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  Props for 2000 225 EFI's on a 27' Guardian

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Author Topic:   Props for 2000 225 EFI's on a 27' Guardian
bwguardian posted 01-23-2004 06:34 PM ET (US)   Profile for bwguardian   Send Email to bwguardian  
Putting together a 27' Guardian and powering it with twin 2000 225 counter rotating EFI's. The boat will of course have trim tabs installed. The boat full of fuel (300 gallons) will weigh between 7,500-8,000 #'s. I am wanting to utilize four blade props and am thinking of 15" diameter by 19" pitch for a starting point. The boat will primarily be used for offshore fishing and I want to keep the boat hooked up in a following sea, this is the main reason for looking at at the 15" diameter. Any suggestions from you guys with the 27's.
Sal DiMercurio posted 01-23-2004 07:01 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
By all means the 15" diameter will be needed, but I have a feeling the 19p is going to be just a bit much because thats a very heavy boat.
I would start with the 15 x 19s & see where your rpms go, but I really think your going to need 15 x 17s.
Are we talking 4 stroke or DFI?
Sal
Sal DiMercurio posted 01-23-2004 07:02 PM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
Sorry, the EFI [ Mercs ] didn't click in till after I hit post bar.
Sal
Peter posted 01-23-2004 07:24 PM ET (US)     Profile for Peter  Send Email to Peter     
BWG - on a new to me 27 Whaler with Whaler Drive (310 gallon fuel capacity), I've got a pair of Evinrude 225s turning three blade 14.75 x 19 propellers. Top speed with nearly a full load of fuel is 44 MPH. If you go with four blades and 15 inches of diameter, you may need to reduce pitch to 17 inches. What brand of EFI 225s?
lhg posted 01-23-2004 10:00 PM ET (US)     Profile for lhg    
Those are really about 240HP engines, and are more powerful than the Optimax 225's. You will want to use 19" pitch Revolution 4 props, which according to Mercury's prop charts, should give you speeds min of 50, max of 56, depending on fuel load. Gear ratio is 1.75. Mirage Plus props will work if you want 3 blades.

Check out mercurymarine.com prop selector. Never buy a prop for diameter. That is best left to the engineers. Buy for prop style and use, then find the right pitch.

For a boat that size, I would STRONGLY recommend you order the boat for twin 30" engines, our if it is a used boat, install setback brackets to allow for the 30" twins. This will keep the engines high and dry and is the latest development in powering.

Peter posted 01-24-2004 06:17 AM ET (US)     Profile for Peter  Send Email to Peter     
Larry, sounds like he has the motors already in hand since they are 2000s and he said "EFI" in his post so I'm thinking they are either Yamaha, Suzuki or Mercury EFI, most likely of the 25 inch shaft variety since 30 inch shaft length is rare, particularly for twins. If Suzuki, propping with a 17 might be the way to go due to its smaller displacement. If Yamaha or Mercury, a 19 might be right because I recall that the Mercury 225 EFI is underrated and the Yamaha runs right around 225 HP.

With standard mounting, I don't think he will see 50 MPH out of a 27 foot Whaler and definitely not 56 MPH. As compared to the results given by the prop calculator in the Reference section here, the Mercury Propeller selector always seems to give me strange results, usually on the overpropping side.

bwguardian posted 01-24-2004 11:50 AM ET (US)     Profile for bwguardian  Send Email to bwguardian     
The engines are indeed Mercury's. I have been to Mercury Marines web-site and utilized the propeller selection guide and it does give me the Mirage and the Trophy series as selections (19" pitch). If I remember correctly, they do not show the diameters of the various propellers. In further research with Jeremy Davis of Brunswick Commercial and Government Products who often runs one of these rigs, he suggested the E.F.I. workhorses and also said 50+ m.p.h. should not be out of the question. Remember this is a straight center console (no cabin) and yes there is the extra weight consideration of the thicker glass. I have not conversed with him on props, but plan to. Most of the research I have done shows the 15" diameter four blades to stay hooked up in following seas; more blade surface. I tend to believe this information as my old 25' Outrage ran Mercury 150's with five blade props (the way it came) and it performed wonderfully in most all conditions. However, that is the reason for posting here as not all props are created equally and I would like to gather information from some of you 27 owners.

Peter, is your rig full cabin, cuddy cabin, center console cuddy forward, etc., etc.

lhg, the reason for the 15" diameter is for the style and use (to keep the boat from breaking loose).

Peter posted 01-24-2004 02:46 PM ET (US)     Profile for Peter  Send Email to Peter     
BWG - Here are the details: I have a 1989 cuddy cabin model with Whaler Drives, radar arch, full enclosure canvas, twin 2002 225 Evinrude Fichts (almost 240 HP each at the prop shaft) spinning the Viper 14.75 x 19 propellers. WOT (~5600 RPM) with all canvas up and about 250 gallons on board popped the GPS over 44 MPH.

