New impellers baby !!!!

[dan144k]

@ar240owner If you were to put on the Lucky 13 cones, it may bring down rpms into the rev range. I am not an expert, was just a thought for you.

 

[swatski]

@ar240owner so when you slam the throttles all the way out the hole does it feel like spinning in mud?

 

[swatski]

This is from an older thread, but maybe worth revisiting:

I agree with what everyone is saying. And that is a great price @jcyamaharider for Impros, I paid $325 plus shipping for Concords last year.

Anyhow, the hard part is fine tuning the prop... Part of the problem is, in most cases we change the impellers when damaged. Which makes it rather difficult to get a good feel for any differences between models - the new impeller will always feel a whole lot better than the one you just used to find some rocks with.
So, until you start swapping and repitching undamaged impellers in your boat, nothing else is truly informative.

Here is what @Speedling is running, and he knows his stuff. If I was running a 230, that is what I would do!


In my experience with 1.8l - I am honestly thinking the OEM prop with its longer blades is the best performer... I'm certain of it for a single engine boat, twins are little less prone to hole shot cavitation, so I am less certain. And with less blade surface, Solas should be the fastest. If you look at the side-by-side comparison with the OEM (or even Skat Swirl), Solas has much shorter, far less ovelapping blades.

Here is Skat Swirl, Solas Concord, OEM:
View attachment 33106

Regarding the Lucky 13 cone, I can not say enough good things about it. But, it is not a “one-size-fit-all” panacea for holeshot cavitation issues. For example, when I ran the L13 pump cone with a Solas Concord 13/19 prop, which gives me the worst hole shot cavitation, the cone did not help much for whatever reason. With OEM impeller, it was a different story all together. The Skat Swirl impeller falls somewhere in between. At any rate, you will have to tweak it to get best results - swapping spacers, boring the venturi nozzle and tweaking impeller pitch. Unless someone could tell me exactly what to do, I would not want to subject myself to it with a twin - I would just drive myself too crazy. You end up doing this (on top of swapping props or adjusting pitch):

Hmm, what spacers to choose...
View attachment 33108

Hmm, how much to bore the venturi...
View attachment 33107

Below are some excerpts and pics -- from that thread. Now that I think about it again... I wonder about your new Solas. I could be completely wrong, but I have a feeling those could be 13/19 Concords strait off the shelf. Which would explain the massively under-propped performance, and also the lack of any machining marks. I have had some Solas repitched and refurbished with the most expensive Impros "race finish" - and let me tell you, it is not even remotely close to the glassy finish of the new ones, more like groovy. I have also had them done in a local shop that does this blast finish - like the Solas in the picture below (middle). But once you mess with them, they are never again going to be glassy /mirror shine-finish. So, they must be able to bend them with no grinding and welding.

I would see if the impellers do have different pitches when you pull them. Which brings up another point - if you change the pitch by more than about a degree, you really need to grind and/or weld the OD to bring the blade /wear ring clearances back to specs, no way around it as I have learned talking and working with Glen from the Skat factory.


https://jetboaters.net/threads/who-...roup-buy-on-impellers.5568/page-4#post-144172
"In my experience with 1.8l - I am honestly thinking the OEM prop with its longer blades is the best performer... I'm certain of it for a single engine boat, twins are little less prone to hole shot cavitation, so I am less certain. And with less blade surface, Solas should be the fastest. If you look at the side-by-side comparison with the OEM (or even Skat Swirl), Solas has much shorter, far less ovelapping blades.

Here is Skat Swirl, Solas Concord, OEM:

Regarding the Lucky 13 cone, I can not say enough good things about it. But, it is not a “one-size-fit-all” panacea for holeshot cavitation issues. For example, when I ran the L13 pump cone with a Solas Concord 13/19 prop, which gives me the worst hole shot cavitation, the cone did not help much for whatever reason. With OEM impeller, it was a different story all together. The Skat Swirl impeller falls somewhere in between. At any rate, you will have to tweak it to get best results - swapping spacers, boring the venturi nozzle and tweaking impeller pitch. Unless someone could tell me exactly what to do, I would not want to subject myself to it with a twin - I would just drive myself too crazy. You end up doing this (on top of swapping props or adjusting pitch):

Hmm, what spacers to choose...

Hmm, how much to bore the venturi...

