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Joined: 8/18/2002 From: NearBy,
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Bill I picked up a low milage 1.20 today real reasonable... The box says FA120S... Has a G stampted on the engine lug.. Cast intake pipe, curved exaust pipe and a stack on it. The crankcase vent is out the back cover.. Not sure I like that.. From you pictures in previous posts it appears to be the AAC version... Question, is there any way to tell if this is indeed the "S" version by looking at the engine ?.. If I understand what you have said correctly the S version is hotter version of the 1.20 ?... Thanks IC
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Inside every older person is a younger person wondering what the hell happened
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Joined: 11/10/2002 From: Mary Esther, Florida, FL, USA Status: offline
IC:
Positive identification of the various big block engines can be a little difficult, but I think what you got is the latest version of the FA-120. If it's a white box it's almost definite.
ABC/AAC - in the first picture you can see the cylinder fins extending over the cam box, this is the ABC cylinder. Contrast that to the second picture with the fins much smaller. The smaller fins are the AAC type. Contrary to what you might think, the smaller fins give no loss of cooling since the brass/aluminum joint was less efficient, the ABC needed the larger fins, the AAC does not. The AAC therefore is lighter not only by eliminating the cast in brass sleeve, but less metal is needed for the fins.
In the first picture note the push rod tubes going all the way down to the cam box, this is the "Low cam" engine. In all the others, if you look closely, the "Lump" in the rubber is well above the cam box, this is the sign of the "High" cam. Fifth picture shows it clearly.
The third picture shows what you probably got. The early hot FA-120S still had the cast sign "FA-120" on the right side, the later ones have the sticker that says only "120S" there. This was probably an economy measure for Saito, using the same casting for all the big block engines and just putting the right sticker on each size. Internal machining is different, but the outside is the same.
All the parts of the original FA-120S and the later version will interchange except the cylinder and intake pipe. Since the original version had only the o-ring seal for the intake pipe it also had a metal mounting bracket added to support the carb.
Hope I've covered your questions, if not let me know.
Bill.
Pictures: 1) FA-120 ABC, low cam. 2) FA-120S AAC, high cam, pipe intake, hot version. 3) FA-120S AAC, high cam, cast intake, current version. 4) FA-120S AAC, hot version, different view. 5) FA-120S AAC, hot version,showing cam box.
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Seems fine... We think it the carb, so were gunna try another one from a 65 that idles as slow as any Harley. LOL That will be a good starting reference... Here's the rest of the plane. I've been flying it for about 2 years, and Im sad they discontinued them... I would buy another, and this one is really gettin used up. Lots of hours on the poor thing...
Posts: 2409
Joined: 8/18/2002 From: NearBy,
AZ, USA Status: offline
Bill In reply to post 255 It appears to be picture #3... Based primarily on the intake manifold with the 90 degree bend in it... It did come however in a gold and black box.. Dang, Thought I had a hot one .. Does the back cover vent cause lubrication problems with the cam etc ?.. Also there appears to be some carb parts in the box... A spray bar, HS needle etc which appear to have been repalced... Was there an upgrade to the carb on these... Haven't fired it up yet but it appears to have good compression and all...
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Inside every older person is a younger person wondering what the hell happened