Please Recommend-BEST IMPELLER PULLER
- Thread starter RWS
- Start date
That's funny until you realize that impellers sometimes fail where you don't get to call Hank. When rebuilding the genny water pump and it's spread out on the dinette, specialized tools like this are the difference in the enjoyment of the day.
Which when sizing, might be worth considering a size that works on all your impellers.
"Our weights are similar what allows your hull to run with lower power?"
I do not know the diesel Carvers well enough as we have not run with any over the years. We have run extensively with a 39 Carver aft cabin but it was gas powered and makes for no comparison value.
I can say that the Sea Ray 45 with 8.3's that we ran with many times would run with a higher shaft to water angle and that his hull was definitely more thirsty than ours - not sure which made the larger difference (similar weight / similar size). When we stayed together for longer trips (maybe 60/100 mile legs with 250+ overall) at around 17 knots he would typically get around 0.7 NMPG. On many occasions it would be noticeable as he would need to stop for fuel at a less desirable location(price or convenience). A part of that was his tanks held about 50 gallons less overall but much more of it was due to the amount being burned - on a couple of these trips he noted that I did not stop for fuel at any time. When he went up to the 19-20 knot area and left us behind he would get between 0.55 and 0.65 nmpg or so. On some posts I pointed out that we cruise at times each year with a larger 'paper' boating club on longer trips with between 10 and 35 boats at a time so there is always someone to run slower or faster with along the way.
Found a picture of the 45 Sea Ray with a few others rafted up - he is the one all the way to the left....
I do not know the diesel Carvers well enough as we have not run with any over the years. We have run extensively with a 39 Carver aft cabin but it was gas powered and makes for no comparison value.
I can say that the Sea Ray 45 with 8.3's that we ran with many times would run with a higher shaft to water angle and that his hull was definitely more thirsty than ours - not sure which made the larger difference (similar weight / similar size). When we stayed together for longer trips (maybe 60/100 mile legs with 250+ overall) at around 17 knots he would typically get around 0.7 NMPG. On many occasions it would be noticeable as he would need to stop for fuel at a less desirable location(price or convenience). A part of that was his tanks held about 50 gallons less overall but much more of it was due to the amount being burned - on a couple of these trips he noted that I did not stop for fuel at any time. When he went up to the 19-20 knot area and left us behind he would get between 0.55 and 0.65 nmpg or so. On some posts I pointed out that we cruise at times each year with a larger 'paper' boating club on longer trips with between 10 and 35 boats at a time so there is always someone to run slower or faster with along the way.
Found a picture of the 45 Sea Ray with a few others rafted up - he is the one all the way to the left....
SR have deep pockets accounting for less lift.. My ACMY design does put more weight aft butengins are midships and running angle much flatter than others with tabs down... Larger slow props are a two way street while they offer better efficiency they also offer more drag
have a friend with a SR 420 ACMY with V drives and 6Cs he can hit 28 kts while I max out at about 24. Don't know his weight.
have a friend with a SR 420 ACMY with V drives and 6Cs he can hit 28 kts while I max out at about 24. Don't know his weight.
"SR have deep pockets accounting for less lift.. My ACMY design does put more weight aft butengins are midships and running angle much flatter than others with tabs down... Larger slow props are a two way street while they offer better efficiency they also offer more drag"
Bruce - I think you are on to something here...
I think you may have hit on one of the significant contributing factors here. I am not accustomed to seeing or comparing boats our size and weights with props anywhere near your size. But here is an interesting fact that I do know....
When Bayliner first released the new 47 Piltohouse boat they cam equipped with much larger props (4" larger) and a lower trans ratios (2:6 vs 2:1). Those original boats showed different data as tested for rpm's, speed and fuel consumption then the actual 47's that were built and shipped with the smaller props and reduced transmissions. Somewhere around my house I have copies of the original boat tests detailed data recorded with fuel use monitors as they often do with these tests - I know that is shows a large difference with the exact same boat with these changes.
Anyway - if it has any value to anyone I will search it out and scan it.
Hope this helps
Bruce - I think you are on to something here...
I think you may have hit on one of the significant contributing factors here. I am not accustomed to seeing or comparing boats our size and weights with props anywhere near your size. But here is an interesting fact that I do know....
When Bayliner first released the new 47 Piltohouse boat they cam equipped with much larger props (4" larger) and a lower trans ratios (2:6 vs 2:1). Those original boats showed different data as tested for rpm's, speed and fuel consumption then the actual 47's that were built and shipped with the smaller props and reduced transmissions. Somewhere around my house I have copies of the original boat tests detailed data recorded with fuel use monitors as they often do with these tests - I know that is shows a large difference with the exact same boat with these changes.
Anyway - if it has any value to anyone I will search it out and scan it.
Hope this helps
mine were 33X33 but had them redone to 33X31 to hit WOT. The first shop yielded the expended loss of top end speed but after taking them to a prop scan shop I got the speed back. In any event I always felt that the boat was set up as a stump puller.
FWIW - I had two Bayliner 45 foot Pilothouse boats before this one over about 10 seasons.
Two feet shorter , same beam , same dead rise, about 1,000 #'s lighter but with prop pockets.
They had 220 Hp Hino's with props at 22 X 21 X 4 Nibral and a similar trans ratio at about 1.85:1(if memory serves mw well).
The boat had less speed by about 2 knots but cruising at 15 knots had almost the same nmpg as the 47 at 15 knots - slightly worse on the 45.
33 X 31 is a very large prop and 2.9 is a very steep gear so you should be really powerful on movement.
I would guess that with those engines and that prop & gear your shafts will be very large (maybe even 3") as well to take the torque that it all produces. Your set up sounds pretty bulletproof to me as far as I can tell.
If only boats did not require maintenance we would be all set for good.
Two feet shorter , same beam , same dead rise, about 1,000 #'s lighter but with prop pockets.
They had 220 Hp Hino's with props at 22 X 21 X 4 Nibral and a similar trans ratio at about 1.85:1(if memory serves mw well).
The boat had less speed by about 2 knots but cruising at 15 knots had almost the same nmpg as the 47 at 15 knots - slightly worse on the 45.
33 X 31 is a very large prop and 2.9 is a very steep gear so you should be really powerful on movement.
I would guess that with those engines and that prop & gear your shafts will be very large (maybe even 3") as well to take the torque that it all produces. Your set up sounds pretty bulletproof to me as far as I can tell.
If only boats did not require maintenance we would be all set for good.