Stock type 3 engine CR - do i have the numbers wrong?

[Marc]

If you can get Bugpack cams, I'd use the 4061 with stock 1.1:1 rockers. Engle W-110 would work OK too.
These cams, like most "stock-rocker" cams were designed for 1.1:1 rockers, and although they will work with 1.25:1 there's not much safety margin left in the ramp rates - I wouldn't do it on a street engine.
Stock valve springs are borderline with these grinds even at 1.1:1. I've got one 1679 that's been together for many years running the Bugpack 4061, assembled with new stock springs shimmed .060", stock rockers, adjusters, and pushrods. With 1.25:1 you'd need HD singles, and it'd be wise to upgrade the pushrods too...not worth the cost IMO for an engine that'll probably never see more than ~5000 rpm.

[Ravivos]

Hi Marc,
Thanks for the answers...
i am still considering how to go with the build and did a bit more reading trying to "see the bigger picture" for the proper component selection.
would like to pick your brain a bit, if its o.k with you...
how about using a 85.5 (or 88 slip in) B pistons on a 74mm crank ? wouldn't that eliminate the need for the thicker shims under the cylinder thus wont present a problem with the rocker geometry/exhaust/tin ?

Am i been to picky on how to build the engine? guess I'm looking for a direction...
its just that if i go and take the engine out and rebuild it, i want to make sure i get the maximum performance available without going into too much machining/modification/headaches ...

[Marc]

"B" pistons have a compression height which is theoretically correct for a stroke of ~80.2mm - generally speaking, they're used for strokes of 78mm and above. With a 74mm stroke, there'd be ~3.1mm "excess" deck height (around .185" or so total) unless the cylinders were shortened or longer rods were used...still not a simple plan.