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Post by oldgeek on Oct 22, 2014 21:52:34 GMT -5
I am still waiting for parts to arrive so I can get this back together. Feels weird not having anything but a stock scoot to ride. LoL! Anyway, I cut some new reeds from .30 carbon fiber to replace the fiberglass reeds that were in it.
I have been looking at the durations for the replacement crank and piston. I am going to try to squeeze a bit more performance from this set up since I have a larger pipe to use. Looks like with 1 thick metal base gasket, sandwiched between 2 standard base gaskets, I can get the exhaust duration up to 188 and the transfers at 130. I plan to profile the top of the piston to get the exhaust duration up to 190. The piston ends up just below the deck <1mm. I think if I use the streetrace head compression will be too low, so I am hoping I can use a different head that I have after modifying it a bit to get the compression back up where it belongs around 170? Squish will be somewhere around 1mm I am guessing.
Any input, suggestions are appreciated!
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Post by jareeb on Oct 22, 2014 22:53:07 GMT -5
i was going to try this idea in a sort. gona get a c16 pipe and better crank with port work, try to make some more power.
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Post by 2TDave on Oct 23, 2014 5:21:55 GMT -5
Sounds like a good plan OG. The 130 intake is what John suggested to be. I think you could go a little higher on the exhaust. With the iron cylinder you could open the exhaust port and get it to 192 or so. What pipe is it and what rpm range?
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Post by oldgeek on Oct 23, 2014 5:56:55 GMT -5
Sounds like a good plan OG. The 130 intake is what John suggested to be. I think you could go a little higher on the exhaust. With the iron cylinder you could open the exhaust port and get it to 192 or so. What pipe is it and what rpm range? Yeah, not really knowing what I am doing myself, I am using Johns #'s from early in this thread. You think it would be ok to take it to 192 with this pipe? The pipe is a Technigas that I have been unable to identify. I can tell you that it is massive compared to the Next-R I have, but other than that its a mystery to me. The stinger ID is identical to the one on the Next-R.
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Post by 2TDave on Oct 23, 2014 6:01:42 GMT -5
Looks like the RS pipe. I think your 130/190 is fine. John mentioned low 190's on my 70 build with the C16. It's a lot easier to raise the duration later than decrease it.
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Post by oldgeek on Oct 23, 2014 14:50:55 GMT -5
I love my drill press! It looks like it is spinning fast in the picture, but it is only doing 480 RPM. This head is a cheap 50cc squish style that I am opening up for use with the 70cc streetrace cylinder.
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Post by jareeb on Oct 23, 2014 15:21:37 GMT -5
im gona have to save my 50 head
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Post by 2TDave on Oct 23, 2014 15:40:52 GMT -5
I need a bigger garage and more toys like that.
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Post by oldgeek on Nov 3, 2014 22:20:13 GMT -5
I have been thinking about what may have caused my problem with this motor this time. It happened shortly after changing to a different pipe. When I installed the new pipe, I had just repacked the silencer. This time, I decided to line it first with regular steel wool, then packing. I wonder if the silencer got hot enough to melt the steel wool into a small ball that then got sucked into the cylinder? Its hard to see in the picture, but it looks like something small is imbedded in the piston.
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Post by oldgeek on Nov 14, 2014 23:36:25 GMT -5
I have finished the filling, and trenching of the cases I wanted to do this time around. I also raised the roof of the exhaust port on the cylinder by <1mm. I slapped it together and set up the degreee wheel for a final check of the durations. With 1.6 mm of base gasket, and the cylinder torqued to 10 ft lb's I have 131 on the transfers and 194 on the exhaust. The bottom of the transfers are flush with the top of the piston at BDC as has been suggested to do by 190mech. Squish is 1.1mm. I am hoping final torque will bring the transfers to 130 which is the maximum suggested, the exhaust to 193 and the squish to <1mm.
I have a couple ways to obtain the 1.6 mm base gasket that I need, and I was wondering what would work best.
1) I have some thick 1.75 mm gasket material from work that is used to seal compressor heads, its pretty tough stuff,that would compress a good bit I think. 2) I could use 2, .3mm metal gaskets sandwiched between 2, .5mm paper gaskets. 3) or 1, .2mm metal gasket sandwiched between 2, .7mm paper gaskets.
Also should sealer be used on the base gaskets, or possibly just copper spray?
I hope the pipe I am using will be a good match to the durations I end up with!
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Post by 190mech on Nov 15, 2014 5:07:47 GMT -5
Keep the paper gasket thickness to a minimum,thicker stuff settles and head torque is lost..The ideal setup would be an aluminum base shim with sealer on both sides...
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Post by oldgeek on Nov 15, 2014 9:07:55 GMT -5
Keep the paper gasket thickness to a minimum,thicker stuff settles and head torque is lost..The ideal setup would be an aluminum base shim with sealer on both sides... Thanks! Ill see what what thickness aluminum I have around here, might be time to fab up a spacer. Alternately, would it be ok to use stacked metal gaskets to get the desired thickness?
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Post by 90GTVert on Nov 15, 2014 15:34:21 GMT -5
Should be alright with metal gaskets and sealer. I like using a spacer and sealant the best as well. Using a paper gasket now with my 103 setups and I always have to re-torque after it settles. Plus, sealant coated gaskets get ruined on disassembly but with metal it only requires a cleanup.
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Post by oldgeek on Nov 16, 2014 20:30:52 GMT -5
The thinnest aluminum I had on hand was 3mm. I found some .75mm at home depot so I bought that. I figured 2 of the .75 mm would = the 1.5mm I need. I traced out a couple gaskets with a sharpie on the .75 aluminum sheet and started cutting them out. I used a big pair of sizzors to cut them around the outside, but that would not work for the center of them. I decided to use my dremel cut off wheel to remove some of the center, but I quickly found out that was a very good way to cut your knuckle damm near to the bone! I decided there was a better way to do it, and set out to the pawn shops to hopefully find a scroll saw. To my amazement, I found an old cast iron base 16" craftsman for the low price of.....$19.00?! No variable speed, no blade, and the yellow plastic child lock thing that has to be in the switch for it to turn on was missing. I stopped at sears on the way to the warehouse and found some blades to fit it for $10.00 I got the saw running, and cut the gaskets out pretty quickly. With some practice you could cut them out perfectly, and not have to use a dremel to finish them up like I did. Now I just have to clean everything up, and I am ready for assembly.
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Post by 90GTVert on Nov 17, 2014 9:46:10 GMT -5
Nice work on the spacers!
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