which prop for best perf?

[dreamchaser]

Looking to purchase a new ss prop for best perf that does not give a lot of bow lift . Looking in the range of 19 to 21p ,,,also 1 that will provide stern lift if there is such a thing? ...1983 evirude 115 ,,,any sugg. ? thks

 

[walleyehed]

Re: which prop for best perf?

What prop, model and size, are you using now, and what is it doing or not doing?
Also list WOT RPM with that prop with your normal load.

 

[dreamchaser]

Re: which prop for best perf?

Thks Kenny...... The prop im using now is a OMC Aluminum 176215 RE ;14x19p .. but it has been repitched to a 21..which is what is stamped on it now .The rpm is in the right range 5500 ......."doin or not doin" ....just looking for better perf and not bow lift , have motor now mounted in second from bottom hole . any ideas for less bow lift and overall grip and speed? thku. Leo

 

[walleyehed]

Re: which prop for best perf?

well, #1., it depends on what they done to the 19 to make it a 21.
Also, that prop is/was an over-all lifter, so I have to ask what is taking place to make you want less bow-lift, yet higher performance?
That '83 115 needs about 200-300 more RPM to be in the "zone"...no, that's not what the manual says, but we don't have 1983 quality fuel either.

 

[dreamchaser]

Re: which prop for best perf?

Kenny...dont know what was done to repitch as i bought it from the prop shop that way. The boat has a porpoising issue as power increases to near wot ..was wondering if a sternlifter prop might help to blanace the light weight of the bow and be a high performance prop at the same time ......."in a perfect world?" thks ....Leo

 

[walleyehed]

Re: which prop for best perf?

Well, if we "assume" the shop done a decent job on the prop, they may have changed the cup, in effect, changing the parabolic Rake.
Sometimes, having too much weight in the rear will move the CG back far enough to cause this problem as well.
So, if your load configuration cannot be changed, we may need to look at something in the "over-all" lifting designs.
Do you have any set-back, or is the engine mounted direct to the transom?
What prop were you running before purchasing this 19 into a 21 prop?

 

[dreamchaser]

Re: which prop for best perf?

test......

 

[dreamchaser]

Re: which prop for best perf?

Kenny .ur dead on right with the CG being to stern. I do have smart tabs installed and have been toying with them as well ...........I think I can dial em in a little better yet........There is no setback on this boat ....i have tried a OMC SST 389948 17P....this prop i can wind out to 6600rpm .to much......btw there is some pics of my boat in the "gen boatin disscussions.....".issues issues issues"Waiting for ur ideas just lookin at diff options for perf and lift..thku......Leo

 

[dreamchaser]

Re: which prop for best perf?

Correction......... Kenny the pics are in Prop ques and topics "issues issues issues"

 

[walleyehed]

Re: which prop for best perf?

Disconnect the smart-tabs from the top bracket and tie up the cylinders and test-run to see if it stays the same, better or worse.

 

[dreamchaser]

Re: which prop for best perf?

thks Kenny for ur time...wil do !!!!!!... "i wish i could leave em disconnected as they do grab a lot of water......but im willing to do anything to get this boat of mine set up right .... will post results soon .

 

[dreamchaser]

Re: which prop for best perf?

Kenny....... disconnected the tabs same problem boat starts to porpoise near wot ....worse. ....The Local shop here has a omc part no. 389510 ,,its stamped 14x19p.I noticed that the cupping comes right out to the end of the blade tip.... the shop told me it is"double cupped" I can trial run this prop ....any more ideas suggestions much appreciated....thks ...leo

 

[walleyehed]

Re: which prop for best perf?

I'd say try any prop you can test, but I think you need a stern-lifter.

 

[dreamchaser]

Re: which prop for best perf?

Thks kenny... been doin some research on double cupped props ..going to try it soon as it warms up here a bit ....as far as stern lifters go any suggestions ? thks

 

[walleyehed]

Re: which prop for best perf?

I would think a std SST OMC would work pretty good...the SSTII had more bow lift.
The Stiletto Bay Pro 4 series 1 may not be a bad choice..it's an over-all lifter and this prop tends to lift the stern a bit more than a 3-bld.

 

[dreamchaser]

Re: which prop for best perf?

Kenny....Thks for ur patience ,, going to go prop shopping, and try the 389510 as well...will post results as they come in....... thks again leo