posted 04-08-2006 07:35 PM ET (US)        

TEST CONDITIONS:

Air temperature = 45-degress
Water temperature = (about the same)
Canvas = Foward Shelter, Windshield, Flying Top
Fuel = 1/4-full tank

With Bombardier three-blade aluminum, 17-inch pitch:

RPM vs Boat Speed

5,500 = 46 MPH (engine speed may have been higher, more like 5,800--jimh.)
3,000 = 26 MPH (engine speed may have been higher, more like 3,200--jimh.)

With Bombardier three-blade aluminum 19-inch pitch:

RPM vs Boat Speed

5,400 = 51 MPH
3,100 = 31 MPH

posted 04-09-2006 12:05 AM ET (US)            

At idle speeds
http://smg.photobucket.com/albums/v427/jeff_rohlfing/?action=view& current=FirstSteps009.flv

posted 04-09-2006 12:15 AM ET (US)            

Wake at speed--notice small wake and slight toe-in on engines
http://continuouswave.com/whaler/images/castorPollux/wake.jpg

posted 04-09-2006 09:40 AM ET (US)            

The 17 inch props clearly do not have enough pitch. Assuming a WOT report for the 19s, I'd be inclined to try a pair of 21 inch pitch propellers (using the old OMC/BRP pitch designation methods) just to see what happens. My thinking is that if the typical pitch used with a 150 (1.86:1 gear ratio) was/is 19 inches, then 180 HP applied by a pair of propellers through 2:1 gear ratios and elevated just might be able to turn 21 inches within the upper part of the WOT range.

If the opportunity presented itself, other propellers I would try are:

posted 04-09-2006 02:27 PM ET (US)            

I agree with Peter's recommendations. The 20" Laser IIs would be the first I would want to try and then the 19" Stiletto Advantage Is.

If a 19" pitch set of props is what ends up being optimal, and *IF* Dave were to carry a spare for single engine operation, he would want to have a 15" pitch prop. You will generally go down 4 inches of pitch when going from two engines to just one.

posted 04-09-2006 10:04 PM ET (US)            

Jerry

posted 04-10-2006 10:16 AM ET (US)            

I settled on the 13.2 X 19 BRP props to take home with me. Apparently this is a new prop from BRP and it has a little more aggressive cupping on the blades.

Tom is right. I'm going to end up with a 17 or 15 inch prop as a spare, which I'll order in a few weeks when Uncle Sam gives me some of my money back.

The test with one engine was on the 13.2 X 19 prop, so I know that I can get on plane with the current props, however, you saw how difficult it was...I had to wobble the hull to break it out of the hole.

Once on-plane though, it ran fine, and I was suprised to see the high 30's in the MPH range with a single.

Also - one of the things that needs to be pointed out is that the river has a strong current. I'm still going to be interested in top speed in "still water" settings and after I monkey around a bit with the jackplates. Right now, the engines are jacked quite high.

Overall, I'm very pleased with the rig.

Thanks for the great comments and suggestions. I'm going to have fun this summer dialing her in and getting comfortable with operating a twin-engine boat.

posted 04-10-2006 12:03 PM ET (US)            

The boat was loaded with 1/4 tank of fuel (about 15 gallons) and 3 adult men as passengers for each test.

Douglas Zammit and I were the only "constant" passengers.

I'd guess Douglas weighs around 160, and I'm at around 180.

posted 04-10-2006 12:22 PM ET (US)            

I'm going to be a bit more conservative and say that the boat is running in the 49-50 MPH range. The top speed held by the GPS was 51.9 MPH, however we "saw" 52.7 on the readout for a flash.

I may have my directions mixed up (I'd never been boating on this specific stretch of water), but I believe we were going downstream towards lake Erie when I saw those GPS numbers on the 13.2 X 19 prop.

On the upstream side with those props, I was in the back checking the anti-vent plate levels and then just hanging on and marvelling at the sound of the motors. (Doug Zammit was piloting).

As I said before, I'm anxious to do some tests in a "stillwater" setting.

...but with an arch and full canvas up and three guys aboard..I was still impressed, and I think that with tuning the jackplate settings, I can get another few MPH out of the current prop setup.

My regret on the day is that I did not choose to fill the tank before arrival in Detroit. It would have been nice to have picked the props that worked best and then spent the rest of the afternoon "tuning" the boat.

