Top end sugestion, valve springs and rpms

Message

peterock · #31 Post by **peterock** » Thu May 17, 2007 6:36 pm

I have faith it'll hold up and run strong. After all these are american made. Crower can do this same set-up with the Jap quads and they hold up.

cannondale27 · #32 Post by **cannondale27** » Thu May 17, 2007 11:28 pm

I hope so.

wayneschofield · #33 Post by **wayneschofield** » Sat May 19, 2007 6:28 pm

You're a very brave man I feel, a true 'pioneer'...

For what it's going to cost, why not run the head up on a 'spintron', so you can see if you're getting any float before you fit it in your motor? Float on a valve on it's own isn't going to cause any problems but if you fit it in a motor and the inlets and exhasts touch the piston, or each other, then you heading for a heap of broken parts and a big bill for sure......

Basically, the 'spintron' machine can spin a cam up to varying speeds and high-speed cameras and lasers 'look' at what is going on.

With double springs, the two spring rates should be set so that their 'natural' oscillating frequencies 'cancel' each other out to some extent, which is why we use them rather than a single spring of the same rate as the two combined.... so to get rid of one is perhaps not wise...

A 'Bee-Hive' or tapered spring has different frequencies along it's length so oscillations are very localised within the spring so as to effectively bring the total spring oscillation to nothing. This negates the need for multiple springs and allows a spring rate low enough to solely deal with the valve assembly inertia...

That's my two-penneth anyway, don't take offence please.....

peterock · #34 Post by **peterock** » Sat May 19, 2007 10:16 pm

You lost me with the spring talk Wayne and no offense taken.

On the other note, too late.

Tested on the dyno today and everything held together with great results. Made the 50hp clup with this set-up. Obviously we aren't going to tell everyone that this is the way to go until we put some hours on it. Try at your own risk that is for sure.

cannondale27 · #35 Post by **cannondale27** » Sun May 20, 2007 3:10 am

I looked into spintron testing a while back.They wanted $10,000 or some crazy thing for an analysis.Maybe just head would be cheaper.Figured a few motors could be built for that price.Didnt see anything unusual during the runs.But am concerned about harmonics also.Those vibrations in spring do accelerate spring wear but so far so good.10,500 limiter might be reason.

peterock · #36 Post by **peterock** » Fri May 25, 2007 1:58 am

Crower TI Ported Head test results coming soon............

http://www.cannondalecentral.com/forums/showthread.php?t=790

m_mcgranahan · #37 Post by **m_mcgranahan** » Mon Aug 04, 2008 4:13 am

Hey Peter,

How did this all turn out for you? Any more info?

Thanks,

God bless...

Mark

peterock · #38 Post by **peterock** » Mon Aug 04, 2008 2:48 pm

everything has been working good. Tried to get some dyno numbers for the head and cams together but the dyno wasn't working on the day I was there.

m_mcgranahan · #39 Post by **m_mcgranahan** » Mon Aug 04, 2008 4:12 pm

Hi Peter,

How is the power band on it?

God bless...

Mark

peterock · #40 Post by **peterock** » Mon Aug 04, 2008 4:21 pm

It feels good and seems like it pulls good all the way through without the heavy top end hit. Unfortunately no dyno chart for comparison yet though. Right now I have to work out an electrical issue as well as my stator bolts backed out and shorted out some stuff. As soon as we get these power commanders I should have a dyno chart for it.