To bring anyone up to date on the last of the communicas with Autoprop.
I emailed them at the end of last month; April 30th, a couple of answers to what I hoped would be the final questions they wanted to know about. I never received a reply. So I emailed a followup May 14th and hadn't heard again for two days. Finally today I called them. The individual I had been talking to was in New Zealand
. I asked if he received his email there and they said yes. They gave me to another individual that I spoke with on the phone
by the name of David.
He was nice and informative and this is some more of what I gathered from him.
He indicated that the correct prop for that engine transmission
was a 22" prop. Granted that is larger than I have larger than the apperature would handle. I informed him that the prop tip came to 1 1/2" from the top of the hull
with the prop I had. He indicated that that was within tolerances of Autoprop. He did indicate that 10% of the diameter would be better in which I concured. He also said that they could re - cup the blades and that might bring the rpms up to say 1500 or so for hull speed
. My main concern now is running the engine always below 1500 knowing that diesels don't love to be continously run at 40-50% of the their rpm
range for any time.
He further indicated the with Autoprops they need the diameter and that if the diameter is too small for the engine size he said something to the effect; and I hope I'm getting this correct, the prop will collapse and not provide any thrust in adverse conditions. That now to is going to be of concern to me as if we have the prop recupped then I would be going to be more likely to have the blades go flat than if we had one of an inch less in diameter.
He said he would rework the numbers and get back with me in hopefully the next day, definitely by the end of the week. He also said that with my setup we may not be able to make it work and would need to return the prop and refund our money
. I'm still hoping for a working Autoprop. Don't know what I'll get if we need to begin looking again.
My original prop was 20" x 10". Right now I give it about a 50-50 chance of us staying with this prop. I like it, I like the no cavitation, I don't like the control of speed. What I believe is that with my engine and boat and the correct prop of 20" x 10" the Autoprop wants to act more like a 21" x 21" prop and we'll see what they say about fixing that. The 20"x 10" is rather flat to begin with and it just may be that boats that have squarer props would be better served with the Autoprop and not boats that have fixed aperatures and larger engines with a flatter pitch
. Just my 2 cents.
Comments are appreciated and I'll keep this board informed of the results till the end.