Josh Shoemaker
Member
the 5/16" feed from the pump to the carb was an "industry standard" back at that point in time. All carbs that were oem were set up for a 5/16" tube fuel feed. As far as why the s80 tanks are plumbed in 1/4", I have a theory that some real oldtimers have related to me is essentially correct:
those tanks were actually originally designed for use in some agricultural products (both a hay bailer and a small combine) that used the 152 engine also. There were many of those motors used in ag products and as stationary power units, also in some tractors. In other words, they already were production items so that the s80 overall vehicle design used as many existing components as possible to both reduce development time and cost. That is pretty obvious when ya see how crude the earliest s80 is compared to say a late '62 or '63 version that quickly "evolved" as both sales and production ramped up. Distinct differences between the two units.
Unfortunately...the one person who could answer this question definitively, passed away more than a year ago, the guy who is considered the primary designer of these rigs, Ted Ornas. We were honored to have Ted's son attend the 2009 Sierra Fall Rallye and present an perpetual award in Ted's memory.
Maybe Mike Ismail (IH only) can shed more light on this, he and his family were fortunate to be able to spend time with mr. Ornas a few year's ago after attending the nationals in springfield, oh. Mike has the earliest known existing Scout 80 (a superb resto!) and he was able to have mr. Ornas actually inspect it!
Looks like we're still having server issues, I'll edit this post later with a pic of the Ornas family award!
So it is just a standard but dosen't really serve a purpose. Ok I see now. I am going to run 5/16 from the pump to carb. 1/4 from the pump to the tank. Along with an inline filter somewhere in there.

