Any downside to a 4 blade prop?

[jonny rotten]

Looking at a 14.50 x 18P 4 blade quicksilver Aluminum prop I can get a good deal on.I never ran a 4 blade Prop.I almost never get to WOT while cruising. Usually tool around at 3/4 throttle. No skiing. I know Ill get out of the hole better and heard it might help with vibrations which is a plus. Would this be a good choice if the price was right?
1990 4.3 alpha 1
1990 19 FT glastron 199 sierra Cuddy 2400 #'s
Running a 14.25 x 21 3 blade now.Someone told me I "may" be overproped
Was out yesterday and WOT was 4000 to 4200,not sure if my worn down prop from bottoming out on a sand bar is the reason for low WOT. I should be 4400 to 4800

 

[littlerayray]

I wouldn't drop to an 18 p I would drop down to at most 19

 

[littlerayray]

What was your top speed at wot you when you were out

 

[jonny rotten]

Not sure of the speed,next time ill use gps. Why would you not go lower than a 19? Would an 18 make the boat "piggish"? "if" I was over pitched at 21,wouldnt that bring me down to a 19 on a 3 blade,therefore an 18 on a 4 blade? Ive been looking at the online prop charts and theres a ton that are being listed as working. Ive made a few phone calls giving my boat info.Some say Im overpitched some say not.Some say 14 x 20,some say 14.5 x 18..So Im at a loss as to what to do without spending money on 5 different props I cant return

 

[littlerayray]

I don't think your over propped I think there's something else wrong your boat should handle a 21p no problem did you weigh the boat at a scale or is that what the specs say

 

[Taciturn]

I noticed a big difference in vibration dampening with the 4 blade. I went down to a 16 pitch and my wot was 4800. It also depends on your elevation. I run a 21 at lower elevation and a 19 in higher elevation when not pulling wakeboarders and tubes. I might take my 16 back and see what the 18 feels like as the 16 sure did guzzle the gas. My boat is barely bigger than yours. 1998 5.0 alpha one 21'. Sounds like the 18 would bring your wot into the rpm range you need to be in.

 

[flipbro]

You need to post this in the prop section of the forum. Those guys will get you on track...

 

[smokeonthewater]

Go get it... I think you'd be very happy with it.

Just based on current prop, rpm's, and stated use it sounds like the perfect prop for you.

 

[jonny rotten]

Yea Ill go for it.I have a feeling Ill be a little under propped but a new oem prop for $100 out the door I could always sell it without taking a beating.I called a few glastron dealers.They said most boats with a 4.3 leave with a 19 Prop.So I should be close.Im curios if Ill have a smoother ride

 

[fishrdan]

They said most boats with a 4.3 leave with a 19 Prop.

An 18P 4-blade will run about the same RPM as a 19P 3-blade, and if you're not looking at top end speed, it's a good choice. I'm running a 18P Alpha-4 also and love the prop on my boat (MUCH different boat). I've banged the prop several times and thought "ah carp, I'm headed to the prop shop" but it's still running smooth as butter.

And for $100 out the door, it is a steal. Does that come with the hub kit too?

 

[steelespike]

Yea Ill go for it.I have a feeling Ill be a little under propped but a new oem prop for $100 out the door I could always sell it without taking a beating.I called a few glastron dealers.They said most boats with a 4.3 leave with a 19 Prop.So I should be close.Im curios if Ill have a smoother ride

Usually suggested to drop one inch going to as 4 blade your wot rpm is a little low so dropping 2 inches seems reasonable.
Your hole shot will seem amazing.It should allow you to cruise at a lower rpm with less fuss to maintain plane.Is may seem smoother and respond better around the dock. Wot speed will be reduced.

 

[smokeonthewater]

As for the boat ride such as hitting waves etc... As stated it may seem smoother because you will be able to run at a lower speed but 30 mph will feel the same as 30 mph feels now....

 

[smokeonthewater]

Actually WOT likely won't suffer and MAY even increase... Remember he's over propped now and unable to reach rated rpm.

 

[Starcraft5834]

Disadvantage of 4 blade?, to few to list...........advantages many... at most loss of 1-2mph top end....best overall prop IMHO. Ive heard that latest 4 blade designs don't lose top end...dunno..

 

[steelespike]

Check the Merc Spitfire post , may be at the top of the page.

 

[steelespike]

As for the boat ride such as hitting waves etc... As stated it may seem smoother because you will be able to run at a lower speed but 30 mph will feel the same as 30 mph feels now....

I think I mislead when I said smoother operation.
I was referring to vibration usually the 4 blade feels smoother.
I do agree it should help in adjusting for rough conditions.

 

[jonny rotten]

I think I mislead when I said smoother operation.
I was referring to vibration usually the 4 blade feels smoother.
I do agree it should help in adjusting for rough conditions.

Perfect.Theres always a chop where I boat and my 19 Ft boat aint big enough to ride over them so Im always idling back and trying to stay on plain so Im not slamming into the waves.This seems like it might fit the bill perfectly

 

[jonny rotten]

on the water now.Im a fan.Ifeel no difference in top end.Never go WOT much anyway.Major difference planing off,gets right up.Fist time ever taking specs....HIT 4400 (up 300) at WOT Trimmed up for speed at 35 mph maxed out...lowest plain was 12 mph at 2400 RPM. 22 MPH At 3000 RPM cruising speed. ..How do those numbers look?..At 4400 I'm 5 honking I could even go to a 17P but that's not happening anytime soon..

 

[smokeonthewater]

You'll LOVE it

 

[jonny rotten]

"I'm thinking" not 5 honking HaHa...AUTO CORRECT CAN'T SEE CRAP IN THE Sun