I am a new member with a 1995 GRADY 272 Sail Fish with the step hull configuration. I just replaced the old OX66 200's with 0 factory rebuilt 0 hour 200 HPDIs. The boat is now about 9 + miles per hour faster. When I give the engines fuel quickly the bow comes up high and stays up for for 15 to 20 seconds before the boat starts to level off and have the bow come down and the boat establish a good planing attitude. Does anyone have experience with Sting Ray fins that are attached to the cavitation plates on the twin engines? Thanks Marty
Adding Sting Ray fins to 200 hp HPDI Grady 272
- Thread starter Marty grady 272
- Start date
Have you tryed using your trim tabs? My boat does about the same thing, i just adjust the trim tabs and the engine trim.
Shouldn't need to add those monsters to your engines.
Don't trim the engines up until after the boat lifts up on plane. Keep them "tucked in" initially.
And, as noted above, use your trim tabs as needed to get the bow down.
But I'll bet on the engine trim.
Brian
Don't trim the engines up until after the boat lifts up on plane. Keep them "tucked in" initially.
And, as noted above, use your trim tabs as needed to get the bow down.
But I'll bet on the engine trim.
Brian
Check out the PERMATRIM product. They work exceedingly well. Andy at SIM is the North American importer.
http://www.permatrims.com/
Looks like Andy has a new site for the product here in the US now.
I run one with bennett tabs, they do different things, complimenting each other.
http://www.permatrims.com/
Looks like Andy has a new site for the product here in the US now.
I run one with bennett tabs, they do different things, complimenting each other.
The boat does trim up with the engin trim and the trim tabs, but it takes 15 to 20 seconds to start to bring the bow down. My real question is will the Sting Ray fins help to trim the boat quicker or keep the stern from digging in so deeply? I can't see over the bow when the bow is so high. Marty
Guys I know who have them have seen a slightly quicker time to plane on bigger boats, and a little less trim climb when getting on plane, but on bigger boats you will not see an improvement on fuel economy by much except at lower speeds where the boat used to plow and now you can plane out, might gain maybe a 3mph range down low where you plowed before and can now hold plane. You will still have a big trim, but might be able to decrease it by 2 degrees roughly by adding these. Typically you can do the same thing with your tabs, also put your engines lower when coming onto plane them trim them out for running, my boat climbs and has a big trim angle coming on plane if I have the engines trimmed for running, if I put them down I do not get it and come on plane easier, but then I trim them out for best economy once on plane if covering enough groud to be worth it.
Only thing to watch out, typically the second you fasten those foils on you void any warranty the engine has, depending on the dealer they may over look it, but there are many that will blame that and say it voided the warranty, I believe it does state it in many engine warrantiess that any modifications void it and this would clearly fit that. I know it is a rebuild, but typically they have a 1 year warranty so it may warrant waiting a year and looking into playing with the trim tabs before spending the money that might not be needed and would void your warranty before it is up.
Only thing to watch out, typically the second you fasten those foils on you void any warranty the engine has, depending on the dealer they may over look it, but there are many that will blame that and say it voided the warranty, I believe it does state it in many engine warrantiess that any modifications void it and this would clearly fit that. I know it is a rebuild, but typically they have a 1 year warranty so it may warrant waiting a year and looking into playing with the trim tabs before spending the money that might not be needed and would void your warranty before it is up.
Marty said:
Marty are you saying that when you first start off your engines are tucked all the way in to the transome with zero trim? If not then that is how you should be starting off. You could also give some bow down on the tabs at the same time right before you launch. I can't really see any reason for you having this problem with these motors.
Good luck and let us know how you make out.
gradyfish22 said:
On any boat. I had one on a 15' RIB. The boat was almost unmanagable without one, was fantastic. I think it was actually the sharkfin brand one.
The permatrim simply directs the flow of the thrust, so trim is accentuated. It helps bow down tremendously, and lifts the stern. Since it has not 'foil' it does not affect top speed. The OP obviously didn't take the link and read about the product. There is also a whole forum on THT for the Permatrim. It's also very strong because it's steel, so it even doubles as an underwater step. At first I was skeptical, but having run it for 3 years I can say it's a wonderful add-on, performs as claimed.
If I trim the motor down I get no bow-rise, and the boat will plane flat at 7-8mph with tabs and trim. Of course it's pushing bow water, but you have very positive trim control with a fin and tabs. Niether on their own will do what both in unison will do. I almost only use the tabs for side-to-side trim unless I'm cruising at a very slow speed and want to put the bow down, then the tabs are trimmed down. I do not use them for getting up on plane.
gradyfish22 said:
Do you have any anecdotal experience of this? Any specific examples of someone with a denied warranty claim because he installed a sharkfin or a permatrim?
I believe this is what you want
I put the newer XRIII Sting Ray on my HPDI and it has made all the difference in the world. We don’t have trim tabs and now I’m very reluctant to add them as she plains immediately and at lower rpms. You won’t believe it, but as advertised, we did gain a little at the top-end as well. Of course the ability to lift the bow in following seas and stick her into a head wind is awesome. She surfs a lot better too in flowing seas with the fin. Another bonus is it REQUIRES NO DRILLING HOLES! It uses the zinc bolt and clamp down screws on either side at the front. It has held tight for over a year now and a lot of use. It looks cool too, and the color match to our 2001 HPDI is uncanny. Another surprise.
http://www.marine-dynamics.com/
XRIII pictured on their home page.
Their customer service is great too. I lost one of the little plastic oval tabs that cover the clamp screws, and they sent me a few replacements in the mail immediately.
One negative is that my 16" prop clears it by a few hairs....
But, we're very happy with this improvment to our baby, and I’ll try and fandangle some images someday soon of it in action.
All the best!
Jim
I put the newer XRIII Sting Ray on my HPDI and it has made all the difference in the world. We don’t have trim tabs and now I’m very reluctant to add them as she plains immediately and at lower rpms. You won’t believe it, but as advertised, we did gain a little at the top-end as well. Of course the ability to lift the bow in following seas and stick her into a head wind is awesome. She surfs a lot better too in flowing seas with the fin. Another bonus is it REQUIRES NO DRILLING HOLES! It uses the zinc bolt and clamp down screws on either side at the front. It has held tight for over a year now and a lot of use. It looks cool too, and the color match to our 2001 HPDI is uncanny. Another surprise.
http://www.marine-dynamics.com/
XRIII pictured on their home page.
Their customer service is great too. I lost one of the little plastic oval tabs that cover the clamp screws, and they sent me a few replacements in the mail immediately.
One negative is that my 16" prop clears it by a few hairs....
But, we're very happy with this improvment to our baby, and I’ll try and fandangle some images someday soon of it in action.
All the best!
Jim