RE: Setting up an OS 1.60, cline, bisson pitts, 18x6w
Yes I believe STG is running that engine competitively so he's most certainly someone you should listen to.
I think he's spot on with the R's. I would expect even greater things at 8000 and some pattern guys are far lower than that.... it depends on how you're going to be driving the engine. Some use a 17x12, you can imagine how slow that is turning... we can get away with it be cause our planes weigh typically say 9.5 -10.5lbs. Very light compared to the average Imac type setup.
When it come to props i'm an APC man. I can't judge what changes different diameter/pitches are making if i'm jumping from one brand to another. Again Listen to what STG's having luck with.
Yes having the short pipe from the reg' to the carb is what it saying in the instructions, but it isn't alway the best for any and all carb's.
Try it and see. Again it's just fantasy to think you can fit a regulator to any engine and life is good. It just doen't work that way.
Some carb designs work better with reg's and others with pumps. Everyone that I know uses a pump, Perry, OS with that engine.
Just try using a longer pipe and moving the reg' around, see what happens. Very ofen nothing, allowing folks to mount them on the fire wall!