Barefoot Props

A local shop suggested trying the 540 on Tom's BFN. Thoughts?

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.

TRBenj wrote:    Greg has such a combo in his '88 and is running around 53mph... ask him how he likes it.

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.

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.

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.

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.

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.

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.

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

Im more curious what the final timing is than the initial.

Rev up to 3k rpm in neutral and see what you have.

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.

hotboat wrote: Puttin the pressure on now aren't ya?

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.

Tim bringing your bfn?

Puttin the pressure on now aren't ya?

Great thread....My 88 BFN has some vibration (not terrible but annoying) This winter I am going to restore the boat. The previous owner hit something and had the prop cold worked on the boat and the repair looks bad. I have been planning to take the prop to a shop and have it repaired and re balanced. But I wanted some feedback on the performance of the boat...Wide open 4200 RPM at 48 - 49 MPH. Hole shot is strong and the exceleration is excellent. May be a POS prop but the boat runns like a stripped ape. Any feedback would be great...