rws

The 280 tabs are tapered to clear the outdrive when you turn. 18" is mighty wide tab.I have 19" long tabs on my 24 Python they are very sensitive to adjustment and took a few hours to get used to.a Bravo1 or Revolution prop is what i run on my boat.One problem that you may run into is exhaust to hatch clearance when you raise the X dimension.17 1/2" should work fine but you will not like the cleaver (slippage) getting on plane.With the small block don't be afraid to let the engine spin some rpms vs lugging it tring to pull a large pitch prop.

Stormrider

go w/ the short kplanes.
had them on my 24pantera and did not ever make the boat trip up.

79 excalibur 24

I think i will go with the 12'' x 16'' bennett tabs with 2 cylinders for now. I also think the 18'' wide tabs i have are a little to wide. and i cant afford the 280's right now I still need to find a gimble and bravo one before spring. I will try the 23 mirage to start with. I know the cams powerband has a peak hp at 6300 rpm. Should i find a prop that i can turn that high or should i keep the rpms around 5500 or so?

79 excalibur 24

another question i have is with the short imco lowers. I know that would save me a lot of work from raising the hole engine and drive and like rws said maybe even the exhaust. but i have now idea how much they cost and if its just a housing and i have to swap out parts from a bravo or is it a hole lower? Im new at the go fast game but so far i love every second of it. Boats are like drag cars you build them up till something breaks than upgrade to hold up to the power and before you know it you bump up the power and something else breaks. But Damn its fun...

Hang Time 27

There are few prop experts, but you can easily find a zillion opinions. The best thing you can do is trial and error, since no two boats are set up exactly the same, and driver preferences differ. You won't know for sure how it will act till you try it - use e-bay - plan on buying props for $150 (the bargains) to $250 for merc stuff - bravo ones and mirage plus's - aftermarket props are harder to come by on there. Try 'em, and if you don't like them, put them back on there for $10 more than you paid (inlcuding shipping) I even picked up a pair of 29 mirage plus's for $400 that ended up being labbed!!!! Bargain for me......

The 16" long bennet tabs use two pistons per side for more strength, and then use one motor for each side to get the speed back up - one motor running 4 pistons will actuate pretty slow............

Budget tabs :
If you both narrow and lengthen your tabs, and pick up two more pistons and one more motor, your there (again available on e-bay). Keep an eye out for used 16" bennets on there too. Just make sure you mount them so they can they can pull up and out of the way when not used - they must lift higher, the longer they are!!!

Hang Time 27

But do drag cars have an acronym like "B.O.A.T = Break Out Another Thou!" It's so damn true it hurts.............

Yes check out the Imco shorty - it's the whole lower - shorter shaft in there, etc. Not cheap, but might come close if you were to pay someone to do your fiberglass work and engin alignment/install, etc. If for some reason the shorty is too short - they might have spacers in diff lengths to bring you back down. (available for standard bravo's, not positive on imco shorties's)............Usually, as your drive height goes up (to reduce drag) you end up with more slip and the need to go to 4, 5, 6 blade props. Kinda like needin slicks to go with your 4.11's. They didn't start making the higher blade number props until guys/manufacturers started raising thier drives..............

Hang Time 27

It'll partially depend on your desire for cruise speed, and what rpm you want to do that...at. On mine, the feel good/run good minumum cruise for the hull was 50mph (3,500 rpm), and 60 was worlds better (4,000rpm) with 25 mirage - these size/style boats just feel better the faster they go at cruise. My guess is that a 23 would put you @ 4,500 rpm for 60mph?. 4-blade would drop down a few hundred. Just make sure you run a oil temp gauge to see what your constant high rpm heat issues are - if any...........

79 excalibur 24

Thats funny about the ebay thing. I have been bidding on bennett tabs and sst props this past week. Thats where i got my 23 mirage and i just won a full used set of bennett tabs. Not the 16 inch ones but i think i will do like you said. cut down my tabs and install the other 2 cylinders and pump . Great minds think alike.. Another Question is where to locate the tabs? Thay are i would say one inch above the bottom of the hull. How far down the v should thay be? Should i cut the outside of or the inside??? And 6 inches off each should work to get to the 12 inch wide and weld on sst plate 16 inches long.

79 excalibur 24

I dont cruise much under 45mph or so. The boat starts to porpoise any slower. Even with the tabs in. It dose feel good at about 50 or so. I Should start to look for 4 and 5 blade props i know. I have 3 blades all over the garage because you can pick them up much cheaper. I had a nice 23p 5 blade that i let a good friend try out ( Yes thats you Fuller) But its At the bottom of the mississippi right now. LOL

Hang Time 27

You usually see tabs mounted as close to the center of the boat as you can (so they still contact the water well as the hull gets higher out of the water). Long performance k-planes are usually tappered to reduce drag, and are only angled heavily on the drive side on narrow hulls or twin drives to clear the drives as they turn. Inch up is good, I think mine where closer to 1/2, but I was refering to the rear edge of the tab when it is all the way up - how far up will it be from the bottom plane of the hull

Warning : A friend just mounted my old 16" bennets with one of the twin pistons in the same place as his old piston, and this left his up position almost parallel with the bottom of the boat!! he was just trying to save the trouble of sealing and drilling more holes. -- you want to be able to carry the bow if you want without the tabs touching. The rear of my factory mounted 20" long k-planes are 4" above a 2x4 placed against the bottom of the hull, and are 3.25" high at the 16" mark.

PS we should have started a seperate thread on this......huh