Harley engine people (S&S Super Stock Case )

[afterburn 549]

A VERGIN S&S EVO Super Stock Case Fell into my lap !
So, I guess I need to do something about it.
But what?
What stroke and bore is best for this ?
I want it to be around 10.5 CR.
Most of these, back in the day, were built to 96 inches>?
Maybe?
My thought is as over SQ as it can get.
As big as it can be made.
What do you Harley people think?
Thanx

[Jeff Higgins]

3 5/8" bore with a 4 5/8" stroke for 96 cubic inches is the "classic" build on these, but then again, you know that. Would these cases need to be bored to accept 3 5/8" cylinders? Not that boring them is a big deal.

3 5/8" is, I believe, the limit on bore size due to the base stud spacing. If you use those and do not stroke it, the best you will get is still a massively under square motor at 3 5/8" x 4 1/4". So, in light of the fact that you will never get one of these motors even close to square, much less over square, I would just go with the 96" big bore stroker. It's a proven setup, parts are available, they have a reasonable service life, etc. Lots going for that combination.

[afterburn 549]

Thanx Jeff,
Maybe that explains this falling out of the sky, almost?
No one wants little engines anymore.
For a certainty, I hate under Sq.
I will guess the cylinder studs can't be moved out for a larger bore?
Too bad, as this thing is factory fresh, new, never a cam bearing even installed.

[Jeff Higgins]

I think once you try to go big enough to require moving the cylinder studs, the lifter blocks are in the way as well. From what I know about Evo motors, 3 5/8" is the limit on stock case configurations. I know S&S makes a set of cases that can go up a 4 1/2" bore, but I bet you'll never have a set of those fall into your lap.

I don't like under square either. It's our lot in life as Harley riders, though, especially the older ones. A buddy has a '76 Sporty like mine that he has installed a set of 4 5/8" stroker wheels. Talk about under square - 3 3/16" (80.96 mm) bores with a 4 5/8" (117.475 mm) stroke, which nets him 74 cubic inches (1,200 cc's). By way of comparison, Harley used a bore and stroke of 3.5" (88.9 mm) x 3.811" (96.8 mm) for 74 ci (1,200 cc's) on the Evo Sportster, so at least they were trying.

I remember when the TC88 first came out, and the way Harley touted its bore and stroke dimensions of 3 3/4" and 4" as being some kind of a modern breakthrough. Far, far better than the 80 ci Evo with its 3 1/2 bore and 4 1/4" stroke. Less vibration, less wear and tear, yada yada yada. Maybe. They offered 3 7/8" big bore kits, darn near making them "square" while increasing displacement to 95 ci.

Funny, though, their first bump in displacement went to 96 ci, because - wait for it - they chose to increase stroke rather than bore. They went to 4 3/8" on the stroke, even longer than the Evo. After all their b.s about the advantages of the shorter stroke. Why? So they could continue to sell their 3 7/8" big bore kits to bring those 96 inch motors up to 103 ci.

Anyway, back to that stroker Ironhead. Less power than the same displacement Evo, by far, with a good deal more vibration. It's really rather unpleasant to ride. It just wants to shake itself to pieces and doesn't reward with any kind of real power to make up for its unpleasant traits. Granted, the long stroke isn't the only thing contributing to this, but I've ridden plenty of Evo Sporties with far more power from the same displacement that are much more pleasant to ride, while not tearing themselves up in the process. So, yeah, give me oversquare anytime (my 900 cc Ducati is 92 mm x 68 mm), but I'm afraid "we can't get there from here" on our old Harleys.

[afterburn 549]

I appreciate the info, Jeff.
Thanx.
Under Sq is against my religion.
Way under Sq is some sort of a priori blasphemy.
So maybe I will just sell this case as new as it is , and as old as it is.