With a nice weather forecast for this Saturday, I may take the boat to an inland lake with a quiet ramp and do just that.

posted 04-10-2006 12:30 PM ET (US)            

That makes sense. You've got all summer to play around with this. Enjoy it.

I suspect your top speed this weekend was more like 46-48 MPH. At 51 MPH thee props would be running with a -5 percent slip factor! Even with a slip factor of ZERO, the predicted speed would be 48.6 MPH.

posted 04-10-2006 01:18 PM ET (US)            

That's one sweet ride!

After you get the first 10 hours on those babies, you will notice an increase in the power. When my 90 was new (in the 1st 10 hours), I could only pull about 5,300 rpms, but once she got past 10 hours, 5,500 (with the same load) was easilly achieved. The power for acceleration was also noticably increased.

Considering that you are doubling what I have (twins vs. single), you might want to consider holding off on final prop selection until they are broken in - just a thought.

posted 04-10-2006 02:50 PM ET (US)            

Great job documenting your whole process. Kept me entertained all winter.

posted 04-10-2006 05:23 PM ET (US)            

I just answered an e-mail on that very same topic: How can I contact Lockeman's for a quote, and do I think the twin 75's would be adequate.

The answer is yes, I think twin 75's would be adequate, however you would definitely need a 17 inch prop for single-engine running, probably a 15 inch.

You can contact Lockeman's Hardware and Boats, on Jefferson Avenue in Detroit, Michigan if you are within a few hundred miles. They're on the web. Ask for Dave or Doug Zammit, and be sure to tell them to give me a bird-dogging fee!!!

posted 04-10-2006 07:13 PM ET (US)            

Perhaps I'll cross on over to see you guys sometime this summer.

I'll post more re: the teak deck once I'm truly finished.

There was some Hydraulic fluid spilled on the deck when purging the helm, and some other spots that I need to clean up, then I'm going to caulk the deck down and take the final photos and host them on Photobucket. I'll be able to share all the photos with JimH for an addendum I'd like to write to Jeffs22Outrage's article on his project...since I had the same problem but just went in a different direction for a solution.

posted 04-11-2006 12:49 PM ET (US)            

However, for point of comparison, with standard Yamaha black stainless semi-cleavers, I get ~5% slip at WOT on my 22 with 130 twins.

Awesome set up Dave. Now I'm going to have to work pretty hard not to come up with a reason to replace my perfectly good engines with a pair of E-TECs.

posted 04-11-2006 02:55 PM ET (US)            

Any way you cut it, at WOT, 180 HP is burning 18 GPH approximately...two stroke or 4 stroke. I expect the economy to come at no-wake and at cruise...not at WOT.

At idle the motors are very quiet and even when cruising they have a quiet rumble...but when you hit WOT, you've effectively lifted the hull to the point where you're hearing the motors noise and the props that are cleaving the water on the keel side of the motor..so you can hear that prop slap, which I think is why some of the guys in Jerry's video commented that it sounded like an airplane. Effectively, you were hearing the full exhaust and the props beating the water.

Even at WOT with the canvas up (reflects noise), you could carry on a conversation with passengers in the boat at a much lower volume than my old Merc 150.

posted 04-11-2006 03:28 PM ET (US)            

That is one of the first changes I'm making on Saturday morning, after I visit Sears for a racheting boxed end wrench with 1 1/16" grip for jackplate adjustment while on-the-water.

So, to answer your question, no, I don't yet have accurate fuel consumption data at this time, and given that I know I have to calibrate that transducer - based on it's erronious readings last summer - it may take a few weekends to sort that out entirely.

posted 04-11-2006 04:22 PM ET (US)            

The engines are very quiet at idle. One of Jeff's videos shows the boat at idle and you can very clearly hear the water swishing louder than the engines.

When the boat is cruising at around 3,000 rpms, it is still quiet enough to talk normally and be heard.

posted 04-11-2006 05:52 PM ET (US)            

The platform delivers solid throttle response, full-force hole-shot and a pleasing sound.

There is no smoke (I noticed a small puff of smoke when pounding the throttle from idle...but we're in a "double oiling" regimen for the next few hours on the motors).

There is very little sound at idle.

The shift cables are smooth and the BRP dual binnacle control offers a nice feel and "weight" when shifting from neutral into gear. My one complaint on this particular instrument is that I'd like to have the option, as Mercury offers, to sync the trim/tilt for general purposes, with the normal independent operation as a continuing option.

