Stroker built with ATC parts

[WILL_S]

Hi
Been lurking here for ages and using all the cool info to help me build a stroker motor
Thought i would throw up a few pics of a motor build now i have finished it.
The plan was to build a 170cc, but one of the barrels had a issue so i went back to a more reliable 150cc for now.

It started with scoring a nos helm and son atc110 58mm stroker crank.



Then i started playing around with different piston combos in the 55mm size for a 138cc using 110 and 125 barrels





But i want bigger power so two 61mm barrels were knocked up to take a couple of different pistons





This one below is going on a stock 49.5mm stroke


A 90 roller cam was used to work out how to turn a 125 cam into a roller







Cases bored



I have to confess this motor isn't going into a trike,if i had more time iwould love to build a little 70 with a bombed motor.

To be cont.....

[HairyJR]

Looks like a great project, question I have is what boring tool was used to bore cases? Looks like a hole saw.

"HJ"

[WILL_S]

Looks like a great project, question I have is what boring tool was used to bore cases? Looks like a hole saw.

"HJ"

Um yes holesaw .You can't just fire it up am bang it in,there is a technique .I have done about 5 sets of cases this way from 110 to take 125 barrel right up to the 61mm big bores.I have built a few tools for working on these motors but a case borer is on the too do list.

Cases bored for 61mm


Valve spring compressor



Piston holder for machining

[WILL_S]

Had a issue with the crank being 10mm to wide for my application,something to do with a pullstart pushing the flywheel out.
Made a spacer plate to space the stator cover,from what i have read you blokes normally space the barrel for strokers.No dual range for me and also running 12v with ign pickup at the flywheel.That's atc125 crank in the pics with the spacer.

[WILL_S]

Then the shifter won't clear,easy fix without cutting and extending shifter shaft.

[WILL_S]

Bottom end sorted.
The top end i think might interest any old schoolers who want build 110 strokers or big bores.
The first combo was with a gy6 61mm forged piston for 170cc,more time is needed to sort a few things on that,piston to deck height is right with no spacer plate if you use a ct110 barrel and atc125 head.
I needed another motor quick so i took a atc125 barrel and bored it to 57mm then decked it back to 110 height, more was taken off the top of the barrel than the bottom.The oil gallery gets recut.A standard cam chain and no spacer required.

61mm


57mm



Valves won't hit so no extra clearance was required on the piston.Had to drill some oil holes in it.

[YTZ drew]

Is that a Trail 90 with 2 rear wheels in the background, or an optical confusion on my part? Either way, cool project! I like your piston holder for the lathe chuck, very clever!

[Joseph Farrow]

Excellent Work!
Where did you get your larger sleeve?

[ironchop]

Awesome build, great thread. Subscribed.

Sent from my Z998 using Tapatalk

[WILL_S]

Is that a Trail 90 with 2 rear wheels in the background, or an optical confusion on my part? Either way, cool project! I like your piston holder for the lathe chuck, very clever!

Another project trail 110 converted to a fatcat.

[WILL_S]

Excellent Work!
Where did you get your larger sleeve?

FPM

[oscarmayer]

Nice. You look like me 2 years ago messing with China motors for my son's racing.


Sent from my iPhone using Tapatalk

[Daddio]

Bottom end sorted.
The top end i think might interest any old schoolers who want build 110 strokers or big bores.
The first combo was with a gy6 61mm forged piston for 170cc,more time is needed to sort a few things on that,piston to deck height is right with no spacer plate if you use a ct110 barrel and atc125 head.
I needed another motor quick so i took a atc125 barrel and bored it to 57mm then decked it back to 110 height, more was taken off the top of the barrel than the bottom.The oil gallery gets recut.A standard cam chain and no spacer required.

61mm


57mm



Valves won't hit so no extra clearance was required on the piston.Had to drill some oil holes in it.

So................., how did this turn out? Curious because I'm getting ready to start building a couple stroker engines.

[WILL_S]

So................., how did this turn out? Curious because I'm getting ready to start building a couple stroker engines.

Turned out great.
10000+km on it now and getting stronger,that stroker crank must be loosening up
Got some bits coming to build 125 cranks into 58+ strokers, will probably be used in my new build with 185/200 top end

[atcmatt]

Where in Aus are you Will?