novadude wrote:Can someone explain to me why you'd chose one or the other? I know most OEM SBCs (with few exceptions), had press fit pins, but I've noticed that even "budget" pistons (like KB hypers, etc) seem to be coming with spiroloc grooves these days. Any reason to choose floating over press-fit (or vice-versa) when building a mild 300-400 hp basic street 350 Chevy?
Hi "nova", the "positive" sides to "floaters" far outweigh's the "negatives"!
Just a couple, you can assemble and disassemble the pistons/rods even with the 4 lock ring setup (if necessary, carefully) for any add'l machining after the initial mock-up, flycutting the pistons for instance!
On initial mock-up you can hold the pins in position with 2 strips of simple masking tape in place of the permanent locks. You don't need any "special" equipment, pin-press/rod heater, during final assembling!
As mentioned above, you get one pressed on "backwards" this COULD really open the proverbial "can of worms". It takes some special attention to R and R a pressed pin deal without destroying a piston?? To add also, I've never "lost" a lock ring, but I will say some years ago, when most locks were the "Waldes" type (these are the one R and R'd with special pliers) occasionally a lock would find it's way out. But it usually could be traced back to improperly installing the "Waldes" ring. One side was "flat" and one side was "rolled" on this style lock, the "rolled" side had to go against the wrist pin, the "flat" to the piston groove! Many had gotten installed incorrectly in the arena!
Thanks, Gary in N.Y.
P.S. One add'l feature is you "free-up" some add'l internal frictional HP, may be a small number, but it is on the "plus" side. This reason by itself is a "major" plus over here!
Jan. 2016 - New York Street Ride 7.56 @ 190 @ 3800#