Custom 70cc engine build

Is it worth it or stupid?

  • YES

    Votes: 20 62.5%

  • Hell no

    Votes: 2 6.3%

  • Kinda

    Votes: 4 12.5%

  • YES

    Votes: 3 9.4%

  • Nah I'll pass

    Votes: 3 9.4%
  • Total voters
    32
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dougstar said:
Buy new clips??
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I want to get the opinion from Sean or maybe @Polar_Bus who have done porting or know alot about this kind of stuff (or at least I think they know) ? then I'll make my move, the advantage to modding the case though is if I need a new piston, I can just drop it right in, no modifying cuz it's already done, oh and a plus is that I will only need to buy a rotary tool and some new oring cord (not gunna reuse the old stuff because it's already been crushed by torqueing the case)
 
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Grind the case. Grinding on the piston can effect your port timing. You don't want to do that. Sorry mate.
And welcome to porting 101? smooth smooth smooth. Make it a nice radius but try not to take too much off as it will mess with your case volume.
 
Seandonato73 said:
Grind the case. Grinding on the piston can effect your port timing. You don't want to do that. Sorry mate.
And welcome to porting 101? smooth smooth smooth. Make it a nice radius but try not to take too much off as it will mess with your case volume.
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Oh didn't even think about port timing, yeah I don't wanna change that. I'll grind the case ?
 
Found my candidate for a rotary tool, https://www.homedepot.com/p/WEN-101-Piece-Rotary-Tool-Kit-with-Variable-Speed-2307/203736986 had good reviews, looks like a good deal and sounds 30k rpm apparently. I'll be giving this a go ? tho I'll order it thru Amazon prime so I can have it in 2-3 days vs home Depot shipping is 5-8 days or something like that ? and I'll get some diamond grinding bits cuz those are for steel so it should go through aluminum just fine ? or if I can find me some tungsten carbide ones I'll get those instead ?
 
Z.hb71 said:
Found my candidate for a rotary tool, https://www.homedepot.com/p/WEN-101-Piece-Rotary-Tool-Kit-with-Variable-Speed-2307/203736986 had good reviews, looks like a good deal and sounds 30k rpm apparently. I'll be giving this a go ? tho I'll order it thru Amazon prime so I can have it in 2-3 days vs home Depot shipping is 5-8 days or something like that ? and I'll get some diamond grinding bits cuz those are for steel so it should go through aluminum just fine ? or if I can find me some tungsten carbide ones I'll get those instead ?
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They go through aluminum & steel ,but they burn up quick!

I got my Dremel almost 30 years ago ,at first ,I could not think of one thing to use it for ,but
when I got it ,I worked it nearly to death!....LOL
 
Seandonato73 said:
I have just what you need. Mine showed up today. I tried them out a bit at work. Loved them.
DLtools 20pcs 3mm Shank Solid Tungsten Steel Carbide Rotary Burr Set,Dremel & Rotary Tool for Drilling Carving Engraving and Woodworking https://www.amazon.com/dp/B07SVX7SDD/ref=cm_sw_r_cp_apa_i_ymplDbBYGDF06
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Carbide burrs it is ?
cbaker65 said:
They go through aluminum & steel ,but they burn up quick!

I got my Dremel almost 30 years ago ,at first ,I could not think of one thing to use it for ,but
when I got it ,I worked it nearly to death!....LOL
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You can bet money that I'll use the hell out of it!
 
Z.hb71

The width issue may also be because crank is too wide where it goes against the bearings or a big radius in the corners. Also the bearings may or may not have a radius where the crank shaft goes through it. This will hold the cases apart like you are seeing if everything is seated correctly. You can also grind the radius in the inner bearing races where radius on the crankshaft to crank web is hitting more if needed. We had to do this with our engines when we used a certain bearing in them.
 
TODD said:
Z.hb71

The width issue may also be because crank is too wide where it goes against the bearings or a big radius in the corners. Also the bearings may or may not have a radius where the crank shaft goes through it. This will hold the cases apart like you are seeing if everything is seated correctly. You can also grind the radius in the inner bearing races where radius on the crankshaft to crank web is hitting more if needed. We had to do this with our engines when we used a certain bearing in them.
Click to expand...
The crank goes in fine, you just have to use alot of lube. The crank is the exact same as Alx (the people who made the crankcase)
 
Hey Z, I've been following this thread for a while. Very impressed with your stick-to-it attitude despite the many challenges! I'm really excited to see where this project goes.

If you plan on using a rotary tool for any length of time, you might want to look into getting a Foredom flex shaft with a foot pedal (stick with the Foredom brand). They're not cheap, but they're a worthy investment. I use this one in jewelry making constantly (https://www.amazon.com/Motor-Plastic-Pedal-Speed-Control/dp/B00CFSBO0A/) and it blows my dremels out of the water in every respect. They have a huge amount of torque compared to the smaller options. You'd be surprised at how accurately you can cut metal using a tungsten bit with higher torque, lower speeds and a foot control.

Sorry, didn't mean to thread jack, I'm not a rep for the company or anything, you just seem like the kind of fellow who would be able to do some awesome things with the right tools.
 
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