Before I bought the boat the motors were propped with standard issue OMC 15 x 17 SST propellers and they were not getting a great bite. The seller offered to put new props on so it was fitted up with the Vipers by the Seller's local Bombardier dealer. Before that happened, I asked the local dealer whether to go with 4 blades instead of three and wasn't too excited about that. Maybe he just wasn't excited about Bombardier's 4 blade offering.

I might do a little better this spring because I'm not sure my "lefty" gearcase was up to the task of turning the Vipers as it blew up at the end of the season on a hole shot. It wasn't a Magnum gearcase like I have on the "righty". The Bombardier dealer tells me that Bombardier will be replacing the standard large V6 "lefty" with a new "lefty" Magnum case.

With the Mercury 225 EFIs, no cabin and a light load, you might catch 50+ MPH but I still think 56 is unlikely. With a full load of fuel I think you're probably going to see 45-47 MPH. I would start with 19 inches of pitch and see where your tachometer needles fall at WOT. You'll see quickly that its quite a big boat to push around.

bwguardian posted 01-24-2004 05:38 PM ET (US)     Profile for bwguardian  Send Email to bwguardian     
Peter,

Thanks for the info. I think the 19" pitch is going to be a good starting place for me. Does your rig ever tend to break loose or want to plow into a wave and bog the engines on a following sea?

Honestly, I do not intend or want to run the boat over 48-50 MPH other than at days end between the jetties to blow her out. I just agree with you and want the engines to be able to achieve 5,600 RPM at WOT as I believe this allows them to work at maximum effeciency.

What sort of range do you have (given an average day)? What is the farthest you have traveled in your rig?

Peter posted 01-24-2004 09:13 PM ET (US)     Profile for Peter  Send Email to Peter     
I haven't had it long enough yet to know it that well but I did take it out in some heavy seas before the gearcase blew and it did great, bow up and dry in typical Whaler fashion. I haven't yet had it in something like a 6 foot short period following sea but its ride characteristics so far are alot like my prior 18 and 22 Whalers, but just bigger and heavier. So far, no bogging and no breaking loose.

Compared to the Yamaha 225 EFI I had, the Fichts sip fuel. I have guestimated, based on Evinrude peformance reports, that at a 30 MPH cruise, the pair of Ficht engines are consuming about 18 GPH yielding an MPG of nearly 1.7. So at cruise with a 310 gallon capacity, I theoretically have about a 470 mile range leaving 10 percent in the tanks. Following the 1/3 rule, that means about 150 miles out!

At that same cruising speed, I'm guessing your Merc EFIs are going to consume something around 22 to 24 GPH so your range will be about 350 miles. If you are following the 1/3 rule, you should be good for 80 to 100 miles out and back with 6 to 8 hours of trolling in between.

I've only taken it on a 30 mile round trip so far. I was originally planning to bring it down from Cape Cod where I bought it, which is about a 120 mile ride one way for me, but chickened out and had it put on a truck. In hind sight it looks like that was the right thing to do because its likely I would have lost the gearcase during that trip. I'll do that trip once I've logged some more hours and have built some knowledge and confidence in all of the systems.

Sal DiMercurio posted 01-25-2004 05:20 AM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
Peter, I hope your fuel figures are a typo because 1.7 mpg is terrible for those DFI engines
If your only getting 1.7 mpg at cruise, you better bring those engines back to where you got them.
At cruise, [ 30 mph ] both of those engines should be getting close to 4...5.5 mpg each so you should be getting at "least" 2.....3 mpg between them.
When running twins, those engines work alot less then a single.
Sal
Peter posted 01-25-2004 10:47 AM ET (US)     Profile for Peter  Send Email to Peter     
Sal, my Whaler 27 with the Whaler Drive is the equivalent of a 29 foot boat. Besides that length, it has 10 foot beam, 2 feet more than a 25 Outrage! In addition to 8500 lbs of boat, gear and fuel, the radar arch, canvas, bottom paint, and all add up to a lot of water and wind resistance.

Unfortunately, Evinrude only provides one performance report for the Fichts in a twin 225 configuration, apparently with the same propellers I have. In that report, Evinrude shows 2 MPG as the best results for a 29 Angler. Top end speed is reported to be 55 which the speed prediction formula indicates the Whaler simply will not do.

I am suspicious of the propellers they claim they were using because because the slip I calculate for various reported speeds seems to be extraordinarily low. The results might be more believable to me if they were turning 21 inch propellers.

