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Post by Dandy Dan on Oct 19, 2005 6:54:21 GMT -5
I just have a couple big bore questions I've been saving up. Hopefully someone knows the answers:
1) I know a good local shop that does boring etc but will it be hard to find a shop that has the tools to bore out a cyclinder that small?
2) Does the cylinder need to be replated? Is this expensive?
3) What about our compression ratios? With a stock ratio of about 12:1 that's 49.4cc crammed into 4.1cc. If we go to 58cc we'd still be cramming it down to 4.1cc cuz the head isn't modified so our compression ratio jumps to just over 14:1.
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Post by chanito on Oct 19, 2005 10:16:24 GMT -5
1.-Your best place should be a motorcycle place or a big machine shop
2.-I do not know yet, but more than likely not, it depends on the rings and what finish they need, however having it re-coated would reduce friction and give us even more extra power, so i will have to see if they can get us the rings that would give us that possibility, coating will limit the amount of places that can do this machining but is a better option
3.-The good thing about a bigger bore over stroking is that the same millimeters that give us a bigger displacement are there at the top of the travel so the volume at the top of the piston travel also increases keeping the compression ratio about the same, in the stroker the piston goes further up and further down creating a compression ratio increase, not our case.
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Post by Dandy Dan on Oct 19, 2005 10:58:02 GMT -5
1) Ok, the place I'm thinking of taking it to is a big motorcycle dealer that sells all the major brands and advertised on their site that they do boring etc. (Their site is www.twowheelmotorsport.ca if you click on 'machine shop services' they list a bunch of boring, sleeve replacement, replating etc. so I should be good, the $$ is a bit high but that is Cdn.$ so US it's about 80% of that. 3) (Compression Ratio) I could be wrong but this is the way I think of it:  Doesn't the piston rise right to the top of the sleeve so all the space that the air/fuel is compressed into is in the head? And if so, since the head isn't being modified the 4.1cc of space remains unchanged but now 58cc's are being squashed in there instead of 49cc. The only way to not increase the compression ratio (it seems to me) is either to modify the head OR if the piston doesn't come all the way up then there would be some additional space above the piston but I think the Ruckus piston rises right to the top of the sleeve so the additonal 3mm of diameter would just be butting right against the head...Please explain. |
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Post by chanito on Oct 19, 2005 12:02:53 GMT -5
Nice picture, but even if the piston runs to the top of the bore, the shape of the crown has a lot to do with that free space (the piston top is not flat) so the piston top (crown) is what decide the amount of free space at the top of the travel, but we have what i think is 1 millimeter of free space plus the thickness of the head gasket, which we will have custom made to avoid any such problems  |
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Post by Dandy Dan on Oct 19, 2005 12:26:53 GMT -5
You're a god, thanx for clearing that up. Would bumping our compression ratio up a bit to say 13:1 be a good/faster idea?
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Post by Backlater on Oct 19, 2005 22:50:33 GMT -5
Would cooling be an issue ? Also the connecting rod ? Is the stock rod adequate for the mod ?  |
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Post by chanito on Oct 20, 2005 4:39:11 GMT -5
8-)Cooling should be ok, as we are the system is adecuate, it might be a good idea to get a bigger capacity overflow tank just to be on the safe side, but it should be ok.
The bottom end (connecting rod and crankshaft) are over design so we are super safe on that, also we have a big carb so that is more than plenty to flow the extra cc's
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hadoq
Ruckster
Posts: 161
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Post by hadoq on Oct 20, 2005 5:21:17 GMT -5
ok, I might be back in the game as our techie knows a place where they can bore out the cylinder.
tho there would be a few question (sorry if they were answered, gonna re read the whole thread after I post this message)
you're gonna take the 4 valve engine's piston as a base ?
the cost would be about 200 bucks right ?
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Post by chanito on Oct 20, 2005 6:15:53 GMT -5
I will love to have a 4 valve piston, but i do not have one yet, hope you can help me with it, but i can get a 2 valve piston so i will try to do that first and then if i get a 4 valve piston do that too
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hadoq
Ruckster
Posts: 161
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Post by hadoq on Oct 20, 2005 9:19:51 GMT -5
I have to call the dealer tomorrow for my frame (want to buy an empty frame) gonna ask bout the piston's price.
ps: the main techie just mentionned a supercharger he could potentially mount on the zoomer ^^ I'll give you news in a few weeks.
