correct prop set up for e-tec

[BUCA T]

hey lads, i have a 50hp e-tec on a cruise craft rougue 14. This engine has a 13 7/8 x 15 stainless prop. My engine revs to 5250rpm, on the brp website it says that 50hp is achieved at 5750rpm. I was looking for advice as to what size,pitch prop would make this engine rev to 5750rpm. my boats wot speed and hole shot arnt as good as my 97 model 50 mariner that i used to have on the back. I dont want to start the whole e-tec war but advice on the prop would be apprettiated.


cheers buca t

[finding_time]

Buca

First up Buca post a pic of you outboard set in the running position on the transom ( from side on ) the motor may be to low atm! If that's all good then look at the prop!


Ian

[cormorant]

Surely the dealer who sold you the motor has made a suggestion??? Ask them and use some of the house props to try and see if it will do any better. Which style or part number is your existing prop? .


Was it tested after fitting or has any extra weight been added?

After the double oil period has finished will it rev ot a little extra?

There is an allowable range rather than a peak rPM so what is the allowable range for that motor?

Worth getting your existing prop worked and will that affect your warranty??

[FNQCairns]

Try and stick with the 15pitch part of the prop then beg borrow or steal a prop of any brand or material that is say around13.25 in diameter, this will get your revs up without sacrificing the economy or good cruise speed you would like to keep. it's hard as they seriously overlook what's needed to make slow boats work well in every single manufacturer line up of props. Then when closer look toward your leg height as mentioned above.

cheers fnq

[Jabba_]

As Finding Time stated, make sure you engine height is correct before playing with the prop...
Dealers are very good at setting the motor too low on the transom..
Take some pic, and post them up.. A picture like these will help.

This motor was set up too low by the dealer...
http://i468.photobucket.com/albums/rr41/acama/ETEC%20Height/P6190297.jpg
http://i468.photobucket.com/albums/rr41/acama/ETEC%20Height/P6190310.jpg

[BUCA T]

The engine is past its double oil period, no weight has been added to the boat, its a viper prop. When towing some one on a wakeboard ect it just doesnt seem to rip them out of the water as good ass the old engine. i tried to upload some pics but was havin dramas. the fin on my skeg is inline with the bottom of the v on my boat. is this to low? I would have talk to the dealer about it but they have closed down in gladstone cq.

cheers buca t

[Dantren]

Hey Jabba,

Are they the before or after pics??

Dan.

[finding_time]

. i tried to upload some pics but was havin dramas. the fin on my skeg is inline with the bottom of the v on my boat. is this to low? cq.

cheers buca t

Could very well be,;) try and get a pic up!

Ian

[BARRA73]

Buca T I have a 60hp etec with the same size 13 7/8 x 15p Viper prop and as soon as I get some money it will be getting replaced. My outboard runs great and WOT is about 5900rpm but to me the prop just doesn't feel right.. I will be replacing it with a 13 or 13 1/4 x 17 because I believe that a 13 7/8 is just way too big for an outboard of these sizes. Have a look at all merc, yammies etc of the same size and how much smaller the size of the props are and they seem to in my honest opinion to perform better so I firmly believe that Viper my not be the best props for 40hp to 60hp etecs. Give the guys at solas a call I reckon they could help you. Do whatever you can to get rid of the 13 7/8 size.

Cheers.

[Jabba_]

Hey Jabba,

Are they the before or after pics??

Dan.

They are before pictures.. The owner is raising that motor 2 inches...

[Jabba_]

The engine is past its double oil period, no weight has been added to the boat, its a viper prop. When towing some one on a wakeboard ect it just doesnt seem to rip them out of the water as good ass the old engine. i tried to upload some pics but was havin dramas. the fin on my skeg is inline with the bottom of the v on my boat. is this to low? I would have talk to the dealer about it but they have closed down in gladstone cq.

cheers buca t
PM me if you want me to host your pictures...

[Jabba_]

Buca T I have a 60hp etec with the same size 13 7/8 x 15p Viper prop and as soon as I get some money it will be getting replaced. My outboard runs great and WOT is about 5900rpm but to me the prop just doesn't feel right.. I will be replacing it with a 13 or 13 1/4 x 17 because I believe that a 13 7/8 is just way too big for an outboard of these sizes. Have a look at all merc, yammies etc of the same size and how much smaller the size of the props are and they seem to in my honest opinion to perform better so I firmly believe that Viper my not be the best props for 40hp to 60hp etecs. Give the guys at solas a call I reckon they could help you. Do whatever you can to get rid of the 13 7/8 size.

Cheers.
I agrea Merc make the best prop in the business

But before you buy a new Merc prop, give BRP's Rogue a go.. From all reports these prop go very well.. There similar to the Merc's Fury as in the way Pitch/Diameter Ratio... The fury is a top prop, fastest bass prop on the market todate, but they start at 23"...
The Rogue in 15" has a 13.25" diameter
and in the 17" it has a 13.00" dia...

And if your spinning a 15 Viper to 5900rpm, your rig will easerly spin a 17 to 5700rpm, and that in a 17 Rogue will be a kick ass set up....

Here copy and past from BRP news bulliten..


The 4-blade design of the Rogue provides quicker planing and higher top speeds in sternheavy boats. Flats boat operators will appreciate this propeller’s ability to lift the transom and accelerate cleaner in shallower water.

Because of the Rogue's slightly smaller diameter, when re-propping from an Aluminum or

Viper™ prop, we suggest selecting a similar pitched size (i.e. replace a 15 pitch Viper with
a 15 pitch Rogue).