My estimated results based on average Evinrude Ficht 225 fuel consumption rates at various RPMs appear to resemble Yamaha's reports for the 250 HPDI on a 32 Regulator or 31 Jupiter. Those reports show best economy of 1.6 and 1.7 MPG, respectively. I suspect those hull designs are probably a bit more fuel efficient than the Whaler 27 hull. I believe my estimated results are also in line with performance reports by others with the 27 Whaler WD using conventional carbureted power such as Pete (a.k.a. Whaler27CC). Compared to those, I'm think I'm getting about a 30 percent improvement which is in-line with the general improvement DI makes over carbureted or even EFI.

However, once the new gearcase is on, I am going to check the toe-in to see whether its within Whaler specs and see if I can improve things a little. I'm also going to see if I can find a Merc dealer willing to loan me some 4 blade, 19 inch Revolution propellers to see if that improves things. It certainly would be nice to get 2 MPG but I'm not counting on it.

lhg posted 01-25-2004 05:40 PM ET (US)     Profile for lhg    
The information I used for the 19" pitch recommendation was from Mercury's prop catalog,(not widely available) and not the website. I too have found the website calculator seeming a bit high on pitch. The 3 bladed 19" Mercury Mirage Plus props do show a 15 1/4" diameter, but the better holding and accelerating Revolution 4 props would be less. All 4 bladed props have less diameter than the 3 bladed versions. The Rev 4 is still my recomendation, and possibly for your boat too, Peter, but in lower pitch.

I also think that Peter's 27 is heavier than the relatively light 4500# Guardian. It's a lot of boat for the weight!
And, as has been discussed here before, does not have the additional drag of the WD unit. So the Guardian will definitely be faster, if not loaded down with heavy accessories. I have been in a 27 Guardian (which is actually pictured in JimH's transom bracket reference article), OMC 225 engines mounted on a Salt Shaker bracket, and it would do 50.

As for relative performance of 225HP engines, don't underestimate the Merc 225 EFI's. In the Florida go fast and twin engined center console markets, you see the twin 225/250 Merc rigs everywhere, by far the most common brand.
So somebody must have determined they run fast.

For those of you interested, here is the data from Merc's prop chart on the 225 EFI: (for twins)

17" pitch, load range 9500-12600#, speed range 37-49 mph
19" pitch, load range 7200-11000#, speed range 42-55 mph
21" pitch, load range 5800-9000#, speed range 48-60 mph

You decide for yourself, but from my experience with these Mercury pro charts, they are extremely accurate. So this is where my 19" recommendation came from, and it also seems what C&GP said.

I also saw an article a few years ago in "Legends" that said a 27 Guardian with a pair of the Merc 300 EFI's, which is the same 3.0 liter power head as the 225, turned 60 mph.

Peter posted 01-26-2004 10:04 AM ET (US)     Profile for Peter  Send Email to Peter     
Larry, thanks for the info.

When BWG gets all done, I think he's going to have a rig that, when loaded with a belly full of fuel, gear and motors, is going to be pushing at least 7,500 lbs and he's going to want to prop it so he's not lugging the motors. Assuming that the Merc 225 EFIs are good for 240 HP at the shaft, then using the 180 as a hull factor constant (I've found the 27 hull seems to conform to this constant as well as the similarly shaped 18, 22 and 25 foot Dougherty hulls) and 7,500 lbs of weight, the speed prediction formula indicates about 45 MPH as a top speed. With a little fuel in the tank, he should catch 50 MPH. So your 19 inch recommendation for BWG looks to be right on the mark.

My motors spin the props through 1.86:1 drives rather than 1.75:1 drives on the Mercs. That doesn't seem like a big difference but at WOT that could represent nearly a 400 RPM difference. So for my boat, I think a 17 inch 4-blade prop might be on the low side and 19 inch might be on the high side. The only way to know for certain is to experiment with each.

bwguardian posted 01-27-2004 03:21 PM ET (US)     Profile for bwguardian  Send Email to bwguardian     
O.K., I just spoke to Jeremy Davis with Brunswick Commercial and Government Products and they run 15"(I believe he meant 15 1/2") X 17" Mirage props with the 225 engines. These props get the boats to 45-46 m.p.h. I additionally spoke with another local dealer who suggested the 14 5/8" X 17" Revolution 4 props. I have a pair of Offshore 14" X 19" props located, but I think I may pass on these.
lhg posted 01-27-2004 07:27 PM ET (US)     Profile for lhg    
The Offshore/Vensura props are only recommended for 135-175HP V-6's. Since you're looking for used props, the Mirage models will be much easier to find, since the Rev 4 props are only a year old. Use the medium size vent plugs.

Come back and let us know how the 17's run. I'd still bet on 19's.

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