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Post by chanito on Oct 21, 2005 18:39:05 GMT -5
:)Looking forward to an update  |
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Post by timberwolfmadcat on Oct 25, 2005 22:30:19 GMT -5
ooh supercharger, any ideas on the cost of this 4 Valve conversion, it sounds expensive, id be totally happy with just a 2 valve, but WTH?
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Post by chanito on Oct 26, 2005 20:50:46 GMT -5
8-)Ok Zoomzoom has finded a nice use engine on Ebay, i plan to buy it so i can do this project and have a block already bore out, so if some one is interested we can do a core block program, so you can get the block with the machine work already done on an exchange basis, so please let me buy it and do not spoil it for me |
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Post by Dandy Dan on Oct 26, 2005 21:00:12 GMT -5
Ahhh, I really want that engine. I've already got it in my watch list. Your cause is more noble that mine though. I want it so I can eliminate the downtime of working on my engine plus my engine has 24,000km on it and somethings aren't quite right including a few stripped holes and an oil look.
How about this: You buy it but I'll buy the drive arm piece off of you? I'd love a new one cuz that's where most of my stripped holes are (some my fault, some my dealers) and I could use a new final reduction with all new bearings etc. I want the whole engine but I'm willing to let it go to you as long as you promise to bring me a big bore piston some day. I was gonna bid up to 250$ US.
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ZoomZoom
Ruckster
'05 Ruckus, '97 Polaris 400L 4X4
Posts: 251
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Post by ZoomZoom on Oct 26, 2005 21:14:20 GMT -5
I told chanito because I was thinking about bidding on it till I read the part that he only ships to the lower 48 states,  So I thought chanito could use it for the piston upgrade, maybe inspire him. |
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Post by chanito on Oct 27, 2005 7:04:28 GMT -5
:)You guys are the best, and sure DD i can sell you the gear case with the variator, but you need to sell me yours so we can see if they can be modify to use roller bearings in the case instead of those flat washers, and to make the necesary measurements for swaping the rear axle from a metro so we can have that 50 mph capability  |
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Post by Dandy Dan on Oct 27, 2005 7:13:55 GMT -5
The metro uses roller bearings??? If this all worked out and if you wanted, I could head up the final reduction metro conversion, bearing change etc. aspect of things if you wanted to stay focuses on the piston/boring but if you'd rather do it all that's cool too. I have been in the final reduction a few times now so I am getting to know things in there pretty well.
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Post by chanito on Oct 27, 2005 10:38:27 GMT -5
 No, i want to know how much room is in the case so we can adapt some roller bearings to the case, so we can use that instead of those washers That rear end is the only weak point in the ruckus, even the brakes are adequate, small diameter wide area, they require less effort than bigger diameter narrow brakes, obviously having front hydraulic disk would be great. Also it will allow us to see any potential problem with the metro rear axle
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Post by Dandy Dan on Oct 27, 2005 10:46:30 GMT -5
Ok sounds good. I am a big fan of the stock brakes although front disc would be cool too. Just yesterday I was driving around marvelling at my brakes doing 'stoppies'. I was actually doing real stoppies not just deweighting the rear end and letting the suspension unsag because I could kinda push the rear end out sideways a bit so it would chirp when it touched down.
Anyways, I'm really stoked for this whole project. I'm working hard right now to get a tach. I love the Jr. Dragster one for it's 10k redline, quality and size but I'm still hoping to find something that matches the other gauge a bit better. If I buy an aftermarket gauge which is both a speedo and a tach and I'm going to have issues with the speedo cable? I mean is our speedo cable kinda designed for just our speedo or is there some sort of common system where I could screw it into another motorcycle speedo?
Anyways, I let you
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Post by chanito on Oct 27, 2005 16:32:12 GMT -5
8-)Usually the aftermarket speedo uses a pulse generator, you install a magnet in the wheel and a sensor in the fork, when the magnet pass by the sensor it generates a pulse, the small computer in the speedo counts these pulses then you input your tire size in the small computer in the speedo, and there you go a nice speedo ;D, you can even install a different tire and wheel combination and as long as you did not loose the instructions you can input this new size and the speedo will adjust to the new size and remain accurate |
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