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  Performance of Banana Hull with twin Bearcat 55's

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Author Topic:   Performance of Banana Hull with twin Bearcat 55's
driller posted 03-23-2014 06:53 PM ET (US)   Profile for driller   Send Email to driller  
Hello. I'm in the process of setting up my 1973 Revenge with twin Bearcat 55's. It's a nostalgia thing - I'm not expecting to win any races. The same motors pushed my Aquasport 19-6 at under 30 mph WOT. Also not worried about the age or reliablity of the motors - they run like new and I have enough spare parts to keep them running forever. According to the specs, the Revenge and the AS are both 1,600lbs dry, though the Revenge certainly looks heavier.

I was wondering if anyone recalls any of the performance data relative to the early outrage 21's (also 1,600-lbs) which were sold with twin Bearcat 55's and singe 85's. My father sold lots of these boats from the dealership and I remember people raving about them, but I was too young to remember how they cruised - anything with twins was cool and fast to a 10-year-old. With the powerhead rated 55 four-stroke engines having a combined power of probably around 90-HP at the prope;;er, I'm hoping to at least achieve a decent planing speed. I won't be cruising offshore, mainly in lakes and inland waterways. Any input and opinions are welcome. Thanks!

seahorse posted 03-24-2014 09:55 AM ET (US)     Profile for seahorse  Send Email to seahorse     
I worked for a BW dealer that sold the Homelites and later the Bearcats.

Those 55hp engines performed about the same as the 40hp Evinrude on the same boat. They were quiet and smooth and trolled beautifully.

driller posted 03-24-2014 04:53 PM ET (US)     Profile for driller  Send Email to driller     
Yes, I figure I wont be much above the lower limit of 65 hp for planing this hull. I've spoken to a Bearcat mechanic who actually worked for Fisher Pierce and he said that they regularly tuned up test motors at the factory that would safely turn 8K and run with 75 hp 2 strokes on the same test boats. Crosley engine rebuilders have also told me that these engines will tolerate rpm ranges far in excess of factory settings as well as huge carberator jetting changes. With a few extra motors in the yard, if the stock 55's don't push the Revenge to at least the high 20's (mph), I guess I have a few options for experimentation, but reliability and economy are the main goals.

driller posted 03-24-2014 05:17 PM ET (US)     Profile for driller  Send Email to driller     
Unfortunately, I'm going to have to fill the notch in the transom to get the correct engine height. I've seem some radically wide spacing on older twin sets but I'd like to avoid using jack plates and want to keep the spacing at about 26" on center. If I set the motors outside of the notch, the spacing would be over 34" and I'd have to build up the transom to get the AV plates even close to the bottom edge of the hull. I'm thinking of building a filler piece out of aluminum so I can remove it later if I need to and still have a decent looking transom.
frontier posted 03-24-2014 05:46 PM ET (US)     Profile for frontier  Send Email to frontier     
In the 1974 Boston Whaler brochure it lists performance data for the 21'4" Outrage with dual engines as follows:
2-40's = 28 MPH
2-50's = 32 MPH
2-65's = 36 MPH
2-85's = 42 MPH

Single engine:
65 = 28 MPH
85 = 32 MPH
115 = 38 MPH
135 = 40 MPH
150= 42 MPH

Revenge single engine is about 10% less.

