Measuring installed spring height, surely there is a better way.


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By 46yblock - 17 Years Ago
I have finished the installed spring height measurements, using a telescoping gauge, also known as a snap gauge.  Did each measurement four times and took an average.  Working with the two piece keepers plus getting the gauge just right is something else.  Surely there is a better way.  If roller rockers, aluminum 4v intakes, aluminum timing covers, and maybe heads can be produced, one of you guys needs to make a neat micrometer gauge like the SBC guys have to use. 

What are some common variances in final adjusted spring heights.  Given shims only come in .060 and .030, exact final figures seem difficult.  I did see that JM has a keeper that is +.050, so that would help on 4 of the springs, but dont know if it will fit stock springs.  Tried calling him this PM but he was out.

Mike   

By Ted - 17 Years Ago
Keeping valve spring heights within 0.010” of spec is typically the normal variance.  If using the +0.050” or -0.050” keepers or valve locks, it’s generally a good idea to use them throughout or in full sets so the next person working on the heads isn’t caught unawares.  That next person could very well be yourself again.  These offset keepers are available either from the various camshaft manufacturers or from your local machine shop as they’ve been around for many years.  Another option is to mill the seat pad slightly and then use the thicker shims but I’ve been able to purchase shims in 0.010” and 0.015” thicknesses depending upon the I.D. and O.D. I’m dealing with.
By DANIEL TINDER - 17 Years Ago
Mike,



How about using a weak/narrow spring to keep the parts tight/square while measuring installed height?

P.S. 1.50"OD X 1.031"ID seat shims are available in .015" from Goodson.



Ted,



While OEM type two-piece "rotator" retainers may even out seat wear and clean off carbon deposits, I wonder how useful they really are when using hard seats/stainless valves?








By DANIEL TINDER - 17 Years Ago
Mike,



I should mention minimum order from Goodson is box of 50. As I already have the .015"s, no need both of us to spend extra money. Will gladly trade for some .030"s, and I might even need some .060"s as I am having all my spring seats ground equidistant.
By 46yblock - 17 Years Ago
DANIEL TINDER (10/3/2008)
Mike,

I should mention minimum order from Goodson is box of 50. As I already have the .015"s, no need both of us to spend extra money. Will gladly trade for some .030"s, and I might even need some .060"s as I am having all my spring seats ground equidistant.

Daniel,  that sounds like a winner.  There are 28 .030s here and not sure how many 60's.  I'll go over my figures and see how many .015s would work.  At an installed height of 1.725 the stock springs I have read 90 lbs. so that is what I will work with.  My heads should have a similar treatment as yours, but it is too costly at this time.

Ted, thanks for the info.  Splitting up stock and offset keepers was a question.  Good point.  Things can get confusing enough.

Mike

By 46yblock - 17 Years Ago
Yeah, with the use of .015 shims, heights tighten up a bunch.  They will be within .005 inch.  6 will do it.

Mike

By 46yblock - 17 Years Ago
After looking over the various installed spring heights for the umpteenth time, I've decided they arent good, meaning a WIDE range from valve to valve.  This goes back to the terrible job done to me by a "builder" in Kansas.  He installed 16 new hardened seats, but must have had a trainee on the job.  7 seats range from 1.800 to a tall 1.840.  The other nine are roughly 1.780 to 1.790.  I am going to take the heads back to the shop and see if they can reinstall seats for the 7. 

Hoosier Hurricane thankfully started me down this path with the heads when he advised to mill their intake sides rather than the manifold.  I had planned on bolting them up to the new block, thinking that since they only had a couple thousand miles since their last rework, they would be ready to go, not knowing how badly they were messed up in KS, and also not knowing that my trusted mechanic Bill had given way too little spring pressure.  For example the 1.840 spring had one .060 shim, which would have put it at stock spring height and approx. 65 lbs, with a 270 degree .460 lift cam.  No wonder there were carbon deposits on the back side of the intakes.

Patience, Patience.

Mike

By Ted - 17 Years Ago
DANIEL TINDER (10/3/2008)
Ted,  While OEM type two-piece "rotator" retainers may even out seat wear and clean off carbon deposits, I wonder how useful they really are when using hard seats/stainless valves?

My own preference is to get rid of the two piece retainers whenever possible and replace them with a single piece retainer.  Especially where there is a planned increase in valve spring pressures.  I’ve experienced no long term detriments to doing this and after seeing a number of two piece retainers failing on the outer portion simply reaffirms my thoughts on using the single piece retainers..  My own ’55 Customline with the 272 has had the single piece retainers with the hardened exhaust seats for over 100K miles and is still going strong.