Breaking in valve springs


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By Ted - 15 Years Ago

Here’s a tidbit from the Comp Cams website regarding breaking in valve springs.  Pretty well mirrors some of the documention I’ve received from the other manufacturers.  I’ll suspect that this is some of the trickle down that occurs from testing in the Nascar arena.

 

Breaking In a Spring

1. It is important for new springs to take a heat-set. Never abuse or run the engine at high rpm when the springs are new. Upon initial start-up, limit rpm to 1500 to 2000 until the temperature has reached operating levels. Shut off the engine and allow the springs to cool to room temperature. This usually will eliminate early breakage and prolong spring life. After the spring has been “broken-in”, it is common for it to lose a slight amount of pressure. Once this initial pressure loss occurs, the spring pressure should remain constant unless the engine is abused and the spring becomes overstressed. Then the springs must either be replaced or shimmed to the correct pressure.

And here’s the link.

http://www.cpgnation.com/forum/truth-about-valve-springs-2631.html

By crenwelge - 15 Years Ago
This is the kind of stuff the old timers taught me 50 years ago. Its a good feeling to see it in print 50 years later and discover that for the most part, the old timers understood a lot in a world that wasn't high tech. Now I'm one of the old timers, but I think I'm lost in the world of high tech.
By DANIEL TINDER - 15 Years Ago
Thanks Ted. Turns out, I already had that bulletin, and when I finally found my hard copy, the section on spring break-in had been HIGHLIGHTED! (color me chagrined).



As a side note, while reviewing an old car-mag article re: cam break-in, they suggested that RPMs should not remain constant during the 20 min. burnishing period, because varying speed would distribute the splash-oil over more of the cam surface. Since this idea has not been included with all the Y-Block-specific break-in instructions I have come across (I thought cam oiling was more dependent on rod side-clearance spray?), I wonder if this tidbit (like most everything else found in current rod mags) is largely scrub-related?
By DANIEL TINDER - 15 Years Ago
P.S. The Comp Cam bulletin also recommends using their assembly spray, and warns about cleaning them with solvents. If they end up sitting around a long time gathering dust, would washing in soapy water and then dipping in engine oil suffice? I wonder what is so special about their spray?
By Ted - 15 Years Ago

Ditto on the varying of the rpms during the initial breakin.  This allows oil to get thrown around to different areas that would otherwise not get oil if the rpms were held constant.  Varying the rpms also allows what little heat loading that is being applied to also vary.

 

I’ll rinse the valve springs in the parts cleaner before assembly as I’m not a soapy water fan for engine parts cleaning as there are some coatings or preservatives that are not easily broken down with a water solution.  I have the same concerns as yourself in that I don’t want any dust or unknown rust preventatives in the engine.  As far as the spray being special, I’ll suspect that it’s just a low viscosity lubricant.  It’s important for the valve springs to be wet with something (oil is preferred) so they don’t initially overheat.

By DANIEL TINDER - 15 Years Ago
Ted (1/17/2010) I’ll rinse the valve springs in the parts cleaner


Now I'm in a bit of a quandary (Comp Cams solvent warning). For those of us that don't have a pro shop/parts cleaner facility (I usually resort to Simple Green, kerosene, or lacquer thinner, in that order), can you recommend something more specific that would qualify as safe?
By Ted - 15 Years Ago
DANIEL TINDER (1/18/2010)
Now I'm in a bit of a quandary (Comp Cams solvent warning). For those of us that don't have a pro shop/parts cleaner facility (I usually resort to Simple Green, kerosene, or lacquer thinner, in that order), can you recommend something more specific that would qualify as safe?
Let’s not make this overly complicated.  Just air blow the parts dry after cleaning and reinstall. Then just coat all parts with some kind of oil before actually firing the engine for the first time.  What the parts are actually cleaned with is only a minor consideration as long as they have been thoroughly dried before being  reinstalled.  This aint rocket science as in this instance, low tech is a good thing.
By mctim64 - 15 Years Ago
Good info here!  That is what I like about this site. Smile