25' C-Dory Cruiser--Permatrim
- Thread starter Fishbum
- Start date
I was curious about the under plate mount too, so I looked here.
Toyman - I share your experience with the Lenco tabs. The PermaTrim is going to do great things for you. I have the inadequate Lencos on my older (and heavier) CD25. When I first put the PermaTrim on I didn't think much of it. There seemed to be very little change until I relearned how to adjust the tabs and motor trim. I was hoping to get the bow down more. It would do that, but at a cost of top end speed and fuel burn, neither of which I could spare. Then I discovered if I used less tabs and let the bow run up where it always has, the PermaTrim would essentially lift the whole boat out of the water more and give me an increase in cruise speed of ~20% for the same fuel burn. I like that. Plus, the boat feels like it skitters along more like my 22 did. I like that, too. Plus, B~C told me that Honda 130 wouldn't care if I ran it at 4800 - 5000 rpm instead of 4200 - 4400, which gave me even more cruise speed on smooth water for the same 2mpg. I really like that. I adjust motor trim to get the max mph for rpm, and it always turns out to be with the prop parallel to the water surface. So I can just look back at the top of motor to see where the ideal is, and use the tabs for lateral trim. Simple and elegant. I really like that.
Don't give up. I imagine the Shipyard guy will tell you to relieve (grind away) the aluminum so it fits just right, which will be pretty easy to do. Or, he might trade you for a top mounting plate. But I would imagine there is a reason they went to the style they did for the Honda motors in that HP range.
And please, by all means, do not do like I have done and wait two years to report back on the way it all worked out. :embarrased
Toyman - I share your experience with the Lenco tabs. The PermaTrim is going to do great things for you. I have the inadequate Lencos on my older (and heavier) CD25. When I first put the PermaTrim on I didn't think much of it. There seemed to be very little change until I relearned how to adjust the tabs and motor trim. I was hoping to get the bow down more. It would do that, but at a cost of top end speed and fuel burn, neither of which I could spare. Then I discovered if I used less tabs and let the bow run up where it always has, the PermaTrim would essentially lift the whole boat out of the water more and give me an increase in cruise speed of ~20% for the same fuel burn. I like that. Plus, the boat feels like it skitters along more like my 22 did. I like that, too. Plus, B~C told me that Honda 130 wouldn't care if I ran it at 4800 - 5000 rpm instead of 4200 - 4400, which gave me even more cruise speed on smooth water for the same 2mpg. I really like that. I adjust motor trim to get the max mph for rpm, and it always turns out to be with the prop parallel to the water surface. So I can just look back at the top of motor to see where the ideal is, and use the tabs for lateral trim. Simple and elegant. I really like that.
Don't give up. I imagine the Shipyard guy will tell you to relieve (grind away) the aluminum so it fits just right, which will be pretty easy to do. Or, he might trade you for a top mounting plate. But I would imagine there is a reason they went to the style they did for the Honda motors in that HP range.
And please, by all means, do not do like I have done and wait two years to report back on the way it all worked out. :embarrased
My Honda 150 has the plate mounted on top as you can see below. The installation is very similar to the 90hp photo by Roger-Dreamer. An added benefit is that slow speed turning is improved due to the downward turned edges which provide a slight but noticeable rudder effect. Straight line tracking is also very solid.
From their website it looks like there are two different versions/part #s for 150 Hondas, dependent on single or twin engine application.
Smaller H9:
http://www.permatrims.com/M9_Silver_Permatrim_Hydrofoil_p/h9_silverhonda.htm
Larger M8:
http://www.permatrims.com/M8_Silver_Permatrim_Hydrofoil_p/m8_silverhonda.htm
The latter matches your measurements (roughly) and specifically says for single outboard apps on boats >23'. It also has the "hole" you mentioned.
I'm running into the same issue; the Suzuki 150 on boats >23' requires the larger foil @ $$219.95. :x
Smaller H9:
http://www.permatrims.com/M9_Silver_Permatrim_Hydrofoil_p/h9_silverhonda.htm
Larger M8:
http://www.permatrims.com/M8_Silver_Permatrim_Hydrofoil_p/m8_silverhonda.htm
The latter matches your measurements (roughly) and specifically says for single outboard apps on boats >23'. It also has the "hole" you mentioned.
I'm running into the same issue; the Suzuki 150 on boats >23' requires the larger foil @ $$219.95. :x
I mounted the Permatrim above the cavitation plate on the 130 Honda--and it did make a huge difference in both performance and ride.
The photos on the Permatrim site show a different version for the 135 and 150; since these are different engines than the 130, it appears that there must be a reason for the change. I am sure that Andy will give you a good answer why.
