Dhadley, question on your X dimension

[Bry21317]

I have read quite a few posts where the key thing that you talk about is raising the motor to get more RPM's. Or changing the X dimension, which seems to be related to the Raising the motor. <br /><br />Could you please describe how high the motor should be, and what would signs to look for if you would need to raise it? Also, isn't kinda hard to move the motor up on the transom, unless you have a jack plate?<br /><br />Just wondering. I love all your input and always read it.<br /><br />Thanks,<br />Bryan Cox

 

[Dhadley]

Re: Dhadley, question on your X dimension

Thanks Bryan.<br /><br />Yes it is easier to move a motor with a jackplate but every motor has a variety of holes for adjustment, although it is not very much.<br /><br />X dimension (motor height) is a marriage of hull design (potiental), prop design and gearcase shape. I think you can see where this is going. It wouldn't do any good to put my 700.00 Mazco prop on my Aquasport even with a jackplate. And my Hydrostream or Mirage wouldn't work very well with even the best Stiletto or Turbo. <br /><br />What we look at on a given rig is the baseline and what the owner is looking for. We dont set up the Offshore boat the same as the Drag boat or something for skiing. Then you determine (through testing) whats holding it back. It may be that the rig has 35% slip. We then work on reducing that slip percentage or drag. The more you hide the gearcase behind the transom the less drag you have. Obviously not many props will work that high and not many hulls will respond to that. Props have different amounts of "lift" which reduces drag or "wetted surface". This is all part of why we talk about where the centerline of the propshaft is in relation to the "true" bottom of the hull. <br /><br />On my Aquasport the motor is only raised slightly but on my Hydrostream the propshaft is just below the bottom of the pad. On the Mirage the propshaft is above the pad on the center pod. <br /><br />Long before you get that high you have to deal with water pick up. And steering torque. Its not unusual for todays props to "hook up" higher than a stock gearcase was designed to run at. Then we get into gearcase shape.<br /><br />I know this is pretty long but thats only the surface of the idea. <br /><br />Tell us about your rig and set up. Its always fun to see what other folks have.<br /><br />Good luck!

 

[Spidybot]

Re: Dhadley, question on your X dimension

Thanks Dhadley!<br /><br />Some thinks they know all b'cause they've been along for many years.<br /><br />Your input enphasizes how each setup calls for it's own considerations and that many are not conform to traditional designs. <br /><br />Pointing out a specific prop for somebody's use is not simple... best we can do is try.

 

[Dhadley]

Re: Dhadley, question on your X dimension

And try and try and.............Lol!<br /><br />I have been involved with this Hydrostream since 1985 when it was new. I finally got a chance to buy it a year ago and I am still trying things! None of which have to do with the powerhead!<br /><br />But its a sweet ride. And room for 5.

 

[Bry21317]

Re: Dhadley, question on your X dimension

Dhadley,<br />My Setup is a Bayliner, hows that. lol. I know but actually I love this obat now. I have redone the interior to the way that I wanted it, Redid the entire floor, with alot of Fiberglass and resin so it will never get soft again, of course replacing the bad wood at the time. Recarpeted it. Redid all the guages and everything and now I love it.<br /><br />The engine is the old Force 125, that seems to be running better than it ever did in the five years I've had it. But I'm meticulous on that engine about fixing it before something does mess up. The last piece I have to get fixed is the Trim Pump it has some stripped threads where the lines go in, so the machine shop is going to drill them out and put some brass fittings in for my lines to go into.<br /><br />Boat is 1988 Bayliner Capri 19 Foot Open Bow<br />Prop- Hustler 13 1/4 X 17 pitch prop -Love this<br />Boeyson Reeds<br />NGK Plugs<br />NGK Screw on Spark Plug Caps<br />Carbs cleaned and synced as good as they can be<br />New Fuel Diaphragm<br /><br />Timing needs to be double checked, but I think its set at 30 or 32, but I just found I think its supposed to be set at 28, what difference woudl this make?<br /><br />Boat will run 5000 RPM's and just over 40mph by Garmin GPS 12<br /><br />I do all the work, its like a hobbie to me. I have a buddies old Merc 115 Inline 6 all torn apart in my garage waiting for the pistons to rebuild that, so we can make his little boat scream. Also have another buddies Crestliner 19 Foot old boat, with a reinforced transom and Johnson 200 in my driveway that we are working on today. This boat will straight fly. But it has no spark, but on one cylinder.<br /><br />Now you see my setup, and what I like to do. I love to fix things, I guess thats why I do tech support for computer company. lol<br /><br />Ill try to get some pics of My boat up here somewhere. How I did the inside, it sure doesn't look like a bayliner, inside anymore.<br /><br />Thanks,<br />Bryan Cox