[cormorant]

Sounds to low from your description.

If dealer has closed and there is no other local dealer write a quick note explaining the above to BRP and ask for a trial of a couple of exchange props. They will either help you or not.

I don't think the viper would be a prop for towing but haven't had a play with that size etec.

If the fitting dealer knew you were towing I would explain that to BRP as they want to have satisfied customers. Send them a photo of setup and what you told dealer what your use was going to be.

Why did the dealer close??

viper ......

VIPER Polished Stainless Steel Props: Fast! Speed!


3 blade performance, high lustre finish - Made for speed!
Its longer swept blades and a larger diameter give this prop a better grip on the water, faster acceleration and greater top end speed.


For those comparing props on different motors you need to take into account torque curve and gearbox ration and WOT rev range

[Dave_H]

Jabba, I must say it is always interesting to read what you have to say WRT setting-up outboard motors. I (like many I guess when it comes to working-out the correct installed height of a new outboard) am slightly confused by what appears outwardly by some to contradictory advice/information peddled by a majority.

My own boat (unfortunately 4000km away at the moment as I am away with work for a few months) is a 16 foot fibreglass runabout with a 90hp 2 stroke outboard swinging a 13 1/8x16P (from memory) Vengance prop installed with the cav plate around an inch or so above the bottom of the hull measured the way you have there. This has actually left a two inch gap at the top of my outboard transom mount, but I will be getting that looked at later when I get back home.

It performs well except for a tendancy to cavitate while hard conering when pushed very hard trimmed hard up in the last 1/8 of the trim range (where it will also start to pitch up and down a bit when it is light - just me on board), but to get it to cavitate like that I guess you might argue that I am abusing the engine/boat as normally I wouldn't see it given that I don't usually try and corner like a SMOC boat.

What I am trying to work out in what you've said (that the outboard you pictured was two inches too low) is just why it would be that much too low? Is it a weight consideration (looking at the pics you supplied I would envisage that the boat wouldn't be a small one to also have trim tabs fitted) that I can get away with in my instance because my hull has: A. a fairly slow hull speed (around 45mph) and B. is reasonably light (around 700kg in full fishing trim).

Thoughts?

Regards,

Dave.

PS; (forgot to mention): With that engine/prop combination it is spinning to 5500-5600rpm (right in the sweet spot for the manufacturers specs).

[finding_time]

Dave

I'll have ago at answering your question! the further the engine sits back from the transom the higher it can be! The above pic is of a bigger engine by the look of it and they tend to sit back further than smaller engines so you set them up higher!

[STUIE63]

probably also has alot to do with the vee of the boat Jabba's does look like a deep vee.
Stuie

[Jabba_]

Jabba, I must say it is always interesting to read what you have to say WRT setting-up outboard motors. I (like many I guess when it comes to working-out the correct installed height of a new outboard) am slightly confused by what appears outwardly by some to contradictory advice/information peddled by a majority.

My own boat (unfortunately 4000km away at the moment as I am away with work for a few months) is a 16 foot fibreglass runabout with a 90hp 2 stroke outboard swinging a 13 1/8x16P (from memory) Vengance prop installed with the cav plate around an inch or so above the bottom of the hull measured the way you have there. This has actually left a two inch gap at the top of my outboard transom mount, but I will be getting that looked at later when I get back home.

It performs well except for a tendancy to cavitate while hard conering when pushed very hard trimmed hard up in the last 1/8 of the trim range (where it will also start to pitch up and down a bit when it is light - just me on board), but to get it to cavitate like that I guess you might argue that I am abusing the engine/boat as normally I wouldn't see it given that I don't usually try and corner like a SMOC boat.

What I am trying to work out in what you've said (that the outboard you pictured was two inches too low) is just why it would be that much too low? Is it a weight consideration (looking at the pics you supplied I would envisage that the boat wouldn't be a small one to also have trim tabs fitted) that I can get away with in my instance because my hull has: A. a fairly slow hull speed (around 45mph) and B. is reasonably light (around 700kg in full fishing trim).

Thoughts?

Regards,

Dave.

PS; (forgot to mention): With that engine/prop combination it is spinning to 5500-5600rpm (right in the sweet spot for the manufacturers specs).

Firstly Ian (Finding time) and Stue are correct.. Also note the every boat is different, every motor is different and every prop is different.. So finding the sweet spot can be time consuming....

Now in regards to the pictures I posted, the boat in question is a 19ft Sea-swirl with a 3.3l 200hp E-tec, by the looks off it a 21deg dead rise..... Now if you take a look at the outer edges off the cav plate, they are below the line off the hull by approx 2"..
So in theory as the boat is cruising its cav plate is going to be under water.. Thats not good, the cav plate needs to be above the water whilst at cruise speed... So the owner is going to raise the motor 2 holes to start with then test,, and if the Cav Plate is still under the water at cruise, he is going to lift it again
Read this article for a much better explanation,, http://www.veradoclub.com/smf/index.php?topic=137.0

As for your prop cavitation while your cornering, well that is going to happen if your not trimming in your motor before you corner in... It sounds like you rig is set up spot on, 1" above is the general starting point, then you make adjustments from there. Different props can run higher in the water then others, so that need to be accounted for when fine tuning your set up.. Also the gear casing makes a difference also... Merc gear cases can usually run higher then any other brand.... The E-tec gear case is better then the old Ficths, but not as good as the Merc's....