Dr. Walleyedhead and Professor Dhaley

[--GQ--]

Here is the deal. My old prop.(aluminum 3 blades 14.5 x 19p). Fully loaded 40mph WOT at 5000rpm. Holeshot was terrible. Replaced with a 4 blades adjustable prop adjusted to 22p. Fully loaded, holeshot is way better, but top speed remains the same as the aluminum prop. Inaddition WOT is now 4200. I guess nothing is free.<br /><br />I saw the video of the Torque-Shift Prop someone posted this morning. I would like to try it out. What say you?<br /><br />engine: 4 cylinders 135 hp. volvo penta.

 

[walleyehed]

Re: Dr. Walleyedhead and Professor Dhaley

First, what is the max recommended RPM for that engine set-up???<br />I do not in any way, understand why 22P would give better hole-shot than a 19P, yet pull 800RPM less at WOT...<br />Can ya fill us in with a few more details, like boat type, and the manufacturer of both props you've mentioned, please.<br />And, as your signature states "The Beach", I will assume you are running at or near sea-level..???

 

[--GQ--]

Re: Dr. Walleyedhead and Professor Dhaley

boat 180 ssi 05<br />engine 4 cycl. 135hp<br /><br />stock prop = 3 blades 19p......top speed=40mph @ 5000rpm<br />new prop = 4 blades 22p.....top speed=40mph @ 4200rpm

 

[Richard Petersen]

Re: Dr. Walleyedhead and Professor Dhaley

I read him as having a adjustable pitch prop. I can not tell if it is a Auto Adjust or not. Maybe a defective old prop?---------------------------------- Another thing, My 2002 186 SSI 5.0L 220hp runs a 14.25 X 21 3 blades Fact. alum. Fantastic hole, 2 sec. on plane and 56 on GPS at 4900, REV limiter cutting in. His gauges are not right?

 

[--GQ--]

Re: Dr. Walleyedhead and Professor Dhaley

Originally posted by cyclops2:<br /> I read him as having a adjustable pitch prop. I can not tell if it is a Auto Adjust or not. Maybe a defective old prop?---------------------------------- Another thing, My 2002 186 SSI 5.0L 220hp runs a 14.25 X 21 3 blades Fact. alum. Fantastic hole, 2 sec. on plane and 56 on GPS at 4900, REV limiter cutting in. His gauges are not right?

The speed was measured with a GPS 76c garmin. Propulse 4 blades adjustable prop. manually adjusted to 22p(max).

 

[walleyehed]

Re: Dr. Walleyedhead and Professor Dhaley

OK, if you have it adjusted to whatever, you need to have it set-up to achieve the Recommended WOT. The fact it runs 40 with both tells me 2 things...either the prop design is poor, or the engine is below it's torque curve and doesn't have enough umph to pull the 22 or it would be faster than the 19...<br />What is you max rec. RPM????

 

[--GQ--]

Re: Dr. Walleyedhead and Professor Dhaley

Dr. Walleyedhead, my last question was, "should I get the Torque-Shift Prop."?<br /><br />Max RPM 4600

 

[walleyehed]

Re: Dr. Walleyedhead and Professor Dhaley

I have to ask myself if I would buy one....No, personally, I wouldn't, but my application is a lighter boat with 200HP, so I don't need the transmision-like abilities of that prop.<br />I will not recommend it based on the fact I know of quite a few that have came apart or have worn out in less than 2 years.<br />For the money spent, I'd go with a high quality SS in a 3-blade that would allow the RPM at WOT and vent it for serious hole-shot.<br />Torque-shift may have it's good points, and may work fine for you, but I can't rightly recommend it.<br />I know Dhadley has seen several come apart at high-end and darn near got hit by a blade...I got a pretty good Idea what he'd say...when that blade DOES leave, very few lower units will tolerate that without some serious damage.

 

[ramster]

Re: Dr. Walleyedhead and Professor Dhaley

Cyclopes, tell me more about your boat, what brand? I have a Glastron 195 SX with a 220 HP volvo GL, and it only runs around 54 @ 4600 with the stock 14.25 X 21 AL and with a four blade Solas 21, same speed but only 4200 RPM

 

[imported_bjs]

Re: Dr. Walleyedhead and Professor Dhaley

i thought 4 blade props didnt make much top speed? its just a question.i thought 3 blades were better for top speed.

 

[walleyehed]

Re: Dr. Walleyedhead and Professor Dhaley

In most applications, 3bld IS faster...when you start getting into high-end Bassboats and racing V's the 4-5 blade props show better because only half of the prop is in the water.

 

[Texasmark]

Re: Dr. Walleyedhead and Professor Dhaley

Well Kenny,<br /><br />I might have to agree with you again - 5 blade doing better in currently designed, eleveated high perf applications........but....<br /><br />So I guess when we were kids racing our little Mercs and our teeny 2 bladed high pitched props we were heading in the wrong direction.<br /><br />Course, there is a difference. We were running light hydro's, not 20 ft bass boats....and there was no such thing as hole shots...you measured it in minutes. Grin<br /><br />I really think their purpose is to get that hole with a jacked up engine rather than cavitating yourself silly. But I don't know; haven't seen any specs on the why's they came along.<br /><br />See ya,<br /><br />Mark

 

[walleyehed]

Re: Dr. Walleyedhead and Professor Dhaley

jackplate with a 4-bld eliminates the issue of using a 4-bld just for hole-shot....you can usually set a 4 to match a 3-bld in speed, but as Ron G. found out, when you change load, adding another blade or increasing diameter isn't "always" the right answer....