Originally Posted by jeffstevens763@g
just out of interest willk does the 4/3 blade set up work a bit like a jet engine in so much as the 3 blade compresses the water from the 4 blade or vise versa might be a stupid question as i no nothing of inboard set ups.
I know almost nothing about props but no, that's not what they are doing (even if you substitute "directs" for "compresses"). The pair counter rotate and one is somewhat smaller than the other. This stops the boat heeling/tilting when underway and reduces propwalk at close quarters. The front four blader is the bigger and I suspect that it does the heavy lifting.
She came with a 24" Pitch 6 blade pair, based on her size. They were hopelessly under pitched and she came out of the hole like a rabbit but redlined at 37-38kts. We fitted 26" (as they had a pair) and those were similar but redlined at 39-40kts. We ordered the current set and she now has a very acceptable hole shot and can just about tip the redline when fully fuelled with a few PAX onboard. "Lightship" she still has to be watched at WOT as she'll stray into the red very easily at around 42kts.