Prop Pitch Question for 4.3L Volvo

I have a 97 Larson Flyer 17' runabout. I just bought it last week and have a couple questions about the prop. It has a 21 pitch prop on it right now. I think that the RPM's should stay @ 4800 or below. I am getting 5k solid at WOT. Is this safe?!? I wouldn;t mind a 19 pitch to get a little better holeshot. The holeshot is good now but i feel it could be better with a 19P but i fear over revving. Is this a valid concern or am i being too cautious? LMK as i am new to boating. Thanks in advance for your help.

Re: Prop Pitch Question for 4.3L Volvo

Forgot to state that it is a 19P Aluminum 3 blade prop. Sorry

Re: Prop Pitch Question for 4.3L Volvo

Your gonna overrev about another 3-400 rpm with a lower pitch prop.

Re: Prop Pitch Question for 4.3L Volvo

If you want better hole shot and stay close to your present rpm a 4 blade Solas Amita in a 20' pitch should put you close to your present rpm and imprive hole shot and stay on plane with less power.It may lower your top speed slightly.

Re: Prop Pitch Question for 4.3L Volvo

steelespike said:

If you want better hole shot and stay close to your present rpm a 4 blade Solas Amita in a 20' pitch should put you close to your present rpm and imprive hole shot and stay on plane with less power.It may lower your top speed slightly.

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Is this an Aluminum prop or Stainless?
I was told to stay aluminum to reduce chances of Lower Unit impact damage as aluminum will break/chip as to where Stainless will not thus damaging the lower unit. Is this true? Or was i fed a line of poop.

Re: Prop Pitch Question for 4.3L Volvo

Would a 21P 4 blade Aluminum prop make a noticeable difference in comparison to the 21P 3 blade Aluminum one that i currently have? Just trrying to get a grasp on this, It is the first boat i have owned with power at all and i want to get the most out of it for my needs. Top speed isn't everything, need a good holeshot but don't want to have to worry about over revving it.

Anyone have an answer as to whether or not the 5K rpm's i am getting not is ok? or am o revving too high as it is?

Re: Prop Pitch Question for 4.3L Volvo

Anyone?!?!

Re: Prop Pitch Question for 4.3L Volvo

All I can tell you is what I did on a similar setup. '07 4.3L VP 18.5'. Had a AL 21P 3 blade prop. Got up to 4800k RPM and 47ish mph OK holeshot but wanted better so went to a SS 4blade 19P and hit about the same top end (w/i 1mph) with a much better holeshot. I can get 5k rpm out of it with just a "normal" load but try not to go above 4600 rpm since that's my listed WOT. I figure this is good so when I do have a heavier load, I have the power to still get the most demanding skier up.

Thought about getting a 21p 3 blade SS prop or even trying a 23p so when I feel like hitting it fast, I can.

I don't worry so much about the aluminum vs. SS damage issue. There are opinions both ways. I keep the 21p AL for when I'm in areas I don't know very well just in case. My Solas has a nice rubber hub that's supposed to really help when you do hit something. I actually did "test" it once and all was good.

Re: Prop Pitch Question for 4.3L Volvo

Wired--> Appreciate the input.

I am going to go with a 21P 4blade Alum and see how it goes for me. The boat is a 17" fairly shallow hull boat so it already gets up pretty good. Just looking for a little better. Don't want to go down to a 19P as I fear over revving. Thanks everyone.

When i get the funds to get it and put it on, I will try it and report the results. Hoping i like the difference.

Re: Prop Pitch Question for 4.3L Volvo

I have a what I would think is a similar drive train, 1997 volvo 4.3 but could be geared differently to yours (1.66 sx drive). I had a 3 blade 23p that was sluggish holeshot but ran 46 mph. Changed for 23p mercury high five and holeshot is great and still get same top speed. Max rpms on factory tacho are around 4600-4700 which I believe is pretty much spot on. It also now has a tower, speakers, amps etc which add a fair bit of additional weight. The way the 5 blader holds the speed in the corners is the best thing and I would think the 4 blade would be something similar.
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Re: Prop Pitch Question for 4.3L Volvo

I am not sure about the ratio on my lower unit. It is a cobra sx i believe. How do i find out what the ratio is?

My top speed right now with the 21P Alum 3 blade is 52mph and RPM's are @ 4900-5000 WOT.

Hoping that the 4 blade slows down the RPM's a little, even if i do lose top end as 52 is pretty quick as it is.

Appreciate the replies and input.

Re: Prop Pitch Question for 4.3L Volvo

+1 on th 4 blade. I just put one on. 21p alum. Works great for my 4.3 volvo (Larson 18 ft)