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Tuesday, April 28, 2009

head swap

Lifting a head out. Made a fixture that holds the head at the correct angle.
Measuring a lifter all the way collapsed to see what the travel really is.
Measuring a lifter at full extension. The lifters have a range of .220. The preload is .050 less than full extension with the stems ground to .032 less than standard. These heads have been milled .040 and the difference after the Felpro gasket I guessed at .020. The rocker ratio is 1.6 so 1.6 x .020 is .032.
Working in the hole.
While the the intake was off it was a good time to thread a hole for the Inlet Air Temperature sensor. Forgot to do that before. The injector bungs are plugged while I'm still running the carburetor. Megasquirt injection is next.

Sunday, April 26, 2009

Seal installation

K line positive seal with protector sleeve on stem and install driver. Basically you just tap it down on the guide. Guide tops had been machined to .530" for positive seals previously. These were used as original equipment on some Harley motorcycles. The stems were lubed so no dry startup. I had already shimmed the spring pockets for 1.670" spring height.
Stock style Felpro umbrella seals on the exhaust valves. These will ride up on the stem and stay after startup.

Saturday, April 25, 2009

Valve seal selection

I had these seal types to select from. On the exhaust seals the stock type Felpro umbrella are the way to go. The intakes were a different deal. CompCams teflon and the Felpro positive might keep to much oil out of my new guides. After much reading I decided to use the steel shell K-Line KL1405 seals. They are supposed to meter some oil down the stem to lubricate the guides. Some things I read claimed that this is best for a "street" engine for longer guide life. Using K-Line guides and seals makes sense.

Friday, April 10, 2009

Valve stem height

I made a poor man's stem height gage for Oldsmobile heads. The spec is 1.220 + - .005 for the top of the stem above the valve cover rail.
Setting the gage at 1.220. The bolt has a bevel and lines up with the center of the stem. The bevel there because the valves are not perpendicular to the cover surface.
Stem grinding on the valve grinder
Gage in use. The Olds 455 does not have an adjustable valve train so this height has to be right.