International Prop Question

alexander38 · Post by **alexander38** » Sun Mar 13, 2011 8:15 pm

Paul let's keep in mind the different torque bands we-re running gasers and 4 blade props react fast to our engines and put us on plane faster. But we do give up top end for them.

RWS · Post by **RWS** » Sun Mar 13, 2011 9:26 pm

prowlersfish wrote:I will take the 3 blades over 4 my self

yes grey is better then black or blue , But got to say I will keep my white . they where runing fine today

=======================================

My 10 Meter came from the original owner with a pair of 4 blade bronze and a pair of 3 blade Nibral.

With the gassers the 4 blade props were more efficient than the 3 but as I recall the 3 blade props gave a better top end.

prowlersfish · Post by **prowlersfish** » Sun Mar 13, 2011 9:39 pm

alexander38 wrote:Paul let's keep in mind the different torque bands we-re running gasers and 4 blade props react fast to our engines and put us on plane faster. But we do give up top end for them.

I think it has do with the boat more then the engines , some boats do better with 3 then 4 blades other don't most seem to get a hight top speed w/3 blades the cruse is mixed . ( mine is faster at cruse with 3 ) many Diesels seem to go with 4 mine is not one of them . 4 blades are a lot smoother . .

they both have pros and cons

alexander38 · Post by **alexander38** » Sun Mar 13, 2011 10:52 pm

My 10 Meter came from the original owner with a pair of 4 blade bronze and a pair of 3 blade Nibral.

With the gassers the 4 blade props were more efficient than the 3 but as I recall the 3 blade props gave a better top end.[/quote]

That's my point and I'm sticking to it.

prowlersfish · Post by **prowlersfish** » Sun Mar 13, 2011 11:21 pm

that right your prop knows what fuel you burning LOL

and 4 blades are more efficient but 3 blades are faster ???? HUH ??
( I know you mean at lower speeds )

As I said the both have pros and cons ( plus and minus )

every boat is different and they way they are used is different there is no fit all for sure

anyone on 5 blade wheels ??

alexander38 · Post by **alexander38** » Mon Mar 14, 2011 5:44 am

The prop doesn't care about fuel but where your engine makes torque at the lowest rpm to power it sure does.

prowlersfish · Post by **prowlersfish** » Mon Mar 14, 2011 6:42 am

alexander38 wrote:The prop doesn't care about fuel but where your engine makes torque at the lowest rpm to power it sure does.

low rpm torque your talking diesel right ?

there are many factors on what prop works best for your use. the boat , yes the power the speed of the prop ( gearing) and how you use it .

alexander38 · Post by **alexander38** » Mon Mar 14, 2011 8:34 am

No a 454 , your oil burners make it more than there to I know. Now your just pickin at it.

We'll just have agree to disagree. Again.

prowlersfish · Post by **prowlersfish** » Mon Mar 14, 2011 1:01 pm

Back to where it started

Rnd wrote:Well I finally got to go on my new to me 1989 11 Meter Express. As most of you folks know I had it shipped to Erie 2 days before Thanksgiving and shrink wrapped. With the snow and no marina key ect.ect. I have not seen it since.

So when I get on it today I find the props are: 24x25 4 blades, Shafts are 1 3/4 inch, also has dripless shaft seals.

She has 454ci. 350 HP each.

Question: Is this the factory set up? or has it been changed??

Previous owner did say he replaced shafts and props(soft grounding)

P.S. I thought my 32 ft. wellcraft St. Tropez was a fair sized ride. This thing is a BEAST!!! Hugh cockpit. Lovin it already

Thanks, Randy

With the size shafts and props I belive this boat was set up for diesel or gas w/ diesels bing very comon in them

Sea Play'n · Post by **Sea Play'n** » Sat Apr 30, 2011 12:13 pm

Rnd wrote:Well I finally got to go on my new to me 1989 11 Meter Express. As most of you folks know I had it shipped to Erie 2 days before Thanksgiving and shrink wrapped. With the snow and no marina key ect.ect. I have not seen it since.

