propellor spec information

Dick Baner · Post by **Dick Baner** » Wed Aug 17, 2011 10:07 am

Can anyone tell me what the diameter and pitch are on prop numbers 31176 (LH) and 31175 (RH). Also any opinion on whether these are appropriate to use on a 33 ft cruiser with 350 engines of 260 hp. thanks

gbraker · Post by **gbraker** » Wed Aug 17, 2011 12:24 pm

It depends on several things, such as is there gear reduction? If so what is the gear reduction?

I think the hull card would tell you how it came from the factory, but if it has been repowered you probably have to use a prop that is either larger or has more pitch, or both.

Dick Baner · Post by **Dick Baner** » Wed Aug 17, 2011 2:10 pm

Sorry, I should have included that information. The original engines were 283F and the original props according to the hull card were #1002 and 1003 which I think were 15 dia, 15 pitch 1 1/4 shaft. It has a reduction gear but the hull card does not specify the reduction ratio although I believe it is 2 to 1.

gbraker · Post by **gbraker** » Wed Aug 17, 2011 4:41 pm

I have a 30 ft Connie with 327F and it has 16/16 props, and it has reduction 1.5. Probably yours is also a 1.5 reduction.

There is no doubt that you can turn a larger prop. I don't know if you have room for a larger diameter, but I would expect you can turn a larger prop than me. There is a propeller handbook by David Gerr that might help. Sometimes its trial & error. Hopefully someone on this list will have already done it and you won't have to reinvent the wheel. Sorry about the play on words.

drrot · Post by **drrot** » Wed Aug 17, 2011 8:47 pm

Dick,
Your original post had 5 digit prop numbers. My books don't show them. Any idea what they are?

Dick Baner · Post by **Dick Baner** » Wed Aug 17, 2011 9:56 pm

Jim, they are 5 digit numbers stamped into the hub side of each prop like chris props but not stamped with the chris name like some I have seen. No brand markings of any kind. db

drrot · Post by **drrot** » Thu Aug 18, 2011 7:45 am

Owens used numbers like that. Any idea what size they are?

Dick Baner · Post by **Dick Baner** » Thu Aug 18, 2011 10:22 am

Jim, As best I can tell they are 13" diameter and figuring the pitch is beyond my ability. They came with the Seastrake as spares and seem to be smaller than what came with the 283 originally so probably way to small for the current 350's. db

gbraker · Post by **gbraker** » Thu Aug 18, 2011 10:42 am

Thirteen inch diameter is what I would expect on a direct drive with no gear reduction.

drrot · Post by **drrot** » Thu Aug 18, 2011 11:10 am

Dick,
Your boat calls for 15X15 with the 283 and 15X16 with a 327. Manual says 1.5-1 reductions. I have a pair of 15X16 if you want to try them.
JIM

gbraker · Post by **gbraker** » Thu Aug 18, 2011 11:39 am

So it went up 1 inch in pitch for the additional 25 horsepower, going from a 283 to a 327. His boat is 260 horse power with is 50 more than the 327 which has 210.

On that bases he would need a 15x18. or maybe a 16x17.

I'm just ball parking it based on what was posted.

drrot · Post by **drrot** » Thu Aug 18, 2011 12:10 pm

gbraker wrote: I'm just ball parking it based on what was posted.

I'm just offering based on what I have in stock

gbraker · Post by **gbraker** » Thu Aug 18, 2011 12:40 pm

I think they will work just fine. If they need to be repitched a good prop guy can do that within reason.

Dick Baner · Post by **Dick Baner** » Thu Aug 18, 2011 12:56 pm

Thanks for the information fellows. The props currently on the boat are at the prop shop getting straightened so I was basically curious about the spare set. I will measure the current ones and ask the prop guy what pitch those have as they seem to run the boat at the proper top speed/RPM mix.

gbraker · Post by **gbraker** » Thu Aug 18, 2011 1:10 pm

Let us know, I'm curious what the pitch & diameter is, since you have more powerful engines now.

