Trojan Boat Forum

Just Bought a 1975 f26 and the original owner had added 8 inches on the bottom of the keel starting from the front all the way to the back this brings up my question will adding this keel extension help or hurt in reguards to planing,"stability",and well just all around drag issues.

1975 f26
318
14x10

I would expect it to hurt all areas of performance. Do you believe the designer got things so wrong?
I think it is far more likely that the user was operating the boat improperly to conclude it needed that mod.... or was really only interested in running at displacement speed.... which would have been done better by switching to a displacement hull designed boat!

Did you buy the boat without a survey and in-water test???

no i tested it in the water but didnt reallly relize it til i drove it home 300 mile up the east coast but another thing is i do belive this boat has a oversized rudder so what whould u advise remove the keel extension and get a smaller rudder

Try and search the forum for threads on the F-26, I remember that someone did add a keel extension to their F-26. Can't remember who it was, but I'm pretty sure there was some info and photos posted about it. The deeper keel and larger rudder should help in tight quarters, but will also add some drag and limit your top end. I attached a photo of my 75 F-26 stock rudder and you can kind of get an idea of what the original keel looks like. I can take better photos for you if you want when I haul the boat in november


[/img]

yea the member was chucka i bought the boat from him but with the keel extention when a side swell comes by it takes the boat of a 180 degree ride and by adding the bigger rudder does that really make a difference good or bad?

1975F26 wrote:yea the member was chucka i bought the boat from him but with the keel extention when a side swell comes by it takes the boat of a 180 degree ride and by adding the bigger rudder does that really make a difference good or bad?

Huh??? "when side come by it takes the boat of a 180 degree ride"
what do you mean ??

sorry tired long day when a swell passes under the boat it take the boat and swirls it right around the other way i belive this is bc of the extension and bigger rudder i have

That sounds pretty normal for the F-26, with a following sea keep your trim tabs all the way up. You want to make sure you keep the nose of the boat up so your bow won't dig in causing you to pitchpole. If anything the keel and bigger rudder probably would help a little. What speed are you at when you're experiencing this?

like 14.5 mph my problem i want the boat to go faster like just 20 -24 it takes forever to go anywhere i am changing the prop this week to a 14x 9 hopefully that makes a differnce bc i cant get over 3200 wot

You're going in the right direction with the prop, that should give you an increase in rpm and might help your speed issue. Depending on conditions, with a 318 you should be able to cruise around 15-17kts at around 3000 rpm and reach close to 25kts at 4000rpm. Not sure how much the keel will effect those numbers though. Let us know how you make out.

Hi Guys,

I can't resist chiming in with my two cents.

I don't think that changing the prop is looking in the right place. I recommend a) getting the trim tabs working. [The pump ran, but the control valves weren't functional when the boat changed hands. The tabs were set for running about 2600 - 2800 RPM, which was my usual cruising speed ] and b) tuning up the engine, with a focus on making sure the carb is clean. I got 4000 RPM with the 14 dia x 10" pitch prop after the keel extension and oversized rudder were added to the boat. I was too cheap to pay for the gas so I never ran it with the secondaries kicked in for more than a few minutes. Here is an excerpt from one of my posts from Aug. 2006: http://www.trojanboats.net/wforum/viewtopic.php?t=67

Rudder increased in size from 12" h x 5" deep with 1" dia shaft to 17" h x 12" deep woth 1.25" dia shaft. Keel extended ~6 inches from original lines.

Here is what I measured. This is the average of two runs in opposite directions.
rpm knots
2,600 10.9
2,800 12.3
3,000 13.4
3,200 14.5
3,600 16.1
4,000 18.2

This Speed and power data is not a precise science. These measurements are very sensitive to loading the boat. One person on board and half a tank of fuel yields better performance than full tanks and the whole family on board.

I had the prop scanned earlier this year and it was in spec.

When I was showing the boat at the beginning of August , we were getting about 3500 - 3600 RPM. It's normal to drop off the top RPM after the boat's been in the water for a couple of months. It 's clearly dropped off more. We had a conversation about some bad fuel picked up along the way. I would replace the fuel filters and try some carb cleaner, make sure the plugs are clean, and check the timing. If that doesn't recoup some speed, I would think about a carb rebuild. last time was 2005.

Best,
Chuck

I would definitely get the trim tabs working first. This would explain what you experienced with the following sea and could cost you some rpm at top end.
With this new info, it wouldn't hurt to do plugs, cap, rotor and fuel filters as chuck stated, to see if you can get things back where they are supposed to be before you try and mess with the prop.


Regarding the prop. I've tried mine without a cup and with a full cup. The performance was much better with a cup than without. Adding a cup will cost you a couple hundred rpm so you would have to drop a degree in pitch.

Sounds likr cleaning the bottom wound be a start . The larger rudder is a plus as trojan got it wrong on many boats . The keel will slow you down some for sure , many be cucka can tell you how much , the rudder many slow it down but it woulnd not be even a noticeable amount if at all