I went with my Dad last night to tune in his new engine and I am not really sure how fast it is but it felt great. It is a 83 230 Scorpion with a new 406 Edelbrock headed balanced Small Block Chevy with GLM aluminum exhaust manifolds. It has a 14.25 x 21 prop and wide open and trimed up it would run 5300 RPMs. It felt great but my friend claimed there was no way that that boat turned that hard without a high slip factor. We did it for a solid 5 min. so I know the prop hub and coulped were not slipping. What is your input ?

You need speed to calculate slip exactly, but at 60 mph your slip is 15 and at 63 slip is10%. 5300 rpm 1.50 ratio 21 inch pitch.
Sounds pretty good. If you were going 55 that would be 21%. not so good.
Jim

there are several prop slip calculators on the web that will help.

We used a GPS yesterday and at 5200 RPMs it runs 54 mph so by the web site you recomended with a 21p x14.25 prop and a 1.5 drive it has a 22% slip ratio. Where should I go from here? A larger dia. prop or more blades ?

I would recommend a 23 pitch. I changed mine from 21's to 23's and it works much better. This may not be the case for all as there is another thread concerning this, and others have complained that their engines won't turn 23's but I have no issues with this. My boat skoots along at an easy 54-55mph.
Good luck on your experiment.

ve3lt is SS 3 blade or 4 and how hard r u turning

I bought it on ebay last night .A friend of mine recomended it . Any thoughts ? What should I expect ?

no... ss is too rich for my blood this season. I have already gone through three pairs of aluminums...I know its my own fault for being stupid and going where I shouldn't, but at least I had the opportunity to play with pitches etc.
I have Quicksilver 23's in aluminum-3 blade. Lets hope I can keep turning them the rest of the season!
I run at about 4600 rpm.

I don't know how the other guy in this thread runs around 5500? That is so hard on a crankshaft!!! His engine will not last long doing that all the time. Apparently some chart on the internet call for 4600 to be the correct turning speed for CC Scorpion/Stinger 260's with 5.7's and I am only 100 or 200 rpms slower at times(depending on lake conditions)
I'm right in the ballpark now. My first props were 21's and I was also running in the mid 5000's but the 23's changed that. It still climbs out of the water very fast.

10-4 on that i'm pulling the 4 blade SS 23's off and throwing on 23 3 blade aluminum to see what they do. I'll lecha know, maybe the same as yours, who knows.