OST-017: Ed Sullivan it ain't!

[oldeskewltoy]

OH... MY LORD..............

The parts delay, and machine work for this head culminated back in mid September, that was just before/as I began "OST-019". I chose not to run both threads @ the same time... AND I used OST-019 to re-familiarize myself with removing material from the chamber...

mind you nothing other then doing it gets you comfortable with removing MASS QUANTITIES of ALUMINUM from the combustion chambers of a $2500 head........ and hoping you don't fudge it up :eek:

But I move a bit too quickly over the machining details... so let me catch up. There is much required to do and check when preparing an O/S valve head that runs 300 duration 10+mm lift cams. Many here have checked valve to piston clearance when building their engines.... but how many of you had to check for valve to valve clearance??? Some of you know what I'm referring too, but the rest???

Valve to valve clearance is something that must be done on 40+ degree valve angle heads(Toyota 4 valve "G" heads) when using LONG duration high lift cams in conjunction with O/S valves. The camshafts are installed, and "timed" to each other. The camshafts are rotated slowly to make sure the intake valves don't hit the exhaust valves... and visa versa.


not the head I'm working on, but it shows potential for valve to valve contact

Once this is verified, final depths are determined by measuring the 1SZ buckets (the thickest set) and then calculating the depth to the camshafts base circle for that particular lobe. Times 16... then doing the math and "mixing" buckets and valves till all you have are a valve tip or 2 that gets "tipped". Now all the buckets, valves, and cams are set :eek:

So... with all the machining(over 12 hours @ Loynings :eek: ) now finished... I get out the burette.........



and measure the chambers.... #1 - 36.6, #2 - 36.5, #3 - 36.3, #4 - 36.6 if you remember a few chambers had seen some tool work by the previous porter, as well as a little bit from me... that explains the .3cc difference between the larger ones, and the smaller one

Once measured..... cutting begins... I begin on #4 chamber. I need to increase the chambers volume by 2.9cc or a little over 8%....

The top view is the chamber prior to resizing... you can see the Sharpie outline of the head gasket.....


another 3 panel

the middle panel shows the right hand side of the chamber roughed out, and in the bottom view, the chamber has been opened up 39.3cc, the last 2/10 of a cc I'll get while hand shaping, and polishing.



More to come.......