Seal of vent-holes on Turbo 1 propp

[JARB]

Tested a Yamaha Reliance 13,75 X 19 today on my Yamaha F150. Normally run a Turbo 1 14,25 X 19. One thing that surprised me was that these two visually quite different props performed almost the same on my boat. Same top-speed 49 mph, same WOT 5900 rpm, same fuel consumption and rpms at typical cruising speeds for me 28-38 mph, same hole shot times. Maybe the T1 was a bit lower on fuel at cruising and maybe the Reliance had a bit faster hole shot but that is both within the margin of error. The Reliance had a smoother sound from the engine at very low planning speeds.

When I first run the Reliance without a timer I was convinced the Reliance was slower out of the hole due to a smoother and more quieter acceleration than with the T1. But the timer showed that they were equally fast or the Reliance maybe a tad faster.

The Reliance have no vent holes but the T1 has. I suspect that the smoother low speed planning speeds and smoother acceleration of the Reliance is beacuse it lacks the vent holes. I now want to seal off the vent holes of the T1 to see what happens.

So long story, short question. How do I seal off the vent holes? I am interested in a quick way for testing and a more permanent way if it shows to be a good thing to do.

 

[NHGuy]

Re: Seal of vent-holes on Turbo 1 propp

If you can access the inside of the holes put through some plastic nail shaped plugs from the inside. Centrifugal force will keep them in place. The only thing I can think of that's the approximate shape is those little plug clips that are used to hold the cladding on under the hoods on cars. Problem there is they are too long so you'd have to cut them to length, maybe silicon em in.
Or, here's a novel idea. Some of those props have plugs made to fit them, check the manufacturers web site. Maybe they make your size. Maybe the plugs from some other brand could be "improved" to fit your holes. Or maybe a prop shop might have an opinion.

 

[wisebob]

Re: Seal of vent-holes on Turbo 1 propp

Try using some removeable 3M 4200. I just plugged the vent holes on my Stiletto Bay Pro prop to test and it seems to hold well. Put some in the hole, scrape it flat, and then cleanup the surroundings to make it really nice using mineral spirits.

I was having issues with my Bay Pro prop on my F115 whereby it would take forever to get on plane and when it did, it would only run super smooth after I hit 20 mph. The RPMs also dropped once I hit 20 mph from 4700 to like 4000. Also couldn't achieve efficient plane below 4000 rpm.

I was hoping it was because of over ventilation so plugged them up. Tried the prop out again yesterday and it was a night and day difference! It is 300% better now. The hole shot is great and I can now plane around 3500-3700 RPM.

No wonder Mercury did their PVS system. Vent holes really significantly impact performance.

I'll leave the 4200 on until it comes off but so far so good.

bob

 

[JARB]

Re: Seal of vent-holes on Turbo 1 propp

Thanks for Your answers! For testing I have decided to use wisebobs method. If the weather permits I will be testing it tomorrow. Will report the results.

 

[JARB]

Re: Seal of vent-holes on Turbo 1 propp

Tested today. The Turbo 1 is now as smooth at low speeds as the Reliance so plugging the vent-holes was good. The sealant stayed in place dispite some WOT running. Sadly the speedo got clogged so I couldnt check the hole-shot but it didnt feel slower anyway.