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prop size and speed f 32
Posted: Sun Apr 11, 2010 6:25 pm
by 9rock
My Friend just has his maiden voyage in his 81 f 32 318's
At 3000 rpms he was going 13 mph with 16 x16 in props
does that seam rite ?
Posted: Sun Apr 11, 2010 8:26 pm
by ready123
My F32 came with 16x15 3 blades.
I believe he should be nearer 20/22 mph at those revs.
Did he play with the trim tab settings?
F32's like to run trimmed down somewhat.
Of course there are many things at work here to give different readings:
Clean bottom
accurate tachs
heavy or light loading of boat.
engine power
Posted: Sun Apr 11, 2010 8:55 pm
by captainmaniac
With my Chrysler 360s I run 16x16 cupped 3 blades, and at that RPM I get about 18-21 knots (depending on wave conditions and wind direction).
Posted: Mon Apr 12, 2010 9:55 am
by g36
mine is a 78 f32 with 318's and like ready i have 16x15 3 blade props. at 3000 at i am right around 21mph playing with the tabs sometimes a little fatster just depends on the water,wind and me, but within the 20-22 mph range that ready posted
Posted: Mon Apr 12, 2010 10:04 am
by wowzer52
Sounds like a dirty bottom but like ready123 said it could be any or all of the things he listed.
Posted: Mon Apr 12, 2010 7:08 pm
by 9rock
captainmaniac wrote:With my Chrysler 360s I run 16x16 cupped 3 blades, and at that RPM I get about 18-21 knots (depending on wave conditions and wind direction).
I just found out he has 360s 250hps, does ur boat have gen set . just to see if the weight is about the same. He told me also he may have went over a sand bar and bent the props but is not sure
He is trying to get a apples to apples comparison
9
Posted: Mon Apr 12, 2010 8:57 pm
by captainmaniac
Yes, I have a genny as well. One other difference may be tankage - I have the original 60us gallon tanks (total 120gallons). Trojan offered 120gallons as standard, but also had the option of adding another 100 gallons of fuel capacity. If he has those tanks as well (and they are full), he could be carrying another 1000lbs.
I assume he has trim tabs and knows how to use them? If not, poor trim and really bad weight distribution (or waterlogged hull) can also make it tough for him to get on plane, which could result in that speed as well.
Posted: Tue Apr 13, 2010 11:43 am
by wowzer52
My friend has taken out the trim tab pump of his F-32 to replace it but while he is waiting on parts he still runs 17kts at 3000rpm without trim tabs. It takes him a little longer to get up on a plane but then he throttles back and stays on a plane and runs right with me. Him and I ran together yesterday for a 20 mile run up the Columbia River. It's a kick in the pants to run side by side with another F-32. It gives me a chance to compare performance.
Posted: Tue Apr 13, 2010 11:49 am
by ready123
9rock wrote:captainmaniac wrote:With my Chrysler 360s I run 16x16 cupped 3 blades, and at that RPM I get about 18-21 knots (depending on wave conditions and wind direction).
I just found out he has 360s 250hps, does ur boat have gen set . just to see if the weight is about the same. He told me also he may have went over a sand bar and bent the props but is not sure
He is trying to get a apples to apples comparison
9
So the props are right for that power.
Still seems to be running slow for those revs...
Posted: Thu Apr 15, 2010 9:29 am
by bob wilkins
Rock
I have a 77 F32 with 360"s and 16 X 16 props.
At 3000 i'm between 18 and 20 mph depending on the seas.
Bob
Posted: Fri Apr 16, 2010 7:30 am
by TADTOOMUCH
I have chrysler 360 at 250 HP turnimg 16x16 cupped 3 blades and get 22 kts at 3000 rpms in moderate seas. Is he sure his tachs are right? What is his WOT rpm?
speed
Posted: Fri Apr 16, 2010 11:20 pm
by gettaway
transmission ratio?
Posted: Tue Apr 20, 2010 10:54 am
by Tuck
i'm not sure exactly of what size, etc, props i have on my 77 f32...i assume they're the original specs. i do know i have chrylser 318s (1045 hours on each) i also know i have one prop (starboard) with a slight ding in it, but nothing too bad (had it checked last week...going to be having it redone sometime soon).
with that said, with a good night last night...smooth water with little/no wind, i decided to get some of the fuzz off of the bottom and ran the engines up to 3100 to 3200 rpm. with that, i played with the trim and got it up to a gps speed of about 19.5-19.9 mph.
is that about right?
Posted: Tue Apr 20, 2010 11:03 am
by ready123
Sounds about right... depends on load, if it were light and clean bottom I would expect a little more, closer to 22 mph with a good engine.
I would be happy with what you got though, certainly not poor results!
Posted: Tue Apr 20, 2010 11:52 am
by Tuck
danka!
