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Post by 90GTVert on Sept 22, 2009 11:46:15 GMT -5
I tried hanging weights from springs anyway. I still think i'm gonna use the fresher stock springs from the 72cc head, but why not? Here's what I came up with real quick... I had a big pin lying around for connecting tow behind lawn equipment. It has a nice built in washer on the top and a handle to make this easier. It's got a hole in the bottle for a cotter pin or clip... or in this case a clothes hanger. I slid the valve springs up onto it and then put a large washer under the spring. I put that through a section of a loading ramp that has holes in it and is plenty beefy to support the weight I'm working with. Then I attached weights to the bottom via the clothes hanger through the pin. I'm too lazy to attempt to measure installed height of the valve springs and try to achieve that by the exact amount of weight, so I did something pretty basic. I started with a stock spring and attached 35lbs to it. I then measured the height of the spring. Then I replicated that height on the NCY spring. I only did the outer springs. The pin is too large for the inners. 72cc Outer : 3/4" @ 35lbs NCY Outer : 3/4" @ 40lbs So the NCY is delivering a little more spring pressure. Considering Reg can't seem to float valves at 11,700RPM (granted he probably didn't have quite the same ramp angles) and I would be amazed to see 10,000RPM I don't see these springs being worth the money unless you are getting crazy with the cam and/or RPM. The additional weight and pressure applied to the rockers and cam seems unnecessary at that rate as well.
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Post by stepthrutuner on Sept 22, 2009 14:23:53 GMT -5
Cool testing. In lbs./in.: 72cc --- 46.7 NCY ---- 53.3
Therefore the NCY is 14% stiffer.
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Post by 90GTVert on Sept 22, 2009 14:49:36 GMT -5
Screw it. I'm gonna stick the head back together with the NCY springs. I don't think it's gonna matter much either way, but Jeremy did send them to me for "R&D" so I feel like I should use them for him. If I still go 32MPH, I'm gonna blame these springs. lol
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Post by Enviromoto on Sept 22, 2009 14:50:49 GMT -5
For the record these springs are for the 150cc GY6 but I sent them to Brent to see if they would work on the 50cc. Looks like they are to heavy to work properly. I wonder what the 150cc springs are like?
My problem is that I stay so busy working on scooters, shipping parts, and building my own customs that I rarely have the time to sit down and R&D.
Thanks Brent.
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Post by 90GTVert on Sept 22, 2009 15:35:25 GMT -5
Sorry, I forgot to post that they were supposed to be for a 150cc GY6. If these are an upgrade for 150cc springs, I'd have to guess that 150cc springs are very similar to 50cc springs. You'll know for sure if they work on a 50cc at some point in the near future. I can tell you that they install on a 50cc OK.
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Post by stepthrutuner on Sept 22, 2009 16:09:41 GMT -5
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Post by 90GTVert on Sept 22, 2009 16:14:58 GMT -5
Ouch. I'm curious to see what this little slug can do, but not that curious. I woulda been done spending before now if the thing wasn't just so damn slow.
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Post by 90GTVert on Sept 22, 2009 20:48:34 GMT -5
I mocked the engine up tonight and used some modeling clay to check piston to valve clearance. I watched the new valve springs as I rotated the engine to make sure nothing looked suspicious. I used no base gasket and no head gasket. I planned to use the old ones for mock up, but I forgot and threw 'em out a few days ago. I got .15" and .14" of clearance according to the clay. A base gasket measures in at .02" and the head gasket should be .01" compressed. That gives me a minimum of .17". That's a lot more than I expected. There would certainly be room for some milling if I ever decided to do it.
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Post by stepthrutuner on Sept 22, 2009 21:11:11 GMT -5
It sounds to me like this is a non-interference engine. I.e. cam chain could break and valves and piston would be cool with each other. Whew.
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Post by 90GTVert on Sept 22, 2009 21:19:58 GMT -5
Safety first. I'll prob be slightly closer because I'm gonna try using RTV instead of a base gasket. That should be similar to milling off .010" and hopefully that will cease the constant oil leaks. I'm tempted to get it milled, but I figured with that .010" and the .5cc reduction in combustion chamber volume, I should be at least a step in the right direction.
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Post by 90GTVert on Sept 23, 2009 20:42:14 GMT -5
The engine is back together and in the scoot, but I still need to tie up some loose ends.
The new exhaust header fits, but it is pressing up against the frame. I'll have to take it back off and grind a little bit of the frame. Don't worry, it's non-essential. It's a flat section by the engine mount that is probably 2.5" wide or more and 1/8" thick roughly. I need to take out a section about 1.25" wide and 0.125-0.25" deep just enough to keep it from sawing my new pipe off. I'll also need to make brackets for the new muffler, it didn't come with any.
The headlight is wired up. That 2 terminal socket does still have three wires, but one is tucked in and not ran out to the plug. Just had to do some soldering.
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Post by Enviromoto on Sept 23, 2009 20:48:18 GMT -5
Hmmmm keep up the good work Brent.
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Post by stepthrutuner on Sept 23, 2009 22:07:33 GMT -5
Can't wait for you to light off this ground shaking beast. Think you can handle it? ;D
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Post by 90GTVert on Sept 23, 2009 22:12:10 GMT -5
lol I'm pretty sure I can handle 33MPH.
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Post by stepthrutuner on Sept 23, 2009 22:53:39 GMT -5
Don't forget the NOS sticker. That'd have to be good for at least 35.
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