Barefoot Props |
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tullfooter
Grand Poobah Joined: March-02-2007 Location: White Lake, MI Status: Offline Points: 2225 |
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You know it. Tim, I've got the dial style timing light. I should be all set with this and will report my findings after the weekend. |
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Play hard, life's not a trial run.
'85 BFN '90 BFN White Lake, Michigan |
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tbeard
Senior Member Joined: April-26-2012 Location: Fort Worth TX Status: Offline Points: 379 |
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When I bought the boat I had no idea where the thing ran or how accurate the speedos were set. The previous owner was a wake boarder that hardley used the boat and knew little about performance. He had a boat performance shop keep the boat tuned and running for him.
We took a GPS and set the speedos (so I know they are correct) Tach locked at 4200 wide open. Guess I could take a external tach and check it....But the motor does not sound like is is turning huge Rs. |
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Thanks.......Tom
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tullfooter
Grand Poobah Joined: March-02-2007 Location: White Lake, MI Status: Offline Points: 2225 |
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My timing was almost dead on at 10 BTDC. I advanced it a couple degrees. It sounded better at idle. I'm not sure what the advance timing is (at 2500 rpm), but I will check tonight. We could only get 40.5 mph (GPS) with a 185lb footer in tow and 4 guys in the boat. Not bad, but I'm hoping to get a couple more mph tonight.
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Play hard, life's not a trial run.
'85 BFN '90 BFN White Lake, Michigan |
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hotboat
Gold Member Joined: March-28-2009 Location: Conn Lake Pa Status: Offline Points: 814 |
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At what rpm Steve? The 40,5 I'm talkin
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Brian
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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Im more curious what the final timing is than the initial.
Rev up to 3k rpm in neutral and see what you have. |
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tullfooter
Grand Poobah Joined: March-02-2007 Location: White Lake, MI Status: Offline Points: 2225 |
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Final timing at 3000 r's was 35. The strange thing is that my static timing (at 700 r's), according to my timing light as 18 BTDC. I took it on the water by myself and was running 4500 rpms at WOT, and just hitting 45mph. It is what it is for the time being. There is not much I can change between now and Saturday's Buckethead Barefoot race. |
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Play hard, life's not a trial run.
'85 BFN '90 BFN White Lake, Michigan |
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hotboat
Gold Member Joined: March-28-2009 Location: Conn Lake Pa Status: Offline Points: 814 |
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All those numbers look good Steve and you picked up about 200 rpm it appears, that's as good as you'll do on that I would say, may drop it down 3 degrees. Do you actually run 38 miles wide open? Sweet
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Brian
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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With the extra cup thats been added to that 542, it appears to be running revs more consistent with a 540. Your top end numbers are similar to the early 2001's with the 351w, so still about 500rpm and 5mph short of where you should be... are you sure you have a big block under the doghouse? Are your secondaries coming in all the way?
Timing seems fine with 35 deg total advance. I assume you took it a bit past that to make sure it would not advance any further? I thought you said base timing was 10deg, so Im not sure what changed between then and when you got 18deg... was that after a hard run (weights hung up?)? |
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hotboat
Gold Member Joined: March-28-2009 Location: Conn Lake Pa Status: Offline Points: 814 |
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Tim do you feel the prop on my Martinique could help him at all? I know my 540 would fall on its face at a certain point. It dropped mine 400 rpm and gained 5 mph roughly.
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Brian
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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There is a world of difference between running in the mid-upper 50's (and the RPM's associated with those speeds) and the mid 40's. Where your Martinique is pushing the limits of its hull and driveline components, Steve's BFN is underperforming by a good bit...
A healthy 454 in an early (pre-87) Barefoot Nautique should pull a stock sized prop (13x15 Fed, 14x14 Fed/OJ, 13x14 Acme) around 4400rpm, and hit speeds of 49-50mph (unloaded) at a minimum. An Acme 430 (13x13) like youve got would run in the 4700rpm range, I would guess... and speed would likely be about the same. A 540 would run even more revs (~5000), and speed might be a tick slower, as the WOT rpm's would then be a good bit higher than the engine's hp peak (4400). Holeshot would be much improved though. What we dont know is why Steve's particular combination isnt performing up to snuff. It should be capable of pulling that cupped 542 a lot more than 4500rpm. If its simply a tuning issue, then a slightly larger prop (generally speaking) should be a better all around performer on that hull/powertrain combination. If the engine is simply tired, then continuing to run the smaller prop at the current RPM's he's seeing is probably less stressful on the components and will yield the best performance one could expect. |
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tbeard
Senior Member Joined: April-26-2012 Location: Fort Worth TX Status: Offline Points: 379 |
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What is the Max RPMs a 1988 PCM 330 HP 454 can be pushed to. I do know from my muscle cars there is a point where valve float is at risk due to high RPM. The reason I am asking is I am considering a winter tear down and basic rebuild with just a hone/rings, bearings, timing chain and gaskets, oil pump. Not sure what I want to do with the heads yet but I do not want to make any changes that will reduce the gas milage. (increase fuel consumption) My reasoning is I have no idea the actual hours on the boat/drive train. Clock says 500 now but we all know those can be un plugged. If I do this much work I want to make sure I prop it right with no risk of valve float.
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Thanks.......Tom
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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This is where the reference section is your friend,depending which 454 you have there 2 different answers. If you are not over reving it now, just by changing the parts you mentioned won't change anything unless it's really worn out and you have reproped to that. Now if you were to change the manifold, cam and springs that will.
