4 blade props for a 320 Sea Ray

[srdancer90]

I'm in need of some information, I'm looking to move from a 3 blade 18x 19 prop to a 4 blade 18x17 prop for my 32 sea ray. I have seen the CJR, and teinbridge advertised on the web, however when nI cintacted Sea Ray at the plant they had no spec on which prop to purchase as they did not outfit the 32 with 4 blade props.Has anyone done this switch and if so what prop do you suggest. It seems foolish to purchase $1400 worth of props on the recomondation of the individual who wants to sell you the prop

 

[topgun1185]

mine work great

 

[320Bob]

You should go through a prop shop to find out what the optimal 4 blade size is based upon your WOT rpm versus what your engine ratings. Also you most likely will need less pitch on the starboard RH prop compared to the port side due to transmission differences. I replaced my 3 blade OEMs with 18x18 Michigan DQX Nibral 4 blades but I need to have the RH prop pitch reduced by 1/2" to eliminate the 130 rpm difference at WOT. The new props cost $2,200 installed and were covered under an insurance settlement. I got better fuel economy and low end torque plus smoother operation. You need determine if this is enough benefit to justify the cost. A simple prop tuning might yield some benefit for much less money.

 

[hack4alivin]

You should go through a prop shop to find out what the optimal 4 blade size is based upon your WOT rpm versus what your engine ratings. Also you most likely will need less pitch on the starboard RH prop compared to the port side due to transmission differences. I replaced my 3 blade OEMs with 18x18 Michigan DQX Nibral 4 blades but I need to have the RH prop pitch reduced by 1/2" to eliminate the 130 rpm difference at WOT. The new props cost $2,200 installed and were covered under an insurance settlement. I got better fuel economy and low end torque plus smoother operation. You need determine if this is enough benefit to justify the cost. A simple prop tuning might yield some benefit for much less money.

"Smoother operation" compared to what? Not trying to be a smartass here, but what is the baseline for comparison? Now I could see a little change in fuel economy, but how many hours would I need to run to make the $2200 cost justification? I think it would take a very long time to come out even on that deal.

 

[320Bob]

"Smoother operation" compared to what? Not trying to be a smartass here, but what is the baseline for comparison? Now I could see a little change in fuel economy, but how many hours would I need to run to make the $2200 cost justification? I think it would take a very long time to come out even on that deal.

Hack, smoother operation was less vibration. As far as cost justification, I am not recommending replacement. The improvements for me were incremental not monumental but my props were damaged beyond repair and had to be replaced. The improvement I got would not justify the cost to someone who simply was looking to upgrade unless cost was not an issue.

 

[hack4alivin]

Hack, smoother operation was less vibration. As far as cost justification, I am not recommending replacement. The improvements for me were incremental not monumental but my props were damaged beyond repair and had to be replaced. The improvement I got would not justify the cost to someone who simply was looking to upgrade unless cost was not an issue.

That’s my point, I thought about this before but I could not justify the change. As far as a smoother operation, mine do not vibrate now, so changing for the sake of gas consumption just does not make sense.

 

[Away Point]

I was contemplating a similar move last season, and ended up going with a CNC'd precision 3 blade prop.

You might find this interesting...
http://www.acmemarine.com/faq.php

This photoshopped images shows the difference in blade surface area between my old and new props.

 

[Vince_nj1]

I was contemplating a similar move last season, and ended up going with a CNC'd precision 3 blade prop.

And? Do their claims hold up? Do you now have Revolutionary Performance & Exceptionally Smooth Operation? :huh:

 

[hack4alivin]

Don’t get me wrong here folks; I am not saying a new prop whether it is 3 or 4 blade is not a good idea. But the OP is asking about making the switch to a 4 blade prop and what performance he can expect from his investment. If the current prop(s) are not damaged and do not need replacement I just can’t see changing them for the purpose of performance only issues. I think it will take too long to recover the investment dollar wise. Now if you are looking to have a couple of spare props around for that “just in case” issue, than have at it.

 

[Away Point]

And? Do their claims hold up? Do you now have Revolutionary Performance & Exceptionally Smooth Operation? :huh:

Over all, yes. Wasn't really having problems with the original props, but was hoping to improve mpg.