The photos on the Permatrim site show a different version for the 135 and 150; since these are different engines than the 130, it appears that there must be a reason for the change. I am sure that Andy will give you a good answer why.
I hope we can make the larger plate work, I think, in the case of Fan-C-Dory "Size Matters".
The hole in the plate is smaller that the sector on the trim tab so the trim tab can't be removed and re-installed after the PT is installed. Also the trim tab (on my motor) is less than 1/16" clear of the bottom of the cavitation plate - maybe grind off a little of the top of the trim tab ??
How do you grind Aluminum without clogging the wheel ?
The hole in the plate is smaller that the sector on the trim tab so the trim tab can't be removed and re-installed after the PT is installed. Also the trim tab (on my motor) is less than 1/16" clear of the bottom of the cavitation plate - maybe grind off a little of the top of the trim tab ??
How do you grind Aluminum without clogging the wheel ?
toyman":573real7 said:
You do not want to use a stone type grinding wheel to grind aluminum. As it plugs it up, the aluminum is getting forced into the stone and can build up sufficient pressure to make it explode. Best to use a disposable sanding disc or a coarse file. Even a wood rasp will cut the aluminum if you hold the plate securely enough.
It will be easier than it looks. The biggest concern will be taking off too much material once you get going.
Well, it's on, these old hands will take a while to become useful again.
I took ~2.5" off of the fwd end of the PT (Permatrim), cut the "slot wider, and removed about 1/8" off of the top of the trim tab to allow the PT to fit between it and the cavitation plate - all by hand. Looks OK, but now, what is the 5200 for ?
I took ~2.5" off of the fwd end of the PT (Permatrim), cut the "slot wider, and removed about 1/8" off of the top of the trim tab to allow the PT to fit between it and the cavitation plate - all by hand. Looks OK, but now, what is the 5200 for ?
Finally got out for some distance yesterday with the Permatrims installed on the twin 90s. Steering does take less effort as others have mentioned and with twins the trimming ability almost negates the use of our regular trim tabs. The big change is that I can push the bow down harder than I ever dreamed and something else I didn't really think of. Rough water handling. We were headed south out of Poulsbo yesterday against strong winds with gale gusts and the waves were built up from 4-5ft with the opposing tide. This type of surface usually forces us to throttle back to about 8 knots and bob our way through to avoid pounding. I guess with the virtual increase of our waterline, and ability to weight the bow more effectively, we are now enjoying the benifit of a bigger boat. We could hold 12-14 knots without pounding right into the wind and waves and we did so for miles down Port Orchard Passage with lots of wiper action. Cindie is sold and I am inspired to test more.
We did the install in the water with a ladder spanning the docks and careful handling of parts. I bolted one a bit different (bolt spacing) than the other but they are both solid of course and it only took about 2 hours for both.
We did the install in the water with a ladder spanning the docks and careful handling of parts. I bolted one a bit different (bolt spacing) than the other but they are both solid of course and it only took about 2 hours for both.
One of the major advantages of the Permatrims is to push the bow down. It is not necessarilly a longer waterline, but that you are pushing the sharp bow into the waves, rather than the relitatively flat bottom. Yes it makes a real difference in heavy weather.
However, you have to raise the motor up--because you do not want to have the bow down in either following, quartering or even beam seas. Having the bow down will cause "bow steering" and broaching. This can be a dangerous situation.
However, you have to raise the motor up--because you do not want to have the bow down in either following, quartering or even beam seas. Having the bow down will cause "bow steering" and broaching. This can be a dangerous situation.
I have run a couple of trips with a Permatrim on a Yamaha 150 and it is almost absolutely necessary given the weight distribution in the boat. It has Lenco tabs installed and the most efficient cruise was with the tabs almost full down and motor full down. We picked up about .3 mpg with the Permatrim as now the tabs are 3/4 down and motor trimmed up some. On the top end, I can get to 5400 rpm and 33.5 mph without the prop cavitating. However any further trimming up results in porpoiseing if the water is anything but glass. That is running a 15 pitch 4 blade Solas with full fuel/gear but no water in the forward tank. This particular Permatrim is one that is mounted underneath the cavitation plate. I had to take a hacksaw to a small portion of the motor trim zinc so the Permatrim would clear it and mount flush to the cavitation plate.
I actually turned around a few times (against Cindie's wishes) to get waves on the beam and following and did notice the bow steering you mention. I wanted to feel it for myself and feel it I did although it wasn't much more than I noticed with tabs fully down before. That was all with the Portland Pudgy and electric outboard on the roof and I can't say I felt any handling difference from weight on the roof. I think the extra 200lbs of batteries on the cabin floor help out a little.