The SystemCheck Tachometers are easy to read and have a very clear display and the warning LEDs are easy to read and understand.

Overall, I think it will prove to be a great combination for my uses.

posted 04-12-2006 09:39 AM ET (US)            

Do you have a photograph that shows the new static trim?

What is the approx. total weight on the transom,
including jack plates?

posted 04-12-2006 10:38 AM ET (US)            

Static trim is not too bad - about the same as LHG's. I'll have to dig up a photo showing that..I think you'll see one soon here on CW.

Total weight on the transom, (assuming the plates weigh 30 lbs each)...would be approximately 700 lbs.

(320 lbs for each motor and 30 lbs for each jackplate).

I guess with oil and props, we're looking at more like 720 lbs.

The batteries are in the console, and the new teak floor weighs less than the old fiberglass molded floor, but I can't remember by how much (it's pretty significant).

posted 04-12-2006 12:26 PM ET (US)            

Something to think about with regards to which props you select: The comparatively dense air of the cold temps you tested the boat in will give better performance than the typical summer weather you are more apt to boat in.

I can see an extra 200-300 rpm and a couple mph at WOT in April or October above what I can wind up to in mid summer. Whether this is what caused Pat to see an increase the in RPMs he got out of his engine or whether there really is some kind of unadvertised break in period on the E-TECs after all is hard to call. I suspect more of the former.

In any event, at a minimum, I would look for props that get you right to or even a little past the upper end of the reccomended RPM band in cool temperatures. You will likely see the max RPM fall comfortably into the range in summer temps, and you will be better able to plane on a single engine if necessary as you will be running a lower pitch prop.

posted 04-12-2006 01:49 PM ET (US)            

The initial running of the engine was done in late May last summer (temp in the mid 50's to low 60's). It was in these conditions that the engine had less than 10 hours on it and was only able to pull 5,300. The engine was pulling 5,500 in early-mid August (temp in the upper 70's to mid 80's), so from my perspective, the engine was definitely stronger after this 10 hour break-in period.

Also, I had the boat out on Lake Superior last Sunday, and she was pulling 5,600 and 1.3 knots faster with a good load and a kicker on the back. That would make sense as the temperature and humidity were relatively low compared to August of last summer.

posted 04-17-2006 11:37 AM ET (US)            

When coming to a fast stop off plane the splashwell takes some spillover. The 1,000 GPH Rule that I installed last night should keep the area mostly dry (usually it’s enough to fill the small splashwell sump, but no more (about 1 liter of water).

Drifting in 1-3 foot Lake Michigan chop on a stiff North wind on Saturday resulted in no splashover when drifting stern-into the wind, however you can hear the exhaust burble under the waterline as the boat bobs around. In a big sea, I’d definitely want to set a drift-anchor to keep the bow into the wind, or at least take it on beam-to.

I installed the Navman Fuel 2100 Fuel Flow sensor on Saturday morning.

At idle with both engines, the fuel usage is not measured (0.0 GPH returned). Idling both at about 1,000 RPM results in a fuel burn of between 0.2 and 0.4 GPH. With one motor, it hovers around 0.1-0.2 GPH. At both motors at 1,000 RPM, I’m making about 5 to 6 MPH on GPS.

This fuel flow meter has not yet been calibrated, and it read quite high readings (inaccurate) for the Merc 150 (it was off by about 10 gallons at Isle Royale (readings were high, which is the more comfortable side of accurate!)). For the Merc, I was getting 2 GPH at idle (6 mph) and averaged about 2.7 to 3.1 MPG for the many trips I took with that rig (both idle and at speed).

Assuming the inaccuracy has remained the same (for comparison purposes), I think I’m in a good place for this rig. It appears to be exceptional at idle.

As I said before, I’m still learning to be comfortable with adjusting the speed, synchronizing the engine tachs and piloting the boat (all at once, that is), so it was difficult to get figures on the meter for consumption at speed because it took so long to try to dial in the right speed and course for the conditions. …I think the translations were looking like 2.5 to 2.7 GPH for a given speed…it stayed the same for nearly all settings except for around 3,200 RPM, which returned 32 MPH (GPS) and about 12.8 GPH on the meter.

Also note - the economy should improve slightly after break in.