 

[Dhadley]

Re: Dhadley, question on your X dimension

I would stick with the stock timing unless the Force experts say different. Too much lead time will burn a piston. Is that the RPM's you are looking for? Look in your service manual and get me the gear ratio and we'll figure out your slip %.<br /><br />Sounds like a fun deal. I like doing my own work too. That way I already know the customer is a jerk. Lol!<br /><br />Good luck!

 

[Bry21317]

Re: Dhadley, question on your X dimension

Ok,<br />Give me 5 and I will have it for you.<br /><br />I haven't run it yet on the lake with the new Diaphragm in the fuel pump, the other one was a little stretched.<br /><br />Thanks,<br />Bryan Cox

 

[Bry21317]

Re: Dhadley, question on your X dimension

The manual says that this egnine's gear ratio is:<br /><br />1.73:1 Tooth Count: 15:26<br /><br />This is greek to me so far. It will mean something to you I'm sure.<br /><br />Thanks for all the help,<br />Bryan Cox

 

[Dhadley]

Re: Dhadley, question on your X dimension

You are right at 11% slip. Thats not bad at all!<br /><br />I'm sure you thought of it already but you might raise the motor a little and see what happens with the speed vs RPM. <br /><br />Very interesting!

 

[Bry21317]

Re: Dhadley, question on your X dimension

I guess that is good then. I'm glad. So could the timing be keeping me from getting up to the 5500 rpm's, if I have it set at 30, when it should be at 28BTDC? Of if I drop to a 15 Pitch prop, this would give me more RPM's, but would I lose mouch on the speed?<br /><br />Sorry to pick your brain so much, but I am trying everything I can think of.<br /><br />I did look at my motor last night. The Engine is mounted on the Transom with the caviatation plate even with the very tip of the V. It seemed to line up about perfect. There are 4 bolts in the engine and I looked at the way they drilled the holes, there are 4 sets of extra holes on the bracket, but the way the holes were drilled they used the very bottom holes and the very top holes. So there is no way that I could just move it up and it line up with the other set of holes, to move the engine up on the transom easy.<br /><br />Thanks for all your help,<br />Bryan Cox

 

[Dhadley]

Re: Dhadley, question on your X dimension

If you have the timing at 30 now and back off to 28 you may see a small decrease in RPM. If you go to a 15" prop it should help the holeshot but most likely hurt top end.<br /><br />Its a shame they didnt use a standard template to drill the holes to mount the motor. I know it would be a pain but I would drill 2 more holes wherever needed so that the bolts would all be in the top holes and fill the other 2. That way you could raise the motor and put it back if needed.<br /><br />Let us know!

 

[Bry21317]

Re: Dhadley, question on your X dimension

The Hole shot is awesome now with this Huslter 17 Pitch Prop. I love this Prop. I could try to get a 15 Pitch and try that to see what happens.<br /><br />Someone had posted about a bulletin for this engine that it should be set to 32 now, instead of the 28 if you run the 89 octane gas in it instead of 87.<br /><br />I'll try to get the trim pump fixed asap so I can get back on the water to tes what the fuel pump rebuild has done.<br /><br />Thanks for everything,<br />Bryan Cox