Engine height w/ Permatrim
- Thread starter PhilR
- Start date
marvin4239
New member
Phil when I installed my permatrim I installed a SS prop at the same time. With the boat on the trailer I put a straight edge on the bottom of the boat and trimmed the motor down until the permatrim was parallel with the staight edge. At that point the permatrim was about 3/4" below the straight edge or bottom of the boat. I tested the boat and speed and rpm was a little slower than before installing the permatrim. I raised the motor one hole which put the permatrim about 1/4" above the bottom and the boat preforms well with no loss in speed or RPM. I don't really know if this is correct procedure but it works for me. My motor is a Suzuki 90 but I don't think that should make a difference. I've read with a SS prop you can run the motor higher.
marvin4239":tnnpfwn9 said:
That's essentially what I had on the Jenny B, albeit slightly below the hull. It also made the motor trim gauge a snap to "calibrate" afer I set the Permatrim parallel with the bottom. I had no difference in speed or economy before or after installation. Stock aluminum prop, F75 Yamahaha.
Don
After talking extensively with a Permatrim tech at Shipyard Island Marina I moved my Honda 90 up to the center hole. Now I’m able to trim the boat level at high cruise, and gain a little speed.
The underside of the Permatrim is parallel with the bottom of the boat now, but for optimum performance was told moving the motor up a little move would improve performance even more. At this higher motor location its possible an aluminum prop could cavitate, so switching to a stainless may be necessary.
But- By increasing the size of the factory cavitation plate, by up to four times. PermatrimTM reduces the chance for the propeller to create an air pocket - the cause of cavitation.
The guy I talked with at Shipyard Island marina thinks a stainless wouldn’t be necessary given the low performance characteristic and slower speeds of the C-dory.
This spring I’ll move the motor to the top hole, if cavitation occurs I’ll most likely drop it back down.
The underside of the Permatrim is parallel with the bottom of the boat now, but for optimum performance was told moving the motor up a little move would improve performance even more. At this higher motor location its possible an aluminum prop could cavitate, so switching to a stainless may be necessary.
But- By increasing the size of the factory cavitation plate, by up to four times. PermatrimTM reduces the chance for the propeller to create an air pocket - the cause of cavitation.
The guy I talked with at Shipyard Island marina thinks a stainless wouldn’t be necessary given the low performance characteristic and slower speeds of the C-dory.
This spring I’ll move the motor to the top hole, if cavitation occurs I’ll most likely drop it back down.
Our Tom cat has the Permatrims running on top of the water at planing speeds. However since the engine is on a bracket, it is set higher anyway. The C Dory 25 has the Permatrim submerged. My plan is to move the motor on the C Dory 25 up until the Permatrim is even with the bottom of the boat (it is close to 2" below the bottom. The problem is that I don't think that I have enough "hole" room to come up--and may have to redrill the holes--that means filling the old holes. So it is more complex than just moving the motor up a hole.
Jay,
I'm in the top hole on my motor with the Permatrim about 1/2 inch above the bottom of the boat when the motor is trimmed parallel to the bottom. In normal running (less than WOT) the motor is trimmed down somewhat (the front of the Permatrim is higher than the rear forcing the bow down). I have run several props ranging from 14 pitch to 17 pitch and the only prop that absolutely wouldn't work was the 17 pitch. For some reason it could not generate the same RPM as without the Permatrim by a significant amount. When I trimmed the motor way up you could feel the Permatrim rise out of the water and the motor started cavitating immediately. The 17 pitch 3 blade aluminum prop (13.25 inches in diameter) was completely useless when operating with the Permatrim installed. I tried a 4 blade 15 pitch Solas and 3 blade 15 pitch Solas and they showed some degraded performance on the top end. The 3 blade 14 pitch stainless QuickSilver prop performed the best with the Permatrim.
I'm in the top hole on my motor with the Permatrim about 1/2 inch above the bottom of the boat when the motor is trimmed parallel to the bottom. In normal running (less than WOT) the motor is trimmed down somewhat (the front of the Permatrim is higher than the rear forcing the bow down). I have run several props ranging from 14 pitch to 17 pitch and the only prop that absolutely wouldn't work was the 17 pitch. For some reason it could not generate the same RPM as without the Permatrim by a significant amount. When I trimmed the motor way up you could feel the Permatrim rise out of the water and the motor started cavitating immediately. The 17 pitch 3 blade aluminum prop (13.25 inches in diameter) was completely useless when operating with the Permatrim installed. I tried a 4 blade 15 pitch Solas and 3 blade 15 pitch Solas and they showed some degraded performance on the top end. The 3 blade 14 pitch stainless QuickSilver prop performed the best with the Permatrim.
Hi Tom,
If cavitation becomes a problem with my stock prop after I raise the motor perhaps you’d be willing to lend me that 3 blade 15 pitch stainless solas again, :wink think that’s the one. If that salves the cavitation problem maybe I’ll opt for buying the 3 blade 14 pitch stainless Quicksilver.
You’re bound and determined to sell me on that Quicksilver, maybe Cabalas is having a sale?
If cavitation becomes a problem with my stock prop after I raise the motor perhaps you’d be willing to lend me that 3 blade 15 pitch stainless solas again, :wink think that’s the one. If that salves the cavitation problem maybe I’ll opt for buying the 3 blade 14 pitch stainless Quicksilver.
You’re bound and determined to sell me on that Quicksilver, maybe Cabalas is having a sale?
Thank you all for the good info! I just checked and the top of the Permatrim on my motor is 1" below the bottom of the hull when parallel. I may try raising it one hole in the springtime. I'd like to try the Quicksilver 14 pitch ss prop....can someone give me the proper description and suggest a good place to buy it?
Phil,
I'm not sure my experience with the Quicksilver 14 pitch prop on a heavily loaded 22 will translate over to a similar experience on a 19 Angler. When I am light, I can get into the rev limiter on the motor if I trim it up too high. I chose the 14 pitch prop for low end performance and fuel economy when heavily loaded. I would think you would be better served with a 15 or 16 pitch prop on a 19.
However, if you want to try. Cabelas has it in their catalog. It's the only 14 pitch prop available for a Honda that I have seen.
I'm not sure my experience with the Quicksilver 14 pitch prop on a heavily loaded 22 will translate over to a similar experience on a 19 Angler. When I am light, I can get into the rev limiter on the motor if I trim it up too high. I chose the 14 pitch prop for low end performance and fuel economy when heavily loaded. I would think you would be better served with a 15 or 16 pitch prop on a 19.
However, if you want to try. Cabelas has it in their catalog. It's the only 14 pitch prop available for a Honda that I have seen.
Yosef
1988 22 Cruiser "Heron" Eastern Washington (state)
marvin4239":2v8a3a1c said:
I've got a 1988 22 Cruiser with a 2004 Suzuki 90HP with the Permatrim ~3/4" below the bottom of the boat running an aluminum three blade, 14" diameter, 17" pitch.
1. What stainless prop did you install?
2. Any advice on re-sealing the bolt/motor junction at the transom?
TIA,
-Joe