prop ideas?

[Greg Faulkner]

Hi folks,

I'm new to this site....but not new to my Formula. It's a 1979 F233 LS (Intercepter) with two Merc 260's that I bought in the mid 80's. I live in the San Francisco bay area and used to blast around on it years ago on the bay chasing girls etc. I had a lot of fun in those days, and some of it, quite honestly, I don't even remember.

Then it went to Clear Lake in Nor Cal for a few years. In 1992 I blew a head gasket on one motor....enter the domino theory. I decided then to redo everything and make it the way I wanted it be. Well numerous other things got in the way, work, marriage, kids, deaths and money, such that my project was never finished.....BUT NOW I have opened the project up again to finish getting it going for among other things, viewing the America's Cup (sail boat race) later in July and August on the San Francisco Bay.

 

To date, here's whats been done:

 

Stripped the insides out, everything, reglassed the cockpit deck, redid one engine mounting pad, new front seats and posts, all new ulpholstery, new carpet, new headliner, all new rebuilt motors (pretty much stock), new Stainless Marine exhaust ($$$), new gimbals, new upper and lower outdrives from Sterndrive Engineering including upgrade to a counter-rotating port side, all new exterior paint (I never liked the original faded-looking watermelon red), added white texture paint to the topside decking area, new side graphics are being installed this weekend, new fuel sender, new remote mounted oil filters, new trailer, all refreshed wood work (yet to be installed), new bulkhead walls between cockpit and cabin, literally everything that could be taken apart was, and redone or replaced or upgraded. Eventually I will be replacing all of the gauges but not immediately.

Yes...it's been an expensive long and winding road. probably should of / could of just bought a new boat....but then again, it wouldn't be a 79 233LS!

Now for a question.

When I first bought the boat it had a set of Clever props on it, both right hand drives, 15 x 23, supposedly repitched to 25. They even had an additional stamp on them that said 25c. I never was quite sure if just the prop ends might have been recupped or whatever to 25's. Some have told me that to truely repitch a stainless 23 to 25 is impossible. Never-the-less this is what they say and were. In the early 90's I lost one prop when a lower unit output shaft broke off. (How many of you know that in at least the early Alpha's the output shaft was apparently a fused together combination of tool steel on the inside and stainless on the outside?) That joint is where mine broke.

Anyway, now I want better props....clevers are generally considered old technology and I have to get a new left hand drive prop anyway so I guess I will pop for two new props.

But which ones?

It's been too long since I was out on it to remember what the RPMs the engines hit....I suspect they easily hit 4800. I would bet the thing ran a good 60mph, probably a little more on good days. With two right hand drives the hull tended to torque a bit so the trim tabs were in use pretty regularly probably adding a little drag. I am pretty excited what the difference will be with balanced conter-rotating units.

So, to those who have similar boats, maybe I can tap into your successful experience?

I am assuming stainless is again the way to go.

What's the recommended props?

Brands?

23 pitch or 25's

I will try to eventually get a few shots of it up on the site at some point.

 

Any help is much appreciated.

 

Greg

 

 

 

 

 

 

 

 

[Dave Holm]

Hi Greg,

              there is a site called http://www.offshoreonly.com/forums/forum.php  that has a prop expert on it and he helped me out lots.

He frequents the tecnical area under Prop Talk and his handle is :bbladesprops

He can also help you out with prices.

 

Cheers Dave

 

[Greg Faulkner]

Hey Dave,

Thanks for the lead....I have casually looked at that site a bit over the years but will check it out more in depth....

Happy 4th.

 

Greg

[David]

That is Brent from BBlades.  He understands what the 233 likes, mainly a lot of bow lift.  He did the props on my 233 and they work great as well as providing much better fuel economy.  Remember, props are a compromise so you need to decide what is most important, speed, economy, durability, acceleration etc.  Hydromotive is another good company to work with.  Good luck!

[Greg Faulkner]

Thanks Dave....I will check Brent out.....I have just been swamped with som many other smaller things that need completeing. Sounds like you might have a twin engine 233....if so, what props did you and Brent finally settle in on?

 

Greg

[Kevin]

I have been wondering what props to try as well. I just picked my 233 up from Missouri last Fall. It is an 81 F233 LS Interceptor with twin 260,s. I believe they are stock except for HEI ignition and eddelbrock aluminum intakes. I have been told the cleaver props on the boat are not a good match for it. Im not sure exactly what the specs are on them. I am assuming they are 23 pitch. Here is the number on the props (48 88150A 4 23P) and (MAZCO 782). I have never been in a 233 before this boat but it seems to have a tougher time planing off than it should. Unless the trim tabs and outdrives are all the way down the bow will rise really high and then cavitate. I am hoping different props will help alot with this. Im not sure of my wide open rpm yet because my tachs dont seem to be accurate, but i have hade the boat to 60mph two times so far with ease. Im still working all the bugs out so i dont want to push it too much yet. I can post rpm's and speeds within a week or two hopefully. I plan to stay with stainless as well. What do you guys think about 4 blade props on these boats?

[David]

Greg and Kevin,

Clevers are old tech.  My props are Mercury Thunderbolts, same as Mirage.  3 blade round ear.  Brent at B Blades tweaked and thinned them.  He doesn't provide specs and keeps it proprietary.  Originally the props were 23".  My 233 runs in the low 60's.  They are heavy and hard to get to go fast.  I run twin 260's that were rebuilt .060 over with good cam, heads, intake and exhaust.  Kept original quadrajets.  Boat is bulletproof, would run 60 all day.  I did my props 4-5 years ago so there may be some new tech out.  Brent can help you or Tom at Hydromotive.

[Jon Craig]

Interesting discussion as I have been going thru prop testing on my '73 233F - only difference being I have twin 225ho etecs on a bracket.  I ran  4 blade Bravo 24p to start & it was like I had my trim tabs buried.  Very smooth ride, but I couldn't get my nose up.  I then tried 4 blade Rev4 23p, and gained 5 mph at the same 5300rpm (58 mph).  I need to be at 5600rpm though, so I am about to try a pair of Mirage Plus 21p this weekend (hopefully).  My gear cases are 1.85 ratio.

For me, I am not after top speed - more about handling & mid-range efficiency as I do a lot of fishing/family stuff.  I liked what everyone said the 4 blade props do, but I just don't think the 233 hull likes them all that much.  I know other guys w/ twin 250 ob's running Mirage plus 23p were seeing better #'s than me w/ the 4 blades. 

If all I wanted was top speed, I would be looking at a set of Mirage+ 23p & maybe have Brent tweak them.  I might hit the limiters w/ the 21p when light, but I also run w/ decent loads and in some rough conditions where a slightly smaller prop is good. 

I did see a decent amount of chine walk as I hit 58mph.  You guys seeing this at all?

[David]

I can't address outboard vs IO but I can say that chine walk is not an issue at all with my 233.  It will run low 60's for as long as I want without undue stress on the engines.  I would certainly reach out to Brent and take advantage of his knowledge.  Very happy with my results.  Efficiency is greatly improved also.