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Post by oldgeek on Nov 3, 2020 6:59:02 GMT -5
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Post by Kenho21 on Nov 3, 2020 7:03:45 GMT -5
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Post by pinkscoot on Nov 3, 2020 10:18:15 GMT -5
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Post by Kenho21 on Nov 3, 2020 10:54:52 GMT -5
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Post by Kenho21 on Nov 3, 2020 10:55:55 GMT -5
From what I can find, it looks like the only case cutting tools out there are to cut the cases where the cylinder sleeves slide in, nothing for the crank area. Or does that cutting tool do both?
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Post by 90GTVert on Nov 3, 2020 12:33:14 GMT -5
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Post by Kenho21 on Nov 3, 2020 12:37:48 GMT -5
I just watched that video lol. Crazy to think that no one has made a crank area boring tool. It's a pretty popular thing to do. Seems like Buzetti or one of those type companies would've been all over this. Looks like I have to decide if I want to cobble my own something together or go with the carbide method... |
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Post by 190mech on Nov 3, 2020 18:41:54 GMT -5
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Post by Kenho21 on Nov 3, 2020 21:41:07 GMT -5
Considering I was going to be using your design as a major reference for whatever I would’ve come to with, I’d be greatly appreciative of the favor. Saves me a lot of effort from making one and will probably achieve a much better result than I could have accomplished on my own. I’ll PM you 190mechThank you! |
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Post by 808ministroke on Nov 21, 2020 2:02:11 GMT -5
Hey You're telling me that the Athena 43 mm crank is not a standard style Mini stroke crank? What I mean by that is all the Mini stroke or cranks I've seen and have owned including one on building right now get their extra 2 mm stroke simply by putting the conrod closer to the edge of the crank by 1 mm What this does is it allows the piston one mm lower at bottom dead center and 1 mm higher at top dead center, So for example the AB Mini stroke crank I have in my upcoming Air cooled build has no machining done to the case the stroke is not 39.8 rather 41.8. It seems really pointless to have to machine a case to get only an extra millimeter then a Mini stroke crank allows. |
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Post by oldgeek on Nov 21, 2020 6:49:47 GMT -5
Hey You're telling me that the Athena 43 mm crank is not a standard style Mini stroke crank? What I mean by that is all the Mini stroke or cranks I've seen and have owned including one on building right now get their extra 2 mm stroke simply by putting the conrod closer to the edge of the crank by 1 mm What this does is it allows the piston one mm lower at bottom dead center and 1 mm higher at top dead center, So for example the AB Mini stroke crank I have in my upcoming Air cooled build has no machining done to the case the stroke is not 39.8 rather 41.8. It seems really pointless to have to machine a case to get only an extra millimeter then a Mini stroke crank allows. The stroke of the crank is irrelevant to what I was talking about. Its simple, if the particular crank you want to use in your motor will not fit inside the cases, you will have to remove material until it will fit. So remove enough material to give you 1.5-2mm clearance around the crank webs. One thing to remember, when they manufacture a crank with a longer stroke, they are moving the pin closer to the outer edge of the crank webs. If they do not increase the diameter of the crank webs the crank will be weaker. Sometimes they use a smaller diameter big end pin so there will be more meat at the edge of the webs. Not really a good trade off IMO. |
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Post by Kenho21 on Feb 23, 2021 19:15:43 GMT -5
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Post by ryan_ott on Feb 23, 2021 20:17:07 GMT -5
I ran that briefly few years ago and used a C16 and it performed pretty good. The squish was too large with the supplied head so used a Polini head from a cast kit to get it close.
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Post by Kenho21 on Feb 24, 2021 7:15:44 GMT -5
I ran that briefly few years ago and used a C16 and it performed pretty good. The squish was too large with the supplied head so used a Polini head from a cast kit to get it close. Right on. C16 was my first inclination. I had the same issue with the 70cc Athena kit and also used a Polini head to get the squish down to ~0.7mm I believe. I just remembered that I bought an extra Polini head "just in case" as well. Already ready to go for the 80cc! |
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Post by Kenho21 on Mar 20, 2021 11:14:23 GMT -5
We shall not discuss the inspiration of my color choice...  |
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