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ANATOMY of a SICK SAITO
PART TWO: Clean, Inspect, Re-assemble

      After a good cleaning and inspection, each part will be fitted in its proper place with Lubriplate.  The Lubriplate will protect the parts from scuffing during the first startup. After that, it will be up to the engine to provide the necessary lubrication.

      All the parts were chemically cleaned to remove the coating of rust and carbon, then they were brushed and washed with good old fashon soap & water. The parts were then inspected for fit & finish. If they passed the fit & finish, they were placed into the tumbler for final polishing for about 12 hours.  The tumbler will remove any and all micro particles left behind from the previous cleaning stages and put a bright finish on the parts.

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The crankcase was in exceptional condition and only required a good cleaning & polishing to remove the FOD. The bearing supports are perfect and all the threads are OK. The crankcase is DONE.

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The jug assembly & combustion chamber is in good condition and the valves, valve springs, and rockers are as good as new. The valves seal perfectly. The Jug is DONE.

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The camshaft housing cleaned up great and is ready, however the camshaft and lifters are in very bad condition with pitting and some gouging on the bearing surfaces. This is totally un-acceptable and the engine wouldn't run long before they completly wore out regardless of how much lubrication they would get. These bearing surfaces need to be smooth and flawless for proper seating.

HOUSTON, we may have a PROBLEM!

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The crankshaft has visual indications of extreme wear on the rod journal. THIS IS NOT GOOD. A Saito 100 crankshaft is about $100.00. About all I can do at this point is, mic the journal and rod to see exactly how much wear there is between them. The absolute MAXIMUM clearance is .0015", any more than that and it's trash. The rod would have to be replaced also...  There is a slim chance I can displace the bearing surface on the rod and salvage the entire assembly. But this is a 1 in 10 chance it'll work out properly.

Right now I'm waiting on the rod to complete the cleaning cycle before I can determine the fate of the crankshaft & rod assembly.

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It's now reckoning time... checking the rod to crankshaft journal fit.

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It's decision time! DO WE; 
                                         (A) Replace the Crankshaft & Rod?
                                          (B) Attempt to tighten up the tolerances on these parts?
                                          (C) Use it as it is, and take our chances?
                                          (D) Abort the Overhaul?

The decision was to move forward with a new crankshaft & rod. We'll be adding HP Stainless Steel bearings, and upgrading the ventilation system.

In essence, this Saito 100 will be one of 5 that I've "BLUE PRINTED" over the years. Blue Printing is a method by which every part in the engine is hand-fitted to precise tolerances. The fit is so precise that there's virtually no break-in time needed. Blue Printed engines generally yield 5 to 10% more horsepower to the crankshaft without any modifications.  

And the BLUE PRINTING begins!


The first item on the docket is the piston:
I will reduce the ring-land diameter by .004", add 2 each .0625" lubrication slots to the skirts, and deck the top .002". The piston skirt diameter will be sized exactly .0025" below the root mean cylinder diameter. Finally, the piston will be Molykote quenched and balanced.

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The Molykoting will be last as all the parts need to be done at the same time, and will have a thickness of about 1 micron.     

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To really optimize the additional breathing, 2 oneway valves can be added to provide Positive Crankcase Ventialtion (PCV). This will ensure fresh air goes in and violated air goes out. It can be routed to the intake manifold to re-cycle the vented air, it also keeps your airplane CLEAN!. This is very similar to Saito's twin cylinder configuration. Just this simple PCV can add as much as two tenths of a horsepower by reducing piston drag in the crankcase! It will also lower the crankcase temperature slightly.

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