Prop for the 86.?
Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: Common Questions
Forum Discription: Visit here first for common questions regarding your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=8973
Printed Date: April-27-2024 at 1:31am
Topic: Prop for the 86.?
Posted By: phatsat67
Subject: Prop for the 86.?
Date Posted: November-12-2007 at 10:06pm
| Would a Federal Super Cup 13x12xR1. be the right prop for my 86 stock 351 nautique? It has an unknown(because I havent pulled it off) 4 blade prop and it will only turn 4000 rpm's at 44mph and doesnt have the stuff out of the hole Id like it too. It runs about 3000 at 36 and With a skier with deecent pull behind it you have to give it a fair ammount of throttle to keep it at speed when in the cut. Thanks for the info. |
Replies:
Posted By: Barracuda
Date Posted: November-13-2007 at 7:10pm
|
The "right" prop will be the one which best suits your needs. Pretty sure that boat came from Orlando with a 13x13 Federal. That's what I run on my 86 and it treats me just fine for Skiing the course, wakeboarding and barefooting too.
Prop changes can make a big difference in your boat's overall performance. Take the prop off and check for numbers stamped into it. Post them here and someone will know what it is you've got. Good luck. ------------- Former: http://www.correctcraftfan.com/diaries/details.asp?ID=759" rel="nofollow - '86 Nautique http://www.correctcraftfan.com/diaries/details.asp?ID=507" rel="nofollow - '65 Barracuda |
Posted By: Riley
Date Posted: November-13-2007 at 7:28pm
| I bet a 13x12 Acme would work well. |
Posted By: phatsat67
Date Posted: November-13-2007 at 10:56pm
| Thanks. I thought that the stocker was a 13x12 but I thought id ask because I wasnt sure. |
Posted By: Hollywood
Date Posted: November-14-2007 at 1:40am
Has this been verified with GPS? I only ask because 36 mph @ 3k would be a dream. It's been shown on here it's going to cost you some $$$ to run mph>rpm on a 1:1 trans. Definitely not what I'd expect out of a stock 351 engine, not to mention on a 2001 hull. ------------- |
phatsat67 wrote:Posted By: jbear
Date Posted: November-14-2007 at 2:06am
|
Nate: Believe you better check that speedo man. I kinda doubt you are running 36 at 3k. That could be why you are felling the need for more pull.
john ------------- "Loud pipes save lives" AdamT sez "I'm Canadian and a beaver lover myself"... |
Posted By: 882001
Date Posted: November-14-2007 at 11:30am
|
wakeboard= acme 542 13x11.5
ski = acme 540 13x12 if your numbers are correct. im supprised you can get on a plane. your boat is probably no fun to drive and getting horrible gas millage. ------------- kemah texas http://www.correctcraftfan.com/diaries/details.asp?ID=163&yrstart=1986&yrend=1990 - 1988 skinautique "2001" |
Posted By: phatsat67
Date Posted: November-14-2007 at 6:01pm
| Yea well maybe its about 3200 at 36 I havent driven it for a month or so but I calibrated the speedos on GPS about 4 times this summer and did alot of skiing with the gps in the boat. I know for a fact that the rpm at 43-44ish is right at 4000rpms. Its seen 4100 one day when it was running freaky good. I know it doesnt have it out of hole like it should. I dono maybe my tach is off but the sound of the engine sounds right. Its easier to tell at idle if the tach is right and it sounds like it should when it idles at 800 out of gear. But Id like to get more stank out of the hole because you cant hear the secondaries open up untill it gets to around 2800 or so which makes for slow pull ups. It wasnt a serious problem and I didnt have the money for a new prop so I just used it like that all summer. It actually gets better mileage than my dads MC might be because of the low rpm crusing once its up on plane. I will pull the nut off tonight and check the pitch. Ill keep this prop as a spair and maybe throw it on if I go down to lake cumberland for the long runs at high speed to keep the r's down. |
Posted By: 64X55
Date Posted: November-14-2007 at 6:17pm
|
Hey phatsat67!
Is that the boat with my old windshield on it? If you lean that glass back a little, you should pick up some top end! 