driller posted 03-24-2014 06:00 PM ET (US)     Profile for driller  Send Email to driller     
Well according to that data, I should be able to get in the neighborhood of the high 20's that I'm hoping for. The combined weight of the Bearcats is about 460, and from what I've read, the Revenge 19 should still be a little bow heavy - so planing off should happen about 30 seconds before I get to the other side of the lake! Thanks for the info!
Tom W Clark posted 03-24-2014 06:30 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
If, in 1974, an Outrage 19 could do 32 MPH with twin 40 HP motors, I don't see why a pair of Bearcat 55's wouldn't equal that on a Revenge 19
Tom W Clark posted 03-24-2014 06:32 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
CORRECTION: the 1974 Boston Whaler catalog shows the Outrage 19 doing 30 MPH with twin 40 HP motors
driller posted 03-24-2014 06:59 PM ET (US)     Profile for driller  Send Email to driller     
Well, I guess that still gives me some high hopes, even with the assupmtion that in 40 years at least some water may have found its way into the hull. I figure I have good cause to strip the bottom paint off.
driller posted 03-24-2014 07:01 PM ET (US)     Profile for driller  Send Email to driller     
Would mid 20's be a decent cruising speed for this hull?
ALAN G posted 03-25-2014 02:12 PM ET (US)     Profile for ALAN G  Send Email to ALAN G     
Driller, I own a 1975 Revenge 19...owned it since new. It currently has a 2004 135 HP Honda on it. Also on the transom is my 9.9 Evinrude for trolling/emergency get home power. The Honda weighs 480 lbs, and the 9.9 weighs 72 lbs. I have a mounted swim/boarding platform with stainless steel ladder which I would estimate weighs 20 lb. So I have 572 lbs on the transom plus the single battery is in the stern, just ahead of the transom. I have not had any performance issues with this amount of weight aft....and we cruise, fish, and waterski. The boat really does not need any trimming with the engine, although when up on plane, I will trim it out a bit, depending on speed. It starts to plane at 9 knots, is in transition 10-13 knots, and fully planing 14 knots and above. It cruises very nicely from 18 to 24 knots. I rarely open it up so I did not ever write down the top speed. The Revenge is a little bow heavy with deck, windshield, and railing. I also have a 15 lb anchor mounted on the deck forward. I don't believe you will have any issues with performance if your engines are running well. As you noted, you will have to carefully mount the engines as the hull bottom rapidly rises toward the sides. While my Honda is a 20" engine, the 9.9 is a standard 15" engine, and its anti-ventilation plate is about even with the bottom, mounted as far outboard as the lifting eyes permit. I am not sure if the Bearcats have power trim, but if not, you can experiment with different pin settings for the permanent running angle of the engines. I predict you will want the engines tilted down just one hole from level when on plane. This will permit the boat to plane off easier, and top speed is not an issue.

I think your project is a neat one and should be a nostalgia trip for boaters who remember the Bearcats and Fisher Pierce 4 strokes. Your biggest challenge will be doing a proper job filling in the transom center. I think your idea of an aluminum fabrication is a good one. If you are not familiar with the Transdaptor (sold for 13' Whalers which have 15" transoms for which owners want to mount 20" engines), you should look it up to get some ideas. A similar fabrication could work for you. Good luck, and please post some before and after photos when you can.

Al

driller posted 03-25-2014 06:29 PM ET (US)     Profile for driller  Send Email to driller     
Well a planing speed of 14 knots is good news, should have no problem getting beyond that. I'm impressed that you've owned your Revenge since 1975, that says a lot. What motor came on the boat when it was new?

The twin Bearcats turned a lot of heads mounted on the Aquasport - that boat was pretty rough looking yet people would consistently come up and take pictures of it whenever I launched it. I think they'll look great on the Whaler, and they sound great running together. I'll look into the Transdaptor before I start cutting up good pieces of aluminum. Thanks for the info.

ALAN G posted 03-25-2014 07:05 PM ET (US)     Profile for ALAN G  Send Email to ALAN G     
Driller, it originally came with a 1975 135 HP V4 Johnson. It was a great engine, was enough power for the boat, and I could have run it longer...but I got seduced by a brand new/one year old in box Evinrude 150 V6. That engine was amazing. We could ski with 6 people in the boat and it would easily pull a heavy slalom skier out of the water on a single ski...15 inch diameter prop as I recall. We then moved to California and found we could not use the boat on Lake Tahoe. So in 2005, on went the Honda 135. Of course the Honda can't match the initial pulling power of either two stroke engine, but the miles per gallon nearly doubled and the two stroke smell was gone. The Honda has been amazing in its miserly use of gas.