Dick Baner · Post by **Dick Baner** » Thu Aug 18, 2011 4:55 pm

One more thing of interest. I found another single spare prop for left hand rotation and it is marked as a 16 Dia, 18 pitch and 1 1/4 shaft. That may well be a match for what is currently on the boat. With the current props the cruiser is actually faster at the top end then my 18.5 ft Carver, about 35 mph on the GPS whereas the Carver only makes about 34. db

Dick Baner · Post by **Dick Baner** » Mon Aug 22, 2011 12:24 pm

Tje now straightened props on the boat are marked as
16 diameter and 14 pitch. 14 seems pretty shallow to me but they seem to do fine on the boat so I try not to fix things that aren't broke.

gbraker · Post by **gbraker** » Mon Aug 22, 2011 2:42 pm

If you go wide open throttle, what is your RPM.

If it goes higher than the engine is rated for then the pitch is probably to small.

It may be that the boat can go even faster.

The best thing though would be the savings in fuel because you could cruise at the same speed at a reduced rpm.

Dick Baner · Post by **Dick Baner** » Mon Aug 22, 2011 5:27 pm

Thanks Gary, I will have to wait for awhile as the boat is on the hard at the moment having the automotive distributors with vacuum advance removed and replaced with marine electronic distributors. Also since the engines were replaced last winter they were not alligned and we now find several of the mounts are rusted too badly to make any adjustments so in the process of finding used parts for that. I may yet get to use the boat this season. db

Al Benton · Post by **Al Benton** » Mon Aug 22, 2011 8:45 pm

Dick, I hope you get to use her this season, probably not looking good for the Quincy Classic Cruise, I'm guessing.

Al

Dick Baner · Post by **Dick Baner** » Tue Aug 23, 2011 7:54 am

Al, Yep I have given up on that again and will be at Quincy with the Carver. They are expecting 80 boats. John and Carolynn Thompson will be there with Don and Kathy Parker and we will be launching at Hannibal to run to Quincy with the cruisers. See you there.

jfrprops · Post by **jfrprops** » Tue Aug 23, 2011 10:21 am

Come on Dick, have you forgotten your sistership buddy in Virginia? That boat has 1.5 trans....original props are marked 1015 and 1014
original Chris Craft stamped B4473 and 74.

I am currently running, with the 350's like you have and the same 1.5 reduction, Michigal Wheel corp #'s 15R16 and 15L16, with trim tabs I have found that a good combination.....

Welcome comments from all on that setup.

HURRICANE HEADING FOR US.....hope it does not do to us what the flooding has done to you and Al.

John in Va.

Dick Baner · Post by **Dick Baner** » Tue Aug 23, 2011 10:42 am

Hello John, I may have had those numbers mixed up and the props are 14 dia by 16 pitch instead of the other way around. That would probably be better as my understanding is that pitch has more effect on RPM than diameter, at least that is the case with an I/O.

Al Benton · Post by **Al Benton** » Tue Aug 23, 2011 1:54 pm

Dick, I'm glad that you will be there with the Carver. Look forward to seeing you on the river at Hannibal. It's great that the Thompsons and Parkers from Heartland Classics Chapter will be joining us. Did you make it down to Table Rock Lake in June for the Cruisin' Classics weekend?

Al

Dick Baner · Post by **Dick Baner** » Tue Aug 23, 2011 3:34 pm

Nope, had a granddaughter graduation that weekend. Next year is the big one down there as they are hosting the ACBS annual national show at the Big Bear Lodge on Table Rock Lake. Parkers are the chairpersons for it I think.

Al Benton · Post by **Al Benton** » Tue Aug 23, 2011 7:33 pm

This event was called Cruisin' Woodies for years until a couple of their members started bringing their nicely restored XK18's. They changed it to Cruisin' Classics so they didn't feel out of place. It will be done in conjuction with the Annual Meeting and Boat Show as a pre-event next year.

propellor spec information

propellor spec information

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