OUTLAW EAGLE MANUFACTURING

Alumaman · Joined: 26 Jul 2005 Posts: 306 Location: Whitecourt

Hamilton 212 in a Muskwa is beginning to be "purpose designed" for carrying big heavy loads in skinny water. It's nice to have an engine impeller combination that can get that big load up on step in as short of a distance as possible.

Therefore you should be looking to run the biggest impeller possible.

To turn the impeller a given rpm, an engine must make at least as much HP at that rpm as the impeller absorbs at the same rpm.
For the 212 with the 3.4 kw impeller, the ZZ383 engine will max out at about 4000 RPM (depending on elevation) as HP absorbed begins to exceed the HP produced.
With the 4.0 kw impeller, the same engine would max out at 3700 RPM. Even though the ZZ383 can make 425 hp, it cannot get past 272 HP.
Generally fuel efficiency begins to suffer above 80% of max RPM, which for the 4.0 kw above setup is 2960 RPM.
Also impeller selection should be such that WOT falls somewhere between the peak torque RPM and the peak hp RPM.
For the 383 with the 4.0 kw impeller a WOT RPM of 3700 is such that it's LESS than the peak torque RPM of 4300. The engine CANNOT run in its most efficient range and will lug. Computerized engines can adjust for this, but old school carbureted engines may be at risk of damage. Maybe.

The ZZ383 in a 19ft sport is outstanding value. It will likely also work ok in a 21ft Muskwa with a 212, but it's likely going to be hard on fuel , and potentially disappointing if it had to be set up to run the smaller kw impeller.

RChadwick · Joined: 04 Sep 2005 Posts: 21

@Alumaman
How would the zz383 with the dual plane manifold fair in a muskwa,212 4kw impeller. With the dual plane Gm rated the zz383 405 hp@5250 and 458ftlbs @3500.
I like running as much impeller as possible but I wasnt sure if the zz383 in this configuration could do a 4kw efficiently.
Thanxs.

DiggsNWT · Joined: 14 Jul 2010 Posts: 64

Arthur · Posted: Sun Jul 18, 2010 3:49 pm Post subject:

What's the cost difference between a SD-309 and a 212?

DiggsNWT · Joined: 14 Jul 2010 Posts: 64

Alumaman · Joined: 26 Jul 2005 Posts: 306 Location: Whitecourt

Rob, I based my numbers on the 425-horsepower ZZ383. Its dyno is based on high-rise single-plane intake manifold. The dual-plane intake manifold which is used to avoid hood clearance issues, reduces power by 15-20 HP.
So this engine with the 4.0 kw should in theory hit the wall at 3600 rpm, with the impeller absorbing 250 HP. The 4.0 kw would be too course, for this engine, in my opinion.

Alumaman · Joined: 26 Jul 2005 Posts: 306 Location: Whitecourt

Diggs,
The LS3 6.2 litre
max 4000 RPM with the 3.4 kw
max 3500 RPM with the 4.0kw
Probably want to run the 3.4 with this set up

The LSA 6.2 litre SC
max 4500 RPM with the 3.4 kw
max 4100 RPM with the 4.0kw
Easily handles the 4.0 kw. However runs a roots style super charger, and prefers premium fuel . Big $$

I'm not sure how to calculate it but, it has me thinking. "How much better is the 4.0 kw at getting out of the hole than the 3.4? If the 4.0 has 200 lbs more engine weight behind it, then how much of that extra load carrying capacity is used up, just carrying that big block. " Hmmm.

Rapid Transit · Joined: 20 Jun 2005 Posts: 206

what about a twin ?

DiggsNWT · Joined: 14 Jul 2010 Posts: 64

Guest · Posted: Mon Jul 19, 2010 12:07 am Post subject:

I have a brand new 2010 Bratt Jet 19 footer, this would be comparable to the muskwa, just a little shorter. I have a ZZ 383 with a Kodiak marine kit on it, Edlebrock 600 Vac Sec. carb. 212 pump with small 3.4 Impellor. Engine revs at 4400 rpm wide open. Optimum cruising speed is 3400 to 3600 rpm, the boat is in the 35 to 42 mph range depending on up or down river. I have tested my fuel range and I get just over 200 miles to 51 gallons gas. This engine has lots of power for this pump, 4 adults, coolers, full fuel, and lots of junk in boat it does 53 to 54 mph down river wide open on Red Deer river. I have had 8 adults in boat and three quarters tank of gas and it gets up on step no problem. I'm very happy with this engine and pump combo. Robby C. did have the 4.0 impellor in boat for the initial test drive but the boat was a bit sluggish off the line, too much impellor. I believe Bratt Jet is going to put a CT 525 in one of the next boats built, and Rob was talking about doing a fuel comparison against the zz 383. Laughing

JET1 · Joined: 03 Jun 2010 Posts: 42

i hope someone chimes in so i dont sound like an idiot but doesnt a smaller impeller turning faster move the same amount of water the big one does going slow so if it uses 300hp to spin the big pump a slow speed and it uses 300hp to spin the small pump twice the speed the engine is working the same at both RPM using the same amount of fuel i know that sounds stupid but it should be true

DiggsNWT · Joined: 14 Jul 2010 Posts: 64

Rapid Transit · Joined: 20 Jun 2005 Posts: 206

Jet 1.... the only way you can turn the smaller impellor twice as fast is by reving your motor faster, the only way you can rev your motor faster is to put more fuel through it, don't forget they are direct drive, the difference is the amount of torque you have, giving you the ability to hold the desired rpm without having to work as hard to maintain = less fuel, and depending on the type of hull you have you may not need or want to turn 5800 rpm, which in turn = more reliability and longevity for the last few rpm that you would hardly, if ever use , sounds like the 19 ft bratt is matched up correctly for loads and cruising with the family, is the 525 going into the same style of hull ?

Guest · Posted: Mon Jul 19, 2010 8:16 pm Post subject:

I made a mistake on my Impellor size it is the standard 2.4, sorry about the misquote. Yes the CT 525 LS3 will go in the exact same boat, not sure when this is going to happen though. The incident with Bratt's demo boat was a head gasket, and that was on the GM High torque 383 iron block engine, this motor is alot less hp than the zz383 and the performance was noticible between the 2 boats, one of the owners said the zz motor was way more responsive. I believe the demo boat now has a zz 383 in it. I really like the boat, handles great, it has a true half inch keel in it, not 2 quarter inch pieces sandwiched together, lots of storage, open bow, zero porpusing. In this boat going to a big block would just be a waste of money, wieght, and fuel, I think the LS3 may work in this boat, I checked the dyno sheets against the zz 383 and the torque is good down low in the cruising range of 3300 to 3800. The LS3 is a very light wieght engine also.

Guest · Posted: Mon Jul 19, 2010 9:58 pm Post subject:

As for the question about matching your impellor to peak hp, I don't think this applies to pleasure boats, in my 19 ft Step Tech I found getting the engine to rev half way between peak hp and peak Tq worked the best for all round performance and fuel mileage in a sport boat. (not race boat) In the bigger pleasure and utility boats you want the rpm down lower close to your peak tq, reving the motor higher in big boats just burns extra fuel I have found, but also lugging your boat too much will also burn extra fuel. Every hull and pump combo is a bit different, so one has to experiment. The big cruising pleasure boats were never designed for big top speed, so to get a big boat to run over 55 mph takes huge HP, which burns huge fuel, these boats are cruisers, 28 mph to 45mph, this is the range you need to set up your motor and pump package to be the most efficeint. With my Bratt Jet the zz 383 I feel the best bang for the buck $$. This is my 2 cents worth.
I'll try and post a few pic's of my boats.