How much horsepower is loss with shim under bucket vs heavy duty shim on top springs?

 

I believe the answer is "a negligable amount"...its peace of mind that's the substantial quantifier that you gain with shim under bucket when you start pushing upwards of 10 grand and risk floating the valves. I know this doesn't answer your question so I'll shut up now....[img]i/expressions/face-icon-small-blush.gif[/img]

 

Hey jiminok
its an open forum please always never be afraid to put in some input!

 

I appreciate the vote there, ERBEDS...its been awhile since I posted anything. Feels kinda wierd...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Was thinking the same thing. . . wow. . . what. . . years???

Good to see you, what's been up with you? (Sorry to hijack the thread)

Back to the thread. . .

I'ld wonder how much is lost with new cam springs vs. older cam springs. Those things are stiff and when they are new they are hard to push down. . . I'm due for a change-out of cam springs - 2-years on this set so, very interested to see how they have held up.

I ran two sets of Pami springs and didn't get good life out of them so, this time I'm running Ron Wood springs. . . we'll see how they look.

 

I don't get to ride too much or at least haven't over the past couple years--job change, moved a couple times, marriage, the works--but now that I'm finally grounded and I've got an interested riding partner I'm kinda wanting to get back into the saddle and in attempt to be a vigilant doitmyselfer, answers to questions like, "what's the life expectancy of valve springs", spark my interest...

Stock?
Modified?

Just adjusted my mostly stock '03 valve clearance--intake was at .0015", exhaust was good.
December '03 I made a trip to see the good ole boys in Kentucky and haven't been under the hood since...maybe 75-100 hours on the build...

I don't plan on attempting to keep up with the pacesetters, don't get me wrong, mainly just want a good looking ride like MrMeaner has--PROPS--and to not get injured and have a good time. Not to much to ask for a guy turning 40 next Monday! Most bang for the buck is what most of us are interested in....eventually! LOL

 

My thoughts on valve springs - they are the weakest part of a high performance motor.

The word heavy duty is just a sales tool. Yes you need them to achieve high rpm's, but they should be called race springs instead. Heavy duty makes you think that they will last longer than stock.

To go over 8k with no valve float you need stiffer spings. To get stiffer springs they need to be a dual springs. With dual springs comes two springs with two different harmonic forces.
These forces together generate multiple patterns of high freqencies. These frequencies spike the natural frequency of each spring and in turn cause micro cracks in the metal of spring.

With high lift cams we now add acceleration spikes to the equation and cause the springs to more g-forces.

High rpm's, high lift and dual springs all add to the equation that makes springs become the weak link.

The cure - invent a single spring that changes frequencies that do not cause the spring to fracture its self. Must be able to reach high rpm's and high ramp forces of big cams.

For now track the useage of your quad :
Race Motor - Once a year
HP Trail - Every 2 years
Moderate use HP Trail - every 3 years