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tbeard
Senior Member Joined: April-26-2012 Location: Fort Worth TX Status: Offline Points: 379 |
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Thanks Gary.....Did not know all the engine info was there.....Or mabey I just forgot. Excellent I am 99 % confident my engine is not the high compression/390HP 454 . But I will check the data plate if I can still read it.
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Thanks.......Tom
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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Your welcome Tom. Even though I don't have a PCM I have found that they have alot of knowledge in them and have used them up until I found the manual for mine.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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The max "safe" rpm of a stock PCM engine is really not that important. Just know that its quite a bit higher than you'd want to spin the engine for optimal performance. My guess is 5200 is plenty safe, most likely its a good bit higher. You'll start getting lousier and lousier performance and economy as you prop the boat to turn north of 4600, as you would be continuing to move further away from the point where you make peak hp (4400).
I think we've only seen one HO 454 in a CC posted recently, though there are supposedly several running around. They were wild LH motors that were dealer installed though, so certainly not run of the mill like the 330hp versions. I would strongly consider a warmer top end on the motor if youre going to all the trouble to rebuild the bottom. The stock peanut port heads are pretty lousy- a set of large ovals (like the 781 or 049 castings) would be a huge improvement. Rectangles would be overkill and come with a penalty at the low to midrange... but run great up top if youre so inclined. A slightly warmer cam and a decent intake manifold would really wake the boat up. Greg has such a combo in his '88 and is running around 53mph... ask him how he likes it. I see no reason why a modest bump in hp would correlate to a major increase in fuel consumption... after all, engines are air pumps and better breathing parts simply make them more efficient. FYI, I tried the 430 on our '79 this past weekend, and as expected, it turns 300-400 more RPM than the 1598. Its definitely an improvement out of the hole. Thats the prop I would put on your boat if you can verify 2 things: 1) You have a stock sized (14x14) prop on it now 2) The 4200 RPM you are turning at WOT is accurate Bring the GPS with you next time. Airguides are pretty decent throughout the band, but can be off a little at WOT... so if you set them at skiing speeds, they may not be 100% believable in the mid-upper 40's. 48-49mph is at least 1-2mph higher than I would have expected, especially considering your rpm's are on the low side by about 200rpm. |
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phatsat67
Grand Poobah Joined: March-13-2006 Location: Indiana Status: Offline Points: 6150 |
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Just fyi I believe the guys in the red boat we re gelled ran the 1598 at the bucket head that weekend and loved it. I don't know actual numbers from the race. I think Mark is spining the 430 on his 91 I'll have to verify.
Not barefoot talk but the gps is coming out and the 540 is going on this weekend Tim. .....I smell gt40 heads, and a different intake this winter. |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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A 430 on a '91 would be incorrect, I would think... doesnt the v-drive have a reduction?
For heavy loads on a stock later direct drive (87-90), I think the 430 should get strong consideration... though the 1598 is surely worlds better than the stock 14x14, and turns similar revs. The pre-87 hulls seem to run a bit faster and can spin the 1598 closer to the 4400-4600 range if theyre in a good state of tune. I think youre going to like that 540... it really turns a stock 351w 2001 into a very competent performer. The only thing you'll miss is 1-2mph for one-foot stuff (you'll see about 41mph with a footer). Heads/cam/intake is the solution for that, though. |
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hotboat
Gold Member Joined: March-28-2009 Location: Conn Lake Pa Status: Offline Points: 814 |
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91 yes reduction and we carry a larger shaft
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Brian
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BuffaloBFN
Grand Poobah Joined: June-24-2007 Location: Gainesville,GA Status: Offline Points: 6094 |
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I luv it! The 53 is a bit lower now though after sorting the lifters. I'm turning about 4900 now and need to do some tuning, but the combo is great. I put the 781(049 Tim ) heads on with domed pistons bringing the compression up to just a hair over 10 to 1. I also added a slightly warmer cam than came stock along with the HEI DUI. In short, it has a mean kick and gets to WOT in a hurry. |
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phatsat67
Grand Poobah Joined: March-13-2006 Location: Indiana Status: Offline Points: 6150 |
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Yeah Tim. I retract my 430 statement about the v dive boat. Ill have to ask mark what number it is. The prop has one of those bullet nuts over it so I cant see the digits. The 91 was in the bucket head this year to though she looks pretty rough.
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tbeard
Senior Member Joined: April-26-2012 Location: Fort Worth TX Status: Offline Points: 379 |
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Man great feedback. I love the idea of redoing the top end! My Muscle car experience with Big Block High Horse power motors is one of the reasons I bought this boat. Plus the quality of the boat, wake and how it drives/rides through chop. The reason I wanted to do a re-fresh only is once I start down the road or performance improvements I would not keep the cost down. Not sure I am ready to go that deep into the motor this year. I still need to do Gel coat work, decals and interior. I did find some 781 heads on Craigs List for $ 200.00. I cosider these core so another $ 500.00 would make them ready to bolt on. May do this to let the thing flow and breath.
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Thanks.......Tom
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tbeard
Senior Member Joined: April-26-2012 Location: Fort Worth TX Status: Offline Points: 379 |
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Tim...The prop on the boat is the factory 14 RH 14 Federal. Ryan and I are skiing tomorrow night. I have my Meter/Tach in my ski bag:) Will get the actual RPMs.
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Thanks.......Tom
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SN206
Grand Poobah Joined: February-25-2009 Location: Fort Worth, TX Status: Offline Points: 2339 |
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A local shop suggested trying the 540 on Tom's BFN. Thoughts?
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...those who have fallen and those who will.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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If you've got a 540 to try, go for it. If you would have to buy it, I'd pass... It will turn way too many revs (5000+). Great holeshot though.
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