New Member Big Bore Stroker Question By dirtrider1219 (Read 2,076 times)

[czmdiver]

Oct 25, 2015 13:58:28 GMT -6 cyborg said:

To achieve zero deck you must be running special pistons with raised pin location and shave the crown too or you can get it with the piston?

This is mostly correct. and I should have pointed this out,  Borg's on the gas.
I can make the Custom Piston with the Correct Pin Height and that Will make my Piston Timing edge correct at Zero Deck.
Then there will be no machining of the top of the piston. Given the Cylinder is the Correct Blue Print Height, seldom are, then you alter the zero deck with different Base Gasket Thicknesses.
The Slipper style skirt will need little to know attention.

[dirtrider1219]

This is great info! So for a more reliable street engine, it would be better to get a Taiwanese made stock-stroke crank, and a 63mm bore? Or will the stock crank hold up ok with the 63mm?

[cyborg]

I meant to say " or can you get it with the piston?",,, without shaving the crown,,,,,in my mind I figured you could juggle the pin height enough to cover the spread but I've been wrong before

[cyborg]

What we did in the " old days" was offset ground the crank rod journal that moved center out giving us stroke and still use the stock crank,,,ran a rod with a smaller big end ,,

[czmdiver]

Oct 25, 2015 15:21:37 GMT -6 dirtrider1219 said:

This is great info! So for a more reliable street engine, it would be better to get a Taiwanese made stock-stroke crank, and a 63mm bore? Or will the stock crank hold up ok with the 63mm?

There is a Displacement argument that can be made, and its a valid one.
I'm happy to provide the information so you know what you in for.
Your going to have to make your call.
Stock crank should hold up as well as a stroker.

[dirtrider1219]

Interesting info cyborg, although with these scooter engines I don't think it would be worth the hassle or cost to ground the crank like that. And I'm not even sure you can order rods with a smaller big end. Interesting nonetheless. So these guys that do the +8.2mm strokers and 232cc get away with it because they're using a 67mm bore which helps the rod angle?

[dirtrider1219]

Thanks diver. I'm leaning toward the original stroker kit because I love displacement   I was thinking about ceramic coating the piston as well. Never tried it but have heard good things about it and should help reduce friction from the aggressive rod angle. I will probably start a new build thread and I can also document any differences between the p engines and non p engines. 

[dirtrider1219]

Any information you're willing to give Diver, I'm all ears. If you want to post it here or i can PM you, totally up to you. To everyone in this thread

[czmdiver]

Of what we have available to us from MFG's I think the Taida Line is the best of what's out there.
Pick the correct Piston , Even with the lil Pop up Dome is Lighter. the Dome Rise I think is .110
The Scales don't lie





A Taida Plated Cylinder on the right, Iron Bore NCY on Left. The Plated Bore has many benefits over Iron, Iron Barbaric

[czmdiver]

Of what we have available to us from MFG's I think the Taida Line is the best of what's out there.
Pick the correct Piston , Even with the lil Pop up Dome is Lighter. the Dome Rise I think is .110
The Scales don't lie, The Lighter Piston assy will be a little easier on the Crank.





A Taida Plated Cylinder on the right, Iron Bore NCY on Left. The Plated Bore has many benefits over Iron, Iron Barbaric

[jct842]

I sure wish they made a similar to a gy6 in a slightly bigger aircooled case around 200 cc. About double the size it started as. Guess in other parts of the world where they sell scooters the speed limits are lower than in the good old USA. In my opinion a gy6 is not a 55mph ride. I could get around 63-65 out of mine but it still was a 45 mph scooter....where it was happiest running anyway.

Punching it up ifrom the original 100 or 110cc's up to where a lot of them are now is not leaving much head room on engine reliability. I do like an air cooled for the simplicity and ease of repairs and the cost of such.

[cyborg]

Oct 25, 2015 17:51:15 GMT -6 dirtrider1219 said:

Interesting info cyborg, although with these scooter engines I don't think it would be worth the hassle or cost to ground the crank like that. And I'm not even sure you can order rods with a smaller big end. Interesting nonetheless. So these guys that do the +8.2mm strokers and 232cc get away with it because they're using a 67mm bore which helps the rod angle?

Being a antique myself there were no off the shelf items such as these stroker cranks ,,,Pistons in every size that you could just buy,,,,,,ect,,,so we used to pal up with racers and good ol hotrodders,,,,,we made the parts we needed,,,,,

[cyborg]

Oct 25, 2015 18:20:23 GMT -6 jct842 said:

I sure wish they made a similar to a gy6 in a slightly bigger aircooled case around 200 cc. About double the size it started as. Guess in other parts of the world where they sell scooters the speed limits are lower than in the good old USA. In my opinion a gy6 is not a 55mph ride. I could get around 63-65 out of mine but it still was a 45 mph scooter....where it was happiest running anyway.

Punching it up ifrom the original 100 or 110cc's up to where a lot of them are now is not leaving much head room on engine reliability. I do like an air cooled for the simplicity and ease of repairs and the cost of such.

Taida does,,,as far as scooter parts they are the best,,,,,Dan has a kymco built 155cc Yamaha smax that goes over 80 mph right out of the box , stock no mods,,,,65 mph all day long,,,not stressed

[czmdiver]

Oct 25, 2015 17:58:30 GMT -6 dirtrider1219 said:

Thanks diver. I'm leaning toward the original stroker kit because I love displacement   I was thinking about ceramic coating the piston as well. Never tried it but have heard good things about it and should help reduce friction from the aggressive rod angle. I will probably start a new build thread and I can also document any differences between the p engines and non p engines. 

You mean a Ceramic Thermal Barrier Applied to the Dome correct?

[dirtrider1219]

Check this out. http 200cc pre-built ://www.scrappydogscooters.com/125_150cc_Performance.html

Scroll down to the bottom. I just sent a few questions asking about it. Only issue is it's a short case. Would be fun to play around with neutral though