Quick prop question

[toddbrown]

I know this is not the correct ofrum but I tried the the prop forum and I guess there is not very much traffic there. Anyway, I am looking to get a 4 blade rpop and need to know the correct size as to not hurt the engine. I have the Volvo 5.0 carbed, with the SX outdrive on a 20 footer. I do mostly water sports and cruising around the lake.

 

[tommays]

Re: Quick prop question

If you wait it out for DH in the prop area he really is the expert <br /><br /><br />Its going to trial and error there is no way to be sure it will do what you want<br /><br />It pays to get friendly with a local prop shop that will let you demo props as long as your returning them in 1 piece <br /><br />if you search under member Stevens you will see how many props he tryed looking for the perfet one for his use<br /><br />tommays

 

[QC]

Re: Quick prop question

Todd,<br /><br />You need to post your WOT RPM with the current setup. It is also extremely important that the info you give (WOT RPM) is accurate and with the rest of the boat operating properly i.e. engine running correctly and the boat trimmed to the best possible top speed at that WOT. It would be best if the boat was loaded similarly to how you plan to run it, fuel, gear and people . . .<br /><br />There is no correct prop for any boat, only lots of compromises that balance your desire for hole shot (acceleration) vs. top speed.

 

[toddbrown]

Re: Quick prop question

good point. the WOT is 4800 rpm. I don't mind to take a loss on the top end since I mostly do water sports. I never run anywhere near WOT whne boating. I think the most I ran was 3700 rpm and only for a short time. I normally star around 3000

 

[QC]

Re: Quick prop question

With what current prop? Dimensions? Is it in good shape? Sounds like you want better hole shot, but I still am not clear why you want to go to the 4 blade. Are you looking for a spare, or do you want better performance than you currently have?

 

[toddbrown]

Re: Quick prop question

Well, the 4 blade Propulse that I had on my 18.5 footer was really nice. I replaced my alum 3 blade and the 4 blade was smoother and had better hole shot. Lost a little on the high end but no big deal. Current 3 blade is in perfect shape, but I will use it as teh spare. for water sports, I think 4 blades are better... maybe not..

 

[QC]

Re: Quick prop question

Todd,<br /><br />You should prolly post all of the pertinent info from this thread over to the Prop Forum. You must include the pitch of the prop you are currently running for anyone to guide you on the proper pitch for a 4 blade. Check out the Steven's thread mentioned by tommays. He has been through all of this and has posted good data and info.