I tell my wife that I will be buried in the Revenge, but warn her not to dig the hole in wet lowland cemetery plots, or after a heavy rain when the ground is saturated, me and the Whaler will rise again due to its buoyancy!! :>}

Al

driller posted 03-25-2014 08:12 PM ET (US)     Profile for driller  Send Email to driller     
Al, I bought this Revenge with a 1988 150 Johnson V6 on it, which I figured would really make it fly but I'm not going to run it. I like 2 strokes but I'm all too familiar with the horrible fuel ecomomy of those OMC v6's. If the Bearcats are just too slow, I figured something like your 135 V4 2 stoke would be a good match, but hopefully it wont come to that. I remember one of the hot Revenge demos at the dealership where my father worked had a pair of the black and orange Johnson Stinger 75's. It flew but the guys in the boat yard really preffered the Outrage with the Bearcats on it. This was on eastern Long Island, NY. After hours we pulled in tons of bluefish on those demos. I remember as my father was pulling away from the dock in a Revenge hearing him say, "How's this for a company car!" This boat will be used in upstate NY, with an occasional bluefish run back on eastern LI (as soon as the ice melts).
driller posted 03-26-2014 08:29 PM ET (US)     Profile for driller  Send Email to driller     
Al, Does your Revenge have saddle tanks? I'd like to install a set but cant find any information on dimensions and installation locations. I dont think they were an option on the Renvenges until 1975. Paul
jwestwood posted 04-04-2014 11:20 AM ET (US)     Profile for jwestwood  Send Email to jwestwood     
I have saddle tanks that were installed on a 1974 Outrage 21. Because most of my use will be on inland lakes, I have no need for them and would be happy to sell them if they would work for you. You can call if you like 248-310-9638.
driller posted 04-07-2014 02:43 PM ET (US)     Profile for driller  Send Email to driller     
Jim, I checked the measurements and the saddle tanks that you have wont fit my Revenge. Thanks, Paul
ALAN G posted 04-10-2014 01:25 PM ET (US)     Profile for ALAN G  Send Email to ALAN G     
Driller, sorry for late response. I was out of town. My Revenge 19 has the standard under deck 40 gal aluminum tank...original equipment.

Al

adlert posted 04-11-2014 01:10 PM ET (US)     Profile for adlert  Send Email to adlert     
Al, are you still using the original fuel tank or has it been replaced? Just curious.
ALAN G posted 04-11-2014 04:31 PM ET (US)     Profile for ALAN G  Send Email to ALAN G     
Yes, still using original tank. The boat is trailered and always fresh water washed down after use. Salt and fresh water usage time is 50/50. I once pulled tank top to check and all was fine. I also always pull fuel guage access cover after use to keep top of tank vented and dry.

Al

driller posted 04-22-2014 08:08 AM ET (US)     Profile for driller  Send Email to driller     
I made my own transdapter out of aluminum and it can out great so I wont have to modify the transom to get the proper spread on the motors. I pulled the 40 gallon tank and it had some pitting on parts of the outside but the inside looked fine. With Florida marine tanks being at least 6 weeks out, I welded 1/8" aluminum plates over the worst areas, welded in a second pickup tube and today I'll be painting the whole tank with Gluv-It. It will likely last for years but I'll be ordering a new tank at some point this season anyway, just to play it safe. Bought a new dial for the sender as well.

Before I put the tank back in, I'm going to install a 1" drain pipe from the tank bed into the bait well - keeping the tank bed completely dry seems to be next to impossible, I think they should have been built with a drain from the factory. Here's a question - The boat is a '73 but the tank tag said the tank was built in '75. Could the original tank have failed in the first couple of years or is it possible that the hull was molded in '73 and not outfitted and completed for two years? When I opened the deck it looked to me like the original tank had never been out. Who knows.

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