Just kidding! Here's a link to a neat little prop calculator: http://www.rbbi.com/folders/prop/propcalc.htm You can work backwards to try to guess the pitch of your prop and confirm it by your observed speeds. I played with it some with the known gear ratio (1:1) and the other known factors (observed speeds and observed rpm's). It didn't seem like 3600 rpm's and 30 mph fit right. With an assumed 13" pitch prop it calculated only 2.5% slip (which seems real low), while your 44 mph at 4400 rpm's (and, again, an assumed 13" pitch prop) yielded 10.6% slip, which sounds more realistic. I've seen info. that suggests slip for "planing runabouts" to be from 15% to 25% (a pretty big range). As I've played with these calculators, or just done the math, it seems like most are in a slippage range of 10% (on the low side)and the high teens (on the high side). Another factor is that I think a "cupped" prop has the effect of adding maybe 2" of pitch (or something like that). Then you gotta think the slippage is probably different at different speeds too! That makes it more fun! 64X55  ------------- Inboards Rule! |
Posted By: phatsat67
Date Posted: November-14-2007 at 6:21pm
|
Heyy thanks X. Yea that windshield is lookin great. Just cleaned it the other night haha. Hows your boats treating you. Ill check out that calculator.
edit: so I took all of the stock "Specs" reviews say 4400 at 44mph with the 12 pitch which gave me a .12 slip so i took the .12 slip an put in what my boat does. It says its about a 13.00 which sounds like it would be way to much prop for the boat especially in a 4 blade configuration. Ill try to verify the pitch tonight when I get home. |
Posted By: phatsat67
Date Posted: November-14-2007 at 11:45pm
| Alright So I went out and pulled the castle nut off tonight and found out thats its a cupped 13x13 oj legend 4 blade prop. Too much for the boat ya think? |
Posted By: phatsat67
Date Posted: November-18-2007 at 3:08pm
| So we think that would be a much better prop for my boat? I need to know today the auction is over soon. The super cup will be alright also? |
Posted By: 64X55
Date Posted: November-18-2007 at 8:40pm
|
Whoa! phatsat67 - didn't know you were counting on a reply to bid on something (I must have skimmed too much above there). So you've got a 13x13 4 blade and the specs say you should have a 12 pitch (assume that's for 3 blade)? You didn't metion the diameter; is stock 13x12? And what is the auction for?
Additional cup will lower your rpms; but it should help all around I would think unless it's so much cup that it really takes your rpms way down. Sounds like you're wanting to get them up, right? Sorry didn't check in for a while! Maybe the auction is over by now! My boat is just out there patiently waiting for me to get back to work on it! Probably told you before, I got my "original (correct) windshield" back in the summer, but I haven't done much lately. Winterized the engine because I had it started a couple times since spring. I could work on it some through the winter if I get myself motivated (and if I had some "spare" money for some of that really economical to buy 3/8" mahogany marine plywood). I think Pete (8122pbrainard) found some for as low as "under" $200 per sheet! What a deal, huh?!?!?!! Let's see; how many sheets do I need... Hope you get the right prop! It's interesting; the little Dunphy X-55's came with a Michigan 12x15 cupped prop which is a pretty high pitch! ------------- Inboards Rule! |
Posted By: TRBenj
Date Posted: November-18-2007 at 9:39pm
The 13x13 OJ is clearly too much prop for your boat. The 13x12 should get the RPM's into the range youre looking for, especially since youre wakeboarding. Not sure what your budget is, but a new Acme would perform worlds better than either of them. Theyre worth the $300. ------------- |
Posted By: phatsat67
Date Posted: November-19-2007 at 1:42am
| Yea We dont wakeboard behind my boat How dare you imply that haha. It gets all slalom/trick/kneeboard and jump if we had one. The practice lake we slalom on is really small and rite now with a skier you have to hold her wide open till the gate to get it to 36mph. Oh yea Im a college student soo im not looking to buy a new acme yet although im pretty sure it would work wonders. X sounds like your about ready to get that old woodie done. Thats some serious pitch man haha I bet that runs like 2000 rpms at 36 haha. |
Posted By: TRBenj
Date Posted: November-19-2007 at 12:10pm
My bad- I assumed that you were looking at the 13x12 since it was similar in dimensions to the Acme's. The 13x12 would certainly get you up to speed quicker than the steep OJ that youre currently running. It will likely sacrifice some top end though, so if you barefoot that may be a consideration. If it were me, I wouldnt spend a dime on anything short of an Acme. Keep saving your pennies- its the single best thing you could do for your boats performance. We're talking night and day here. ------------- |
