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View Full Version : Prop upgrade...let me know your thoughts


markismm
02-05-2010, 11:29 PM
My brother and I own a 1984 Stars and Stripes. It has a 351w with GT-40 heads and a 1:1 tranny. We have upgraded the intake to an Edelbrock performer as well. Other than these items the boat is stock from a performance standpoint.

We use the boat primarily for slalom purposes (with a little barefooting mixed in).

Anyhow, the prop currently on the boat is the stock Ni-Bral 3 blade 13 X 13 left hand roation one inch shaft (non-splined) prop.

We are looking to updrade to a CNC prop. We plan on trying both a 3 blade and a 4 blade. I am looking for suggestions on diameter and pitch for both. I am not partial to an ACME prop or an OJ prop but plan on using one of these two brands.

Please tell me which prop you think would be best for our purpose given our current set-up and tell me what benefit you think we can expect with the prop you are suggesting. Finally, please let me know if you think there will be any down side to the prop you are suggesting. My many thanks for the suggestions in advance.

east tx skier
02-05-2010, 11:50 PM
The best advice I can give is try both of the 3 blades and send back the one that doesn't strike you as perfect. Anyone who suggests one, but who cannot say he has tried the other isn't giving you unbiased advice. Call both Bill at Acme and Eric at OJ and get them each to send you the propeller that they think will suit you best. Both are top notch as customer service goes.