Originally Posted by jeffstevens763@g
it would be interesting to see what difference it actually makes on the rise and fall on a sib engine height?
Well in my humble opinion....lots. Plus or minus as little as 10mm either side of optimum can have a dramatic effect on performance and/or splashing.
Most boat/engine manuals usually state AV plate within 0 to 50mm below keel. With on water testing we usually end up with AV plate about 10mm lower than keel. This gives us good performance, no splashing, but occasional ventilation out of tight turns. It's always a compromise but this set up suits us for slight swell and chop....our usual conditions.
Obviously trim is also critical....we set this up so AV plate is as close to horizontal when on the plane.
Well worth a bit of effort/faffing to get this right as the performance gains can be surprising.
As Fenlander quite rightly mentions the Aerotec does seem to have its own unique set of splashing problems, although never had this come back into boat! Luckily, we seem to have virtually eliminated any excessive splashing with both our Suzuki and Tohatsu motors. I think the Suzuki lower leg profile with large AV plate, upper deflector plate and pointed leading edge really help negate the problems caused by the Aerotec deep V transom.