"

 

[ISLANDRACING]

When I saw this post I was just going to keep my mouth shut and not say anything....
Then a customer walked in and wanted me to install an impeller on a pump,,, an impeller that he bought somewhere else and paid almost 400$ for with the "repitching".
I'll admit I was a little disturbed that he bought the impeller elsewhere, so I just had to show him what he just paid 400$ for.
As many know we used to service impellers, but when hurricane Sandy hit we decided to give up impeller work all together. Shame because good talent going to waste....
...So I broke out the measuring tools, and measured the impeller right in front of him, as he read out the #'s I wrote them on the corresponding blades.
...long story short, he wasn't very happy.
How are you supposed to dial in ANYTHING when you're starting with THIS: ...then you're going to hear "oh its not that critical"

 

[swatski]

When I saw this post I was just going to keep my mouth shut and not say anything....
Then a customer walked in and wanted me to install an impeller on a pump,,, an impeller that he bought somewhere else and paid almost 400$ for with the "repitching".
I'll admit I was a little disturbed that he bought the impeller elsewhere, so I just had to show him what he just paid 400$ for.
As many know we used to service impellers, but when hurricane Sandy hit we decided to give up impeller work all together. Shame because good talent going to waste....
...So I broke out the measuring tools, and measured the impeller right in front of him, as he read out the #'s I wrote them on the corresponding blades.
...long story short, he wasn't very happy.
How are you supposed to dial in ANYTHING when you're starting with THIS: ...then you're going to hear "oh its not that critical"

@islandracing Thank you for providing your professional opinion and keeping this forum real.

 

[Ronnie]

If we are talking about Impros, I can't speak for anyone but myself, the 13/19 Concords I got from them work as advertised. That is better acceleration no noticeable loss of top end speed which I was told to expect but never materialized, the rpms are in sync throughout the throttle range and both engines still max at about 7,700. I recall tooling marks on at least one of the impellers but don't remember which one. That said, I'd buy from them again.

 

[swatski]

If we are talking about Impros, I can't speak for anyone but myself, the 13/19 Concords I got from them work as advertised. That is better acceleration no noticeable loss of top end speed which I was told to expect but never materialized, the rpms are in sync throughout the throttle range and both engines still max at about 7,700. I recall tooling marks on at least one of the impellers but don't remember which one. That said, I'd buy from them again.

I think the issue is, Impros used to be a different outfit, before they moved and all. They used to send the impellers back and forth to the customer getting back data and adjusting based on those data, free of charge, until dialed in the way it should be. As we know from previous threads, and I would be happy to find them for you again, they not only stopped doing that, nowadays they seem to be okay telling customers it is fine to have OD specs out of whack, because it will somehow work out fine.

I don't think anyone is attacking them. But if you read some reports here, and look at the pictures above, I think it is apparent the quality of that service leaves room for improvement.

Now, here is what I really think. The OEM impellers can be purchased new, not refurbished, for $150 shipped. Solas from Impros are close to or over $400 depending on shipping method.

Based on my small share of SIDE-BY-SIDE testing in a single 1.8 boat, not anecdotal evidence, I find those new OEMs to be superior to Solas Concords (new, repitched, refurbished, race finish, whatever). The design of Concords is quite different than the new OEM lending Solas an edge in smoothness and speed (perhaps), but not the hole shot power. I will be surprised if my experience with single pump YJB does not translate to twins, but am curious about it.

--

 

[ISLANDRACING]

Just to be clear nobody is mentioning names.
This is why I wasn't going to say anything, every time I put up a post like this ( this wasn't the first over the many years ) it stirs up crap.
There are many companies out there doing impellers, IR used to be one of them. ....and may be again ( haven't decided yet ) for the sole reason, if people are paying top dollar for work pictured in the above post, people can pay for work that will at least measure equal.:
Understandably, different companies have different ways of measuring impellers. ...meaning what measures 18 degrees on another companies gauge may be 20* on ours, that's fine... What isn't is that every blade is obviously OFF from each other! ...3 blades all 3 different with over a degree difference ...this is what (as i mentioned before) your'e going to hear "Oh that's acceptable" That is 100% BULL$HIT! Sorry not in my book! not with my money! and DEFINATELY not in my boat!
People look at things different ways. If I personally pay for something, I want it right! bottom line.
This is 100% the reason I started doing impellers for myself over 20 years ago.

 

[dan144k]

Note regarding the yamaha impellers. I have read for many years that there quality control on impellers was not very good. Many people have gotten brand new yamaha impellers with each blade at a different pitch.

Just some information I remember reading. Maybe some body more knowledgeable can verify?

 

[ISLANDRACING]

Swatski, I saw some of your posts on the impeller testing. Excellent work! I've been there done that. Takes a LOT of time and effort.

 

[ISLANDRACING]

Note regarding the yamaha impellers. I have read for many years that there quality control on impellers was not very good. Many people have gotten brand new yamaha impellers with each blade at a different pitch.

Just some information I remember reading. Maybe some body more knowledgeable can verify?

100% correct. You can take 10 of the same impellers ( oem solas, any brand etc ) brand new out of the box, all 10 will measure differently period. ...will all 10 move the boat forward, yes of course. does it make a difference? , to most no, but to some yes. Can there be gains by modifing/repitching,,, yes, but sometimes not... Ill admit ive seen some vehicles run the best with all messed up impellers with pitches all over the place... never any guarantees with impellers.