The mileage did improve, but not significantly (0.2 mpg or so). But in every other regard there is a noticeable improvement.

Low speed handling is more responsive. More prop lift underway definitely requires significantly less trim tab. I have no way to measure, but I do believe the boat is smoother and quieter underway.

In short, other than cost, I gained in every regard. I've been pleased with the choice, and would do it again.

Ron at Wolverine Propeller did an excellent job of interpreting all the knowns to choose the correct diameter and pitch. With my feedback on WOT RPM with the old props, and after measuring the old props, his prop selection nailed it. WOT is at 4,400, just as it should be.

I highly recommend calling Wolverine Propeller. Ron lives and breaths props, and isn't stingy in sharing his knowledge.

http://www.wolverinepropeller.com/

 

[Havana Shamrock]

I see this thread a lot here and now a buddy in work was asking the same question about his 320. I cant see the cost of new 4 blades if all your getting is a minimal fuel savings. wouldnt sea ray have turned the boat out with 4 blades from the factory if it where a huge difference? mine where re-pitched over last season and the boat is very smooth.no vibrations,,, :huh:

 

[KayKook]

wouldnt sea ray have turned the boat out with 4 blades from the factory if it where a huge difference? :huh:

Since it's not a huge difference, and their cost for 3 blades compared to NC milled 4 blades is higher, They decided it' s not worth the cost. The 4 blade DQX's and EQY 's(which SR buys for many of their larger inboard boats) are really a better choice for overall efficiency. If you can afford it, it's a better choice.

 

[Woody]

Over all, yes. Wasn't really having problems with the original props, but was hoping to improve mpg.

The mileage did improve, but not significantly (0.2 mpg or so). But in every other regard there is a noticeable improvement.

Low speed handling is more responsive. More prop lift underway definitely requires significantly less trim tab. I have no way to measure, but I do believe the boat is smoother and quieter underway.

In short, other than cost, I gained in every regard. I've been pleased with the choice, and would do it again.

Ron at Wolverine Propeller did an excellent job of interpreting all the knowns to choose the correct diameter and pitch. With my feedback on WOT RPM with the old props, and after measuring the old props, his prop selection nailed it. WOT is at 4,400, just as it should be.

I highly recommend calling Wolverine Propeller. Ron lives and breaths props, and isn't stingy in sharing his knowledge.

http://www.wolverinepropeller.com/

What mpg did you get before the change? I'm guessing that a .2mpg increase would be a big on a boat like yours.

 

[Away Point]

Since it's not a huge difference, and their cost for 3 blades compared to NC milled 4 blades is higher, They decided it' s not worth the cost. The 4 blade DQX's and EQY 's(which SR buys for many of their larger inboard boats) are really a better choice for overall efficiency. If you can afford it, it's a better choice.

Of course opinions vary, but Ron at Wolverine Prop believes 4 blade props are not the best choice for pocket drive hulls.

 

[Away Point]

What mpg did you get before the change? I'm guessing that a .2mpg increase would be a big on a boat like yours.

I'll take all the gains I can get!!! :grin:

I went from averaging a shy 1 mpg to just slightly over 1 mpg.

I do not have any fuel-flow measurement, but I do keep good notes, and make every effort to fill up in a consistent fashion. Between logging nearly 2,000 miles over the season, using the GPS to track miles traveled, and generally being within a 3 gallon variation between port and starboard tanks, I am confident in my numbers.

 

[srdancer90]

Thanks for all the input, my 3 blade 18x19 hit 4400, I have been told that I will lose speed at the upper end but will gain it in the mid range,I have spoken to several prop shops and over all their remark was " a little better " performance, none have said a significant noticable difference. However as many have said there is a HUGE price consideration, especially with Michigan nibral DQX, I have seen the CJR on the web which is high skew for $300 less each prop. I have contacted Sea Ray at the plant and no one there can give me a definite answer as to how the boat will perform with the change in props. A note the 2010-11 33 is using 18x16 (R) 18x16.5 (L) Teinbrige with a #4 cup. My best choice will to try to find a used pair( not nessessarly nibral) and try them. Thanks again to all.
2004 320 DA
T 350MAG MIE
1990 280 DA
T 5.7 350 260's