Posted By: Hollywood
Date Posted: November-19-2007 at 1:11pm
Obviously you're not a golfer. Ask ACME to send you a prop to test, next thing you know you'll be racking your brain on how you're going to pay for it. There is no way you'll send it back. ------------- |
Posted By: phatsat67
Date Posted: November-19-2007 at 1:59pm
| Its cool TRB. Do you think I could get pitch taken out of the OJ on my boat or have the cupping removed? I ended up loosing the auction because Ebay screwed up I put in a number and it said it was less than the bid but it was not. Anyways the search goes on. They really let you test their props hollywood? What do you mean im not a golfer haha? Thanks for all the help and info. |
Posted By: TRBenj
Date Posted: November-19-2007 at 2:49pm
Yes, its possible. It will probably cost you $80-100 at a minumum, and very possibly more than that. Like I said, I wouldnt spend a dime on anything other than an Acme 540. Id put the $100+ youre considering spending on another prop or a rebuild towards it, and keep saving until spring. ------------- |
Posted By: phatsat67
Date Posted: November-19-2007 at 3:01pm
| Thats the only problem the saving till spring is going to school so Anything saved will be for school but I will see what I can do. |
Posted By: Barracuda
Date Posted: November-19-2007 at 3:32pm
It's a quote from the movie the Big Lebowski.... ------------- Former: http://www.correctcraftfan.com/diaries/details.asp?ID=759" rel="nofollow - '86 Nautique http://www.correctcraftfan.com/diaries/details.asp?ID=507" rel="nofollow - '65 Barracuda |
Posted By: 64X55
Date Posted: November-19-2007 at 6:17pm
Phatsat67 - I don't know about "how fast at the lower rpms." Pete would know. But from talking to him and others, the X-55 does run right around 55 mph at top end and the ole' 312 Ford Interceptor, at that speed isn't turning all that fast (like 4200 to 4500 range I think - which is pretty unusual). Think about it compared to most of these other speed vs rpm numbers you see: 55mph at 4200rpm's! ------------- Inboards Rule! |
Posted By: phatsat67
Date Posted: November-20-2007 at 3:31am
| Yea I guess thats a super light boat. Ahh Seee ive never seen that movie so I dont know haha. |
Posted By: 64X55
Date Posted: November-20-2007 at 3:11pm
|
At 17'2" it's a little over 1800 lbs I think, but the key, at least in part, is the unusual cutout corners at the stern. Once on plane and up to speed, they effectively eliminate over 7 sq. ft. (a close "guesstimate") of the bottom's rear running surface. That, it is claimed, helps considerably with the top end speed.
And the proof of their effectiveness is, I guess: how many inboard's of that approximate length, weight and horsepower (only 215) can run that fast? On the downside, I'm told the cutouts prevent the boat from being able to do the fun powerturns. Guess ya can't have everything! ------------- Inboards Rule! |
Posted By: phatsat67
Date Posted: November-20-2007 at 7:27pm
| Thats pretty cool but you dont need to power turn when your outrunning everyone else haha. |
Posted By: 64X55
Date Posted: November-21-2007 at 11:12am
I had a friend that does these barefoot ski marathons races. They use these whole different breed of boats; big (20'?) ski boats, but, while I thought they were V-drives, he tells me they're actually (many of them) stern drives that will run easily into the low to mid 50's. They foot at those speeds and for as much as 6 miles at a time! Then another of the 6 man team jumps in and they take off. The tricky part is that they take place mostly on rivers (I think) and when a guy drops, they turn hard and fast back to get him and make a switch so the wake waves wreak havoc on all the other nearby (or slightly) behind footers! It's wild! They go on for like between 20 and 40 miles sometimes! Said blood blisters on your feet can get to be a problem. Nice!  ------------- Inboards Rule! |
Posted By: phatsat67
Date Posted: November-21-2007 at 5:03pm
| One of my buddies on the ski team did a 40 mile race this year and his girlfriend was on the team footing also(bad ass chick). |
Posted By: Luchog
Date Posted: December-21-2007 at 12:17pm
|
I have a 13x12 supercup federal prop in my 80' SN.
I get 2500rpm at 22mph-boarding speed, 2500 with a skier and 2600 when weighted a bit. WOT is 39mph at 4600rpm. If you're interested in any particular rpm at a certain speed tell me I will check, I take the boat out almost every day. Overall the prop is nice, but i'd like to compare with an ACME 542 ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique Commander 351W |