 

[swatski]

My own take on Yamaha OEM impellers is that the material (some kind of stainless steel alloy? definitely NOT aluminum) is fairly soft, as compared to Solas or Skats. That is good and bad. As far as specs, looking at my notes I have purchased at least three new OEMs in the last year or so, and I was fortunate to get good batches, with no substantial issues.

As far as the pitch measurements, those plastic angle measuring devices are okay, but if you are not a pro you may do better with a simple ruler, a sharpie, and a flat surface such as granite counter-top. I would say the most important thing to keep in mind, pitching is usually done to a target RPM, not a target angle. So, basically -- you must pitch it and try, in your boat.

A good shop will pitch perfect every time, no doubt. But they don't know your boat, and at the end of the day you still have to run it - to see where you are. I can tell you that even guys like Jerry Gaddis (of greenhulk forum) tweak all their new/custom pitched/RIVA-edition/whatever impellers to get the most out of them.

--

 

[swatski]

BTW - speaking of impeller choices, I would think that the Solas Concord would be the way to go for a MR-1 boat (budget permitting, as those are twice as expensive). Just based on the similarity of the blade and root design and superior quality of materials I would consider those a direct upgrade to the MR-1 OEM impeller (part number 6P6-R1321-10-00, as in @Bruce's post with other links, https://jetboaters.net/threads/impellers.9163/page-2#post-157041).

I don't know exactly what pitch for either side, but if 13/19 off the shelf was close - that would be a good starting point. If it ran close to 10,200 RPM on either side, one would just bend the other side prop a bit (on the trailing edge - in either direction - depending on what they run) to get them even and as close to 10,200 as possible at WOT.

In the past, Group K also suggested Skat Trak as a direct upgrade for MR-1s, it has a bit longer blades, and could work even better.

I don't know of anyone ever testing the 1.8 OEM impellers in a MR-1 boat. I almost got a 2009 242 LS at some point, in part to do just that, but that did not happen.

--

 

[Bruce]

I don't know of anyone ever testing the 1.8 OEM impellers in a MR-1 boat. I almost got a 2009 242 LS at some point, in part to do just that, but that did not happen.

I am not aware of anyone testing 1.8 impellers in a MR-1 powered boat. I assume that they would need to be depitched to reach max RPM. I know the 1.8 impeller design is improved. Do you think they would be close enough to be worth trying?

 

[ISLANDRACING]

...different size driveshaft

 

[Speedling]

I run the 14/20 solas on my mr-1 and i don't quite reach max rpms. 13/19 may be a little shallow though because i am 200/400 rpms away from max. At sea level i may get it. Perhaps i will find out if Bimini works out this year.

 

[Bruce]

I run the 14/20 solas on my mr-1 and i don't quite reach max rpms. 13/19 may be a little shallow though because i am 200/400 rpms away from max. At sea level i may get it. Perhaps i will find out if Bimini works out this year.

I know you have posted before but I believe you run 14/20 on both sides without any tweaking to get them to match and saw both gains at the low end and in top speed. Is this correct? How much gain did you see in top speed?

Are you seeing 9,800 RPM on one engine and 10,000 on the other?

Have you tried removing the air filters and or ribbons to see if the increased airflow would bring you back up to 10,200?

What do you think about running 13/19 on one side and 14/20 on the other?

@islandracing, thank your for your insight into these issues.

 

[Speedling]

I know you have posted before but I believe you run 14/20 on both sides without any tweaking to get them to match and saw both gains at the low end and in top speed. Is this correct? How much gain did you see in top speed?

Are you seeing 9,800 RPM on one engine and 10,000 on the other?

Have you tried removing the air filters and or ribbons to see if the increased airflow would bring you back up to 10,200?

What do you think about running 13/19 on one side and 14/20 on the other?

@islandracing, thank your for your insight into these issues.

My before and after comparison isn't fair.
My boat was well used. My oem varied 3 degrees on leading edges and over 5 on trailing. I had silicone missing in the pumps. Top speed was more like 42 than 52. My thought is to depitch one slightly but a 13/19 may be too much in my case.

I have filters pulled, ribbons deleted and velocity stacks installed.

 

[Bruce]

@Speedling, what is your top speed with the Solas 14/20s?

 

[Speedling]

@Speedling, what is your top speed with the Solas 14/20s?

Top speed ever was before tower and no other passengers with less than half a tank i did 52 mph gps (55ish dream o meter).
Did a short run the other day with full tank, cooler of drinks, cooler of food, wife, three kids, a friend, his coolers, tower up, bimini up etc etc. Niel and i ran side by side a bit and we both said 47 mph.