So when I get on it today I find the props are: 24x25 4 blades, Shafts are 1 3/4 inch, also has dripless shaft seals.

She has 454ci. 350 HP each.

Question: Is this the factory set up? or has it been changed??

Previous owner did say he replaced shafts and props(soft grounding)

P.S. I thought my 32 ft. wellcraft St. Tropez was a fair sized ride. This thing is a BEAST!!! Hugh cockpit. Lovin it already

Thanks, Randy

I believe the stock props are 24 x27" Mine have also been dropped to 25" pitch to keep the revs up as the engines slowly get tired. Reduction on the 454 is around 3:1 and that is why the boat handles so well around the dock. (big slow turning props!)

Hugh

reelfishin · Post by **reelfishin** » Sat Apr 30, 2011 7:43 pm

Ours have a three blade but we do have diesels. They seem to do real good on our boat. I did wonder what a four blade prop would do on our boat. We really have great control of the boat with three.

RWS · Post by **RWS** » Sun May 01, 2011 7:20 am

The ratio on my 1983 International Express Cruiser ( nor mid cabin) is 2:1

When I bought the boat from the ORIGINAL OWNER in 2001, she came was wearing 4 blade props and had a spare set of 3 blades onboard.

Here's the detail:

Vessel 33' Trojan International, 13' beam, 12,500 lb dry,
Delta Conic Hull design, year 1983
Props: 4 blade 18x21 part# 0940 37171 and 37172

Three Blade Nibral Props: 17x22 (were 18 but restamped to 17)
Federal Equi-Poise

Prop Shaft is 1 1/4 diameter
Power - twin Crusader 454 cubic inch, 350 HP w/ Rochaster 4 bbl carbs
Velvet Drive transmission with 2:1 ratio

RWS

Sea Play'n · Post by **Sea Play'n** » Fri Aug 17, 2012 9:26 pm

Rnd wrote:Well I finally got to go on my new to me 1989 11 Meter Express. As most of you folks know I had it shipped to Erie 2 days before Thanksgiving and shrink wrapped. With the snow and no marina key ect.ect. I have not seen it since.

So when I get on it today I find the props are: 24x25 4 blades, Shafts are 1 3/4 inch, also has dripless shaft seals.

She has 454ci. 350 HP each.

Question: Is this the factory set up? or has it been changed??

Previous owner did say he replaced shafts and props(soft grounding)

P.S. I thought my 32 ft. wellcraft St. Tropez was a fair sized ride. This thing is a BEAST!!! Hugh cockpit. Lovin it already

Thanks, Randy

Hi,
I don't know if you ever got your answer about the props. My 11M sedan came with 350 hp Crusaders and 2.91 reduction Velvet drive transmissions. The props were 4 blade Federal 24" dia X 27" pitch. The engines had 1600 hours on them and lots of paint on the bottom. We changed the props to 4 blade michigan 25" pitch and the rpm came up to 4300 WOT. The reason the props can be huge is the reduction ratio. The large prop size makes handling a dream.
Hugh

jaahmez@hotmail.com · Fri Aug 17, 2012 11:08 pm

I have the 11M (1984) no dripless though, 1 3/4 and your mentioned 4 blade set up I beleive , as well as 4 trim tabs accross the transom. It's pretty sweet. I just put the boat in the water after two years of work on Thursday.
I am happy.

I'm not far enough in on runtime from the downtime to push the motors yet, so I can't give you speed/rpm. I'll get to it this weekend. It has the 350's in it.

todd brinkerhoff · Post by **todd brinkerhoff** » Sat Aug 18, 2012 12:49 pm

The only way you are going to figure out whether this is the proper set up is go out and run it and see if you reach 4400 rpms. The reduction gear on the 11M is probably close to 3:1. It allows you to turn those big wheels. You'll have to modify your pitch to reach the desired top RPM.

You have a great boat. Enjoy!

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International Prop Question

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