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Old 11-10-2019, 01:59 PM   #70
mrlaser
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Join Date: Sep 2019
Location: Savannah, Ga
Posts: 67
Default Re: 8BA compression issues

When the engine was rebuilt by the machine shop the cam,valves ,springs, and adjustable lifters were purchased by them. I do not know the source of the products. The intake valves are 4.829 in length. After lapping the valves and changing the valve springs to the shorter type shown in the Green Manual for the later rotator valves, the compression improved from the mid 40's to approximately 65 psi in all cylinders. With added oil there was an additional added 5 psi. At the time I did not check the height or set the proper spring pressure. I was aware of these steps but thought that ( as mentioned in Mike Bishop and Vern Tardel's book) this step was for a "performance engine". Being a novice at this, I incorrectly assumed that since my engine was to be a stock rebuild, I could simply put the springs in place without those two measurements. ( live and learn). I am now redoing the springs after making those calculations. I will report on the results when things are back together. The attached picture is of the intake valve and the initially installed taller spring on the left and on the right, the shorter spring used with the "51-'53 rotator valves which were in the engine originally. Thanks again for all your help.
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