Prop information

[Ted S.]

I currently am running a 12 3/4" X 21" 3 blade stainless prop on my 69 Sea Ray SRV 160 with a 71 125 Johnny (140 compression). I'm getting 48 mph at 5600 rpm. A guy I know has a 14" X 18" aluminum that he said I could try out if I wanted. What type of performance changes could I expect from this prop? Right now my hole shot is pretty good, but a little sluggish if you load it down a bit. Otherwise the motor performs great, starts good and has lots of top end. thanks for the info

 

[S.T. Marine]

Re: Prop information

You will get out of the hole a little faster with a larger diamater propeller. Top end will be slower becasue you have a smaller pitch and the propeller is aluminum.. more performance with a stainless but dont hit anything with a stainless prop or you will do damage to lower not the propeller.

 

[cmjust0]

Re: Prop information

If you're running 5600RPM at WOT, I'd say you're doing OK.. The rule of thumb is that for every 1" of pitch you drop off your prop, you gain 200 RPM.. That 18 pitch prop would put you around 6200RPM at WOT, which seems really high to me.. Just my $.02, I could be wrong! Good luck!

 

[Ted S.]

Re: Prop information

Thanks guys. I'll try it out this weekend and see what happens

 

[JB]

Re: Prop information

Not a good idea, Tedinator.<br /><br />You are turning 5600 now. That is a good top end for your Johnny. If you drop 3" of pitch you will be over-revving your engine.<br /><br />Good luck.

 

[Ted S.]

Re: Prop information

Update!! I spent about an hour on the prop on friday just to clean up any nicks and imperfections, only to touch down on a submerged rock wall at the launch 30 seconds after it was in the water! The water level has dropped about 6" since I took her out last week. Not much damage, dinged one blade slightly on the leading edge but managed to straighten it out. Looks like it will need a refurbish at the end of the season Oh well, its only money!!