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Is Propscan worth it

R

rmm

Regular Contributor
Props are on 1988 31' Tiar

Props are on 1988 31' Tiara and are currently 18x22.5. They are in generally good condition and were rehabed 2 years ago by a local guy that I believe works mostly by hand/sight after the were damaged.

There is a local shop that uses Propscan and wondering if it is worth the $140 each to have checked and retuned.

Thanks
 
"good question, I have the sam

"good question, I have the same year boat as you do. My props are original and appear to have never been hit or repaired.

I have been wondering the same. Is this like getting tires balanced and then you remember how your car used to feel?

In my case, I don't have any point of reference on my boat, I only have about 10 hours at the helm and about 300 in the engine room.


Bob"
 
This is my opinion.....ABSOLUT

This is my opinion.....ABSOLUTELY ! My boat is again underpropped and the 18 x 20 3 blade we have were shuddering at about 1500 rpm and shaking the boat a bit the 1st year we owned it... Brought the props to Propscan in southern NJ and the bill was $400.00. The graph of the props PRIOR to the tuning was all over hte place...like the best tuning they had was being dropped across the floor and kicked to the other side.... When we got them back..each scan looked like you had trimmed the bars with a papercutter...every line was perfect....

Mounted the props that spring and the boat was as smooth as could be. The extra little pitch and cup added to the blades mad the boat plane even quicker and we hit over 30 kts for the first time ! ZERO vibration throughout the rpm range
 
"Rm, Do it! You need data of r

"Rm, Do it! You need data of rpm and speed of what you currently have so they know what to adjust to. I added .375 to my pitch but i new that i could as i was turning to much rpm and i really don't care about top end it's about the cruise rpm. All props are under pitched from what is stamped from manufact.It really does'nt matter what it stamped though it's what your data is. You will be surprised on what it really is. Can't beat digital read out's vs. hammering in a pitch block by looks and feel. Propscan has tolerances they work to. Find out which one they are quoting you."
 
"Thanks guys, actually I found

"Thanks guys, actually I found a sheet tonight from the previous owner when they took the props to Propscan but that was like 7 years ago. Guess if I can find a prop puller will give it a shot.

Same problem here, I really dont have anything to compare to."
 
Worth every penny and I paid m

Worth every penny and I paid much more than that but that was many years ago.

The standard propscan shop practice is to serialize the props they work on. It should be on the data sheet. I have checked lately but my shop would do the check for free.
 
"RM,

Will it cost $140 just

"RM,

Will it cost $140 just to have them checked (scanned)? The Propscan shop where I live costs a lot more than that to have them checked and adjusted as needed. Ask the shop for a free loaner of the puller.

Erich"
 
"If the props appear to be run

"If the props appear to be running smoothly, and the boat performs okay, then why spend 140 bucks? If the idea is to save gas, that will buy a lot of gas!

Jeff"
 
We did the propscan project wh

We did the propscan project when the boat arrived from Florida and we did the restoration.

Net result after both props were re-tuned is that we got 2 knots extra @ 4000rpm and now we top the engines out at 4400rpm not the 4800 that we were getting

Fuel economy has improved and the engines are obviously much happier with the nicely swung props.

It cost us around A$800 for the two props to be done - well worth the cost.
 
Let's see now: $800 divide

Let's see now: $800 divided by $3.00 a gallon equals 267 gallons of gas. I hope your gas mileage got a LOT better!

Jeff
 
With petrol here being $1.35 a

With petrol here being $1.35 a litre and us using the boat every weekend (no off season in our climate) the fuel saving will be good but the extra speed and lack of vibration makes us even happier.
 
"Agreed, but note that I said

"Agreed, but note that I said IF the props seem to run smooth, then why waste the money? Obviously, if they were shaking like crazy, then it would be worthwhile.

Consider a misunderstood point about inboards: There will ALWAYS be vibration. The shock wave thrown off by each blade (outwardly) slams into the hull as the blade passes by, creating a vibration that's worse at certain speeds. (The "sweet spot" is not one of them.) For that reason an outdrive setup or outboards will always be smoother.

Prop shops have made a fortune keeping worried inboard owners happy when they didn't understand the above.

Jeff"
 
"Actually, the difference a se

"Actually, the difference a set of 'trued' props make is noticable on most hulls at any speed. Usually they are minor but add up over time; tachs, fuel flow meters and GPS are the tools to verify the changes. A prop or a set that is not compliant to the ISO prop standards does NOT have to produce a detectable vibration during operation. "Waste" is such a negative word; "choice" would be more accurate."
 
"I can remeber the substantial

"I can remeber the substantial difference in both ride and economy when we did our props but I did mentioned , they must have been pretty bad. At all speeds there would be a sinusoidal rhythm to the boat's feel as well as vibration and shudder underway."
 
"I have a 96 Carver 380 Santeg

"I have a 96 Carver 380 Santego with twin Crusader 454s
Manufacturer recommends a WOT of 4000-4400RPM
My engines peak at 3400 rpm with a cruising speed of 21 knts
Props are 21x20x13/8
Can anybody give me some information about what size and pitch they have found to be optimal
Gross wt 19,300"
 
"Robert

If you contact one

"Robert

If you contact one of the prop places or even look on-line, you can plug in the specifics of you boat and they can provide you with data as a starting point. Others with actual use information is certainly helpful but you can do some one-stop shopping that way..."
 
anyone have any specifics with

anyone have any specifics with regards to going with 4 blades. I am buying new props and have the option....currently running 22x22 3 blade nibrals....looking at 21x22 4 blade nibrals...
 
"Ted; for 4 blades to work be

"Ted; for 4 blades to work better than 3 blades, you pretty much need to be "diameter limited". I run the same engines/power as you but am forced to run 16 to 17" diameter props. I've got a pair of 4 blades to try and expect some advantage.
I'd be surprised if you saw a performance improvement with the 4 blades. You are already running pretty good size (diameter) props, so I would suspect low blade area is not a problem for you. You should gain some advantage in backing down and see some reduction in vibration, possibly."
 
"interesting dave...the prop g

"interesting dave...the prop guy was kinda surprised to find such large props on a boat my size, he said most are around 17-19"...

i am torn on what to do...any and all suggestions appreciated"
 
Ted...IF it means anything but

Ted...IF it means anything but just for comparison:

We had 18 x 21 3 blade with WOT around 5000.

Went to 21x23 4 blade and WOT of 3600

Top end speed was only 2 knots slower but pick up and bite in reverse were significant...No wake idle speed was 3 to 3.5 knots with the 4 blades it was 5.5 to 6 knots
 
"Ted:

Don't forget, the

"Ted:

Don't forget, the reduction gear ratio makes a HUGE difference in the pitch your engines can handle. The diameter is usually bounded by the strut - hull configuration.

If I rememmber the lecture from the propscan guru, you want to use as much available diameter as possible - what DD referred to as diameter limited.

Robert:

You may want to check a few of the Carver boards for that info. I concur with Al's recommendation to check in with the prop shop. Ideally, most sources will get you in the ballpark. As with most things, your boat's specific configuration may need a tweak. I'd say your current props are too large based on the limited info in your post. Before making any changes (spending $$$), make sure the engines are in good shape, are well tuned, the hull clean, and the running gear in good working order."
 
yep that is what the prop guy

yep that is what the prop guy said to me as well. I run a 2.57:1 trans so I can swing it.
 
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