Prop Talk

[cpropes2005]

I currently have an ACME 911 (13 x 10.5) on my boat but my dealer is recommending I go up to a 13.5 x 13. I have been having a few mechanical issues that are hopefully resolved now but they said that part of the reason could be that the engine is revving too high. I could see that being true if we ran wide open all of the time but If I am not surfing or wakeboarding we typically dont cruise around much faster than about 30mph and with the 911 I have never noticed the RPM's being abnormally high at that speed. I can still easily get 40+ mph with that prop. Thoughts on keeping what I have vs swapping to a 13.5 x 13? 03 22V, 380hp 6L with 1:1 v-drive.

[Ruger761]

Im no prop expert but what RPMs are they saying is too high, what RPM are you at boarding, and what rpm at 40mph? Unless really high rpm my personal though if you can still hit 40mph Id say your current prop is ok. Others on here know a lot more than I do. Or give Acme a call and see what their sales team says.

[cpropes2005]

I have never payed particular attention to my exact RPM's at different speeds but they never seemed unusually high to me. I will get more exact numbers when I go out this weekend. It sounded like when they ran it wide open (they were lake testing it for me for my other mechanical issues) it was hitting the rev limiter which they said a proper sized prop shouldn't ever do. That is probably true but I dont really like to run wide open anyways so I am thinking I might be fine with what I have.

[Ruger761]

Id say on a normal bass boat or similar Id agree with them it prob shouldnt hit the rev limiter, but a boat that is built for surfing or boarding with heavy ballast is more than likely going to hit it. Its up to the driver to make sure it doesnt get over rev'd. Personally it would have p*ssed me off to have a mechanic knowingly bounce it off the rev limiter when he should know what the higher RPM limit of the motor is anyways and should have been watching it. Almost like they were on more of a joy ride vs a test drive not paying attention to what they were doing.

[Wickedcummins]

size matters lol. go bigger

[NICKYPOO]

I'm in favor of not hitting the limiter. I like having it propped to just below the limiter with normal crew and gear. I actually have another almost 200 rpm I could use but, its close enough for now. I would have to jump it to spin it. If your running a ton of ballast though, it might be something you have to risk. I'm with you on the fact that I rarely run WOT. I have been know to take a pass down our local liquid quarter mile though.

IMO, given that fact your mechanic took it out and bounced it off the limiter, I would call Acme. If you want a little more top end, they will tell you what prop and what it should do performance wise. They will also tell you what that 13 1/2x 13 will do if you have a part number of them.

[Wickedcummins]

Id run a 1235 on that sucka.. Killer prop and it gets r done

[cpropes2005]

I will do some more testing with ballast and people to see what it would typically be like for me and then give acme a call. I pulled most of the gear out of the boat before I took it in so I think their water test was probably just the mechanic and about half a tank of gas so that may be part of the reason he was able to hit the rev limiter. They also said on the 2nd water test they put a 13 x 16 which is what comes stock on their new boats and it seemed like too high of a pitch but he said it ran 54mph with that prop. I think the 13 1/2 x 13 recomendation is probably reasonable for an all around prop but if I can keep my awesome hole shot and not have to drop the $ for a new prop that would be ideal. Like mentioned above I am typically the only one who drives my boat and I am certainly the only one who would be running it WOT and I fell like I can keep it out of the rev limiter as a driver.

[cpropes2005]

ACME website says 1235 is a 14.5 x 14.25. I am not sure I have enough clearance for that big of a prop and that would be a big jump to a 14.25 pitch all the way from the 10.5 I have now.

[Wickedcummins]

I had a 03 22v and it fit on mine with room.

[cpropes2005]

Anybody know if a prop shop can bore out the shaft diameter on a prop? I actually have a 13.5 x 13 3 blade from my old Supra but the shaft diameter is 1" instead of 1 1/8". I doubt it is possible since it is a tapered hole with a key way but I figure it couldn't hurt to ask.

[WakerideN]

acme 1433 would be my take on it... if your wanting better hole shot... and not as big as a 1235 .50 smaller... my

[cpropes2005]

Thats interesting on the 1235. I may have more room than I thought. I havent measured it just basing it on what I remember it looking like. I also think my prop already gets pretty close to the trailer so I will have to check that out too.

[Wickedcummins]

[Wickedcummins]

This will also help you make a good choice

http://www.csgnetwork.com/marinepropcalc.html