OUTLAW EAGLE MANUFACTURING

DOC · Joined: 17 Jun 2005 Posts: 329 Location: Whitecourt

I think that was the first thing i learned when i bought a jet boat; how to lie !! Steel Clement impeller from Roger Kehoe last spring was 900 C.

Hines · Joined: 05 Jul 2005 Posts: 304 Location: Red Deer

hey doc u learned bullsh---- long be 4 the riverlol pops in hand

DOC · Joined: 17 Jun 2005 Posts: 329 Location: Whitecourt

Hinesy are you drinking again ??

Hines · Joined: 05 Jul 2005 Posts: 304 Location: Red Deer

doc not me i have to keep that sled in control / boat is coming not fast but fun.

DOC · Joined: 17 Jun 2005 Posts: 329 Location: Whitecourt

Hinesy, some buddies and i are heading to Valemount this weekend, staying at the Alpine. Probably start at Allan Creek on sat, not sure about sun. DOC.

El Prosecutor · Joined: 13 Jan 2006 Posts: 23

Sorry to interrupt your guys' conversation, but I was wondering if either of you gentlemen might have an opinion regarding impeller selection? Shocked

It is for a mild 455 Olds setup lake boat w/ 12JC pump. (See earlier parts of thread) Very Happy

WILSON · Joined: 17 Jun 2005 Posts: 352 Location: Mexico City

Well...it is not good to assume...because we make an a$$ out of you and me... Laughing

BUT, if we assume:

1) You have 400 ponies on that mild 455 Olds, and you want to turn 5000 RPM's, you have to go to an A

2) Now, if you have more horsepower and/or want to turn less than 5000 RPM's, you have to go to an AA (Berkeley also calls them A2)

If you are going to turn 5000 RPM's or more, you must go to a Bronze or Stainless impeller.

The bigger the impeller, the easiest it will be to get the boat on plane. The smaller the impeller, the higher RPM's, and, in some cases, the greater top speed.

See the chart on http://www.berkeleyjet.com/products/impeller-info.htm to have a better idea on this.

El Prosecutor · Joined: 13 Jan 2006 Posts: 23

SouthIdahoGary · Joined: 15 Jun 2005 Posts: 295 Location: Wilder, ID, USA

IF top speed does not matter so much, IF you are just lake boating and are looking for hole shot and low end "grunt" to ski with, IF long easy motor life is of prime importance, go with an aluminum AA. When lake boating you have a lot more chances to jump it out onto plane and be quick and impressive than you do to let it run out for the amount of time and distance that it takes a jet pump to achieve top speed. Nobody around to watch you hit top speed, they are all way back at the beginning impressing each other with hole shot.

Pro aluminum-
You can buy 3 aluminum for one SS. Aluminum is easier to "clean up" and resharpen. YOU can do it with a file, a little patience and time.
Pro AA-
Put it in and run it. See what it does. If the speed is sufficient, even if it only turns 4150 rpm-GOOD! As to heat-It takes more "heat" to make more RPM. Let's think this through....since when is 4000 rpm "lugging"? I don't think you are putting more heat into the oil by running the motor full out at 4100 than you are running it full out at 5000! An experiment, drive your truck uphill in the highest gear you can maintain 50 mph. Now go back down and run it up the same hill at 50 mph in the lowest gear you can get 50 mph with and keep it ripped up. Watch your temperature gauge closely under both situations..... You want to achieve your goal with the least amount of revolutions. It sounds like you are a lot more adamant about long life and easy running than being the "fastest". My rule of thumb is for every 1000 rpm you increase you cut engine life in HALF. Let the torque of 455 cubic inches do the work. This is NOT a HP motor, it is a TORQUE motor. Bigger impeller is more efficient. Jet pumps LOVE torque. IF you want to turn it up more you can have the AA cut down. AA to A increases RPM by about 500 rpm. Sneak up on it. The differences between sizes is quite small. Study the impeller charts. Start big. Bring the pump back into spec. Replace the wearable parts. New wear ring, bearings, impeller. You will be amazed what a difference a pump tune up can make.

(Now, having said all that, Xerophobic, you should be looking at nothing but Stainless Very Happy

the above does not apply to you. You need RPM's (5500+) and speed and something that will last longer in sand and gravel and that will "hold" the HP without deflecting. You need speed to utilize the magic in an Aluminum Tunnel Cool

Probably an A- or AB. Brass or stainless wear ring. In the race boat it does NOT have an insulator and is "fastened" in place)

My $.04-keep the change-free advice is worth all you pay for it....... Rolling Eyes

As to manufacturer, all we use is American Turbine. I can call them on the phone and talk to someone actually working in the facility. They have always been more than kind and helpful and they are in the heart of the Northwest jetboat manufacturing country. Lots of experience to draw from. I consider them money in the bank and the go to guys.

WILSON · Joined: 17 Jun 2005 Posts: 352 Location: Mexico City

Ok.

If your estimate and RPM target is correct, probably the "A" impeller is the best choice.

An A impeller will demand 325 HP at 4700 RPM's

If you have more HP, You will turn more RPM's.

For your reference: I have a 350 HP engine (which I guess is giving me a REAL 320-330 HP because I'm no good on carburetor and timing setup)

I run 4900 RPM's with a "B" impeller. The same setup with an "A" impeller would be around 4600-4700 RPM's.

My 350 HP is a stock "hot" engine 350 C.I. (The famous "ZZ4")

I would guess a 455 is at least 50 HP more powerful. Go figure.

WILSON · Joined: 17 Jun 2005 Posts: 352 Location: Mexico City

Well...the advise above is made thinking in race boats.

Gary is right. If you want more force to pull skiers and less RPM's for a longer engine life, go get an AA impeller.

An AA impeller at 4400 RPM's will demand 325 HP.

El Prosecutor · Joined: 13 Jan 2006 Posts: 23

Just want to extend a sincere thank you to Wilson and Gary for the previous posts. This was a good, well-reasoned discussion of the pros and cons of running a larger impeller. Both make good technical points, and I think Wilson made a key distinction when he acknowledges that the decision depends on whether you are thinking "race boat" or "lake boat".
Thank you both for taking the time to give it serious consideration - I think I am going to go with the AA in the hopes of extending the life of the engine. I also can't wait to see how fast that baby will plane now!!

DOC · Joined: 17 Jun 2005 Posts: 329 Location: Whitecourt

Yep, i agree with the AA. DOC.

Xerophobic · Posted: Wed Feb 01, 2006 7:57 pm Post subject:

yes excellent post guys.

Can anyone expand on the no plastic insert behind the wear ring that Gary mentioned? That is the first I have ever heard of such a thing.
Shocked

Cheers

SouthIdahoGary · Joined: 15 Jun 2005 Posts: 295 Location: Wilder, ID, USA

In a pump set up for racing, we run exceedingly tight clearances. The smallest amount of debris can tend to gall impeller and wear ring causing the wear ring to try and rotate with the impeller. The plastic insulator that the pump manufacturers put between the wear ring and the housing (to fight electrolytic corrosion) will allow the wear ring, when trying to tag along with the impeller, to rotate inside the suction housing recess. Hence, doing away with it eliminates the problem. That being said, it poses some other challenges that are usually inappropriate in a daily use kind of situation. Tends to tear up wear rings and impellers necessitating remachining and you have to be checking these same parts on a regular basis. Also makes it necessary to have custom wear rings made at a higher cost than stock pieces.