and sells the parts individually as well as having the 32mm or 40mm cylinders available by themselves or as a top end kit, and the 40mm kits come with the 40mm intake so converting over to 40mm is nice and easy. Both the 32 and 40mm cylinders are excellent quality with the wide exhaust and transfer ports... http://www.ebay.com/itm/MOTORIZED-B...ON-KIT-AND-40-Mm-INTAKE-MODEL-B-/281772004785
please take a minute to read thru this thread (and maybe some others) before starting
http://motorbicycling.com/showthread.php?t=52554
http://motorbicycling.com/showthread.php?t=52554
Well, I already had read this, took me more than a minute tho. Guess I'm slow. Anyway, thanks for taking the time with a newbee. This whole thing boils down to wrist pin height, and stroke, no? I'll measure mine when I take it apart. I had thought one 66cc upper repair kit was the same as all others. Thanks for stopping me. H.
There are a few geometry differences that need to be addressed, especially if mating up one of those kits I mentioned to a 38mm stroke engine, but one should Always measure the port hight as well as the piston location in the jug at TDC as some compensating may need to e done either by shaving a milimeter or so off the cylinder deck or shimming the base to get the ports where they need to be. If your building on top of a 40mm stroke crank, you still need to double check the port hight and piston deck hight to prevent building a super low compression engine or end up with a piston sticking 1mm or more above the deck.
I've built one engine by mixing and matching that ended up with the piston sticking out about 1mm above the deck but was able to use it by adding a .040" shim at the base.... there was a bit more I had to do to keep the ports where they needed to be as well as keeping the squish clearance acceptable etc.
I do have the tooling and resources to do all of this but it would be quite tricky for the home hobbiest with basic or limited tooling, it can still be done but will become a lot more labor intensive if a base shim needs to be made...
I've built one engine by mixing and matching that ended up with the piston sticking out about 1mm above the deck but was able to use it by adding a .040" shim at the base.... there was a bit more I had to do to keep the ports where they needed to be as well as keeping the squish clearance acceptable etc.
I do have the tooling and resources to do all of this but it would be quite tricky for the home hobbiest with basic or limited tooling, it can still be done but will become a lot more labor intensive if a base shim needs to be made...
Thanks Dave, I agree with you. In days LONG past we called base shims 'Fish plates'. They let us put Harley flathead 80 wheels in 61, and 74 cI (that's INCH,not cc) cases to make strokers way before S&S, and others started selling them. Again, many thanks, H.
Yup... I'm familiar with the term fish plates.... not really a need for them nowadays with S&S, Andrews, Edelbrock, Red Shift, and several others who make cranks and cylinders that'll fit just about anything... and now you can get pan heads and knuckle head replicas that'll fit in the modern frames with the late model 6 speed trannys etc... they look exactly like the originals but run like a beast thanks to nearly double the cubic inches and hotter cam's etc...
No kidding... One of those Ultima pan or knuck replicas can cost upwards of $10K, they look, sound, and run like the originals except a LOT more power... Thewse things are nice, cheap, and still a lot of fun.
Man I remember when you could buy valve covers to make your panhead look like the newer shovel head... man times have changed...
Man I remember when you could buy valve covers to make your panhead look like the newer shovel head... man times have changed...
yeah, sad times for us (We?) traditionalists. Make the now look futuristic, and the new look old style. I will probably make this build punkish (Steam, or diesel) cause I love old timey stuff. I guess cause I'm pretty old timish, myself. Then too, I want to 'Stick it to the bike shop man'. Hence the Huffy build. Ever ask those guys about bearings for a Huffy? Here in the high desert, bicycling is very popular. LOTS-O-SNOBS. That's why I appreciate this board so much. Oh well, thanks for the consideration. H.
I know what you mean there.. went into a bike shop to see if they had the rebuild parts for my Noleen front end and the guy looked at me like I didn't know what I was talking about, I explained they used to come on the Proflex mountain bikes, still just got a dumb look... Then after he thumbed thru a catalog for about 5 minutes he came back and told me there was never a Noleen front end so I told him some of them are Noleen and some are Girvin but they are the same and all the parts interchange... He told me again he's been working on bicycles for over 30 years and there are no forks with the Noleen or Girvin brand name. I told him, that's funny because I got one and got another few I'm watching on ebay right now... The guy was very arrogant and snobbish like I didn't know what I was talking about but he did have some nice disc brake setups under the glass and I was asking him if he sold the disc brake hubs so I could convert mine to disc, again he told me it was impossible to convert a non disc brake bike to disc... I didn't bother telling him how many of them I converted, but before I left I saw a nice mountain bike on his used rack and made a comment about how easy this one would be to put an engine in, which I could see got his blood boiling before I finally left his shop... Anyway, I got a nice Specialized mountainbike with a rebuilt (thanks to ebay and new old stock items) Noleen front end that's converted to front hydraulic disc brakes and some day when I get the time to finish this build I would love to ride it up to his shop just to look around a little more....
