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Post by stepthrutuner on Sept 21, 2009 21:13:21 GMT -5
This is very curious. Can you tell much difference in stiffness just by squeezing by hand?
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Post by stepthrutuner on Sept 21, 2009 21:33:56 GMT -5
Well the ramps are steeper so the valves are opening quicker. The old time/area thing, you know.... that should work well with your free flow mods. I think the stock springs are not a limiting factor anyway as long as the harmonics and pad wipe stuff jives out.
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Post by 90GTVert on Sept 21, 2009 22:21:32 GMT -5
The springs feel basically the same just squeezing them by hand. That's one of the first things I tried, just not too scientific. lol I don't think the springs are a problem either way, I kinda hate to throw in heavier valve train parts though. Hmmm. They shoulda included some real titanium retainers. That woulda been cool to have.
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Post by stepthrutuner on Sept 21, 2009 23:04:16 GMT -5
Are the cam assemblies much different in weight?
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Post by 90GTVert on Sept 21, 2009 23:46:32 GMT -5
Gimme a minute and I'll tell ya.
Edit: Stock : 264g NCY : 264.2g
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Post by 90GTVert on Sept 22, 2009 0:26:03 GMT -5
--------------Diameter-----Length----Weight Stock Outer :__22.10mm__33.45mm__15.4g NCY Outer :___22.20mm__35.53mm__16.5g Stock Inner :__16.00mm__30.09mm__6.95g NCY Inner :___16.01mm__31.90mm__7.2g I popped the springs outta the 72cc head that has very few miles on it, just to see the difference. 72cc Outer :___22.10mm__34.18mm__15.6g 72cc Inner :___16.06mm__31.84mm__7.2g
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Post by stepthrutuner on Sept 22, 2009 0:45:52 GMT -5
Well, you still can't beat free.
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Post by 90GTVert on Sept 22, 2009 7:28:14 GMT -5
I think I'm going to use the springs from the 72cc head, just because they've got less wear on 'em. I just don't wanna put in heavier valve springs, especially when they seem like they're just stock springs to me. Of course I can't really tell anything without a spring pressure tool. I could install a shim in each one to get just a slight bit more pressure, but I don't think it's necessary.
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Post by Enviromoto on Sept 22, 2009 8:34:35 GMT -5
Very Interesting. All of the parts I sent you Brent came direct from Scooterworks so this is the best the industry has to offer :/
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Post by 90GTVert on Sept 22, 2009 9:14:37 GMT -5
Kinda sad. Now, like I said, I have no way to measure spring pressure. A gauge costs about $70 to use in the vice. I'm not doing that for $25 springs. They may put out more pressure. I can't see how they are titanium though. I'm no metallurgist, but titanium springs should really weigh less not more. The goal is to drop the mass and inertia and decrease harmonics at higher RPM levels. 1g isn't much, but I just don't see the point of adding that weight when the cam has stock lift values, although it does seem to have a little steeper ramp rates, and I can't seem to tell a difference in stiffness. Once again, I'm no expert so I may be way off. I looked for a homemade spring pressure tester, but the homemade stuff wasn't even cheap to make. I thought I had an idea to get some sort of result of my own, but I was wrong. I welded a bolt through a piece of scrap steel. I thought I could put the spring over the bolt and use a nut and a washer along with a torque wrench to see how much force I needed to apply to get the spring to compress to a certain height. Obviously it wouldn't tell spring pressure, but I thought it should give an indication of which springs exerted the most force to resist tightening the nut down. No such luck. My torque wrench doesn't even go low enough to measure the torque applied. I could tighten any of the springs to coil bind by hand.
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Post by 2strokd on Sept 22, 2009 9:52:13 GMT -5
You are thinking to much, i got that illness too lol, but while we are on the subject, you could make the bolt you welded a slide and attach weight to the bottom. That would give you an idea, more weight= stiffer spring.?.
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Post by 90GTVert on Sept 22, 2009 10:04:46 GMT -5
I was thinking about that, but then I though I don't know if I care that much. Even if it provides slightly greater spring pressure, is it worth added weight for a cam that doesn't appear to be ultra-radical? Would the added spring pressure simply cost me power because it's not necessary? Will it be helpful if I really can get the revs up? Unfortunately, I'm not knowledgeable enough to decipher all of that info. I hate to be a plug n play parts swapper, but with cars you usually buy a cam and get the springs recommended by the manufacturer. When I buy a Comp Cam for instance, and they recommend or include certain springs, I don't need to figure it out. I might do the weight thing, not ure what I wanna do.
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Post by 2strokd on Sept 22, 2009 10:08:26 GMT -5
I hear ya, you already did more than i would have. Anybody ever float these little valves anyway?
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Post by 90GTVert on Sept 22, 2009 10:24:21 GMT -5
I dunno, I know Reg had hit around 11,000RPM and broke a ring. Didn't say anything about valve float, but who knows.
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Post by stepthrutuner on Sept 22, 2009 10:57:59 GMT -5
I think my ring broke at around 11,700 while going downhill. As far as I know the valves never floated. At one time (although it was a pretty dry, crisp day) I had mine pulling and revving out incredibly well. I looked at the plug and thought it looked too lean so i drilled the main a little bit more. After that I could never get that state of tune back again. Of course mine was still a 50.
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