Ok the answer is terrible holeshot if you can call it a hole shot.
The slippage when pulling away is a total disaster and the boat hardly seems to move just brings up the nose very high.
Then once its on the plane its like a turbo boost hitting you then takes off.
With the gearbox fully under water is what i tried.
The cav plate about 2 inch above the very bottom of the boat,so all the bullet and more is under water..
Top speed with a 13 3/4 x 23 omc silver streak semi-cleaver is just 1.5 mph better than a 13x19 omc sst prop at 39.8mph.
(omc SST 13x19 stainless = 38.3
But the 13x19 pulls away instantly.
With the semi-cleaver i got to 5400rpms max, with the 19 i ony got to 5200 max but less slippage.
now i also tried a 12 3/4x23 alloy prop and that just dont like the cav plate being 2 inches up at all.
This prop slipped and cavitated terrible and just wasnt much cop to be honest.
i got 5400 rpms and just 36mph from that one
I can get 34.9 with 2 people on just a 13 1/4 x 15 alloy but with terrible steering reactions from it.
So it looks like i need a jack plate for the semi-cleaver or use the omc sst (original race prop from 1972) for a good all round prop.
Once i find a cheap jack plate i can then see what results the semi-cleaver will do on this boat.
Now before anyone says these are slow speeds, i must point out that all these tests were carried out on a
13ft orkney dory thats only realy designed for a maximum of 30mph !!!!
so im not doing to bad with a 1995 evinrude 60hp triple on it.
And i must say the rooster tail you can get with the cleaver is brilliant
but 1mph slower than leveling the engine off ha ha
I think they hate me on the upper thames...