Barefoot Props

How many rpm's are you turning with the 542? Only from what I've read...seems the BBC would over spin that one? Shows what I don't know about the different sizes.

I got a 1598 on advice from here; luv it.

Agreed an acme 542 would be way too small a pitch prop for a healthy barefooter with a 454.

An acme 540 will also usually spin too fast and use more fuel than necessary for all around day to day usage. But, if you are looking for maximum holeshot and are regularly pulling multiple deeps or bigger guys then it can be a good choice.

An acme 430 is a good all around choice.

OJ makes several fine choices as well depending on your performance goals.. but I dont have direct experience driving barefoots with them.     

BuffaloBFN wrote: footer89 wrote: Currently I have an Acme 542 that was tweaked by Acme to give a few extra rpms. Something is amiss.

I agree but, maybe he's turning that big block at over 6500!

I think it's time for a rebuild (1750 hours). My 542 ( P.O. says the prop was "custom" made for the boat, something about a .115 cup) is only spinning around 4300.

Steve I know where there's a bfn for sale that's not tired 700 hrs,, my garage

You bet, only had it out once this year so far about a month ago. Craziest summer at work in years as well as put my last dog down but got a new e mastiff 2 nights ago

tullfooter wrote: I think it's time for a rebuild (1750 hours). My 542 ( P.O. says the prop was "custom" made for the boat, something about a .115 cup) is only spinning around 4300.

I would imagine that's only 41mph or so (unloaded)? And only pulling a footer ~39? Is that right? Get a gps to confirm.

Either your tach can't be trusted, or you've got some major issues. It should be downright scary out of the hole with that prop on a 454.

mdvalant wrote: We run a 1598 on the 07 330 excal for show team use. That prop is a hoss. Sorry, no idea about BFN's but didn't know anyone else used a 1598 for anything. Neat to know what you guys like that on.

I've heard of some 1.23-1.26 boats running 13x14's for ski team duty. Gotta be a nice holeshot/pulling prop on boats that came with ~13x15.5 wheels.

The original application for that prop was the big block 1:1 boats, which ran 14x14's from the factory.

BTW

I have two band new stock props that came with the boat. Do you think the stock prop would add top end?

Steve, you're missing 7-8mph, that's kind of a big deal. Have you verified the speedos with a gps? The airguides are only as accurate as you set them to be.

If the speed is correct, Then how handy are you? I'd be going through the ignition system first- when's the last time it was tuned up, timing set, etc? If recent, then compression test it.

I would not be swapping props. Unless you're pinging on the 87, you won't see better performance with 93. Higher octane doesnt give you more power. More final timing might (ideally you want about 35 deg) and sometimes you need higher octane to keep from pinging with extra timing... But the gas alone doesnt add hp.

Steve that 32-36 degrees will be total timing advance at max or WOT rpms. It is the static advance at idle plus the advance provided by the mechanical system in distributor.

You can keep increasing your static advance until you get your required total advance at WOT. Keep your ear tuned for pinging (sometimes called detonation with good reason ). This is where the higher octane fuel helps.

Set the initial timing at idle; probably 650 rpm's. The advance mechanism in your distributer controls the advance from idle on up the rpm range. If you have the original set-up, you have weights and springs that make up your advance mechanism under the mounting plate for the points and condensor. Also, you don't really set final advance. You set the initial and then check the advance. You either need a nice light or timing tape on your balancer to see where she falls.

These parts can get rusty over time and cost performance. I don't know your maintence routines, but since you're asking about it...   

4200 and 48.5 mph. Nice!
This site is great. 10 minutes after I posted, Brian (hotboat) gave me a call to help with my questions. It's almost as if you have a group of buddies along side when you need help with your boat.   
And Brians thinking of heading to the Buckethead. Hope you do.

48-49 would be stronger than typical performance for a stock 88. Are those numbers gps verified? 47 would be typical. 4200 is on the low side for the stock 14x14 prop and would not equate to that speed... So something doesn't add up.

Steve, final advance is checked in neutral. A timing light with a built in advance dial helps. Hopefully the timing is all in by 3k rpm but check to see where it stops advancing.

Steve, I will get you my prop specs but it will be next weekend. I will not be down at the river this weekend and I have no idea what prop is on my boat. (I know that sounds bad but I bought the boat in May and we have skied the hell out of it for 3 months without much reguard to the drivetrain) It runs so good my thoughts were do not try to fix something that is not broke. All I did was change the oil and plugs and ski it:)
As far as your 454 I am a old school BB fan and have found they are very reliable without much maintenance. I would be surprised if you have an engine issue all of a sudden. My suggestion is eliminate other issues first...get an accurate read on RPM, speedo, and then I would focus on external things like prop, ignition and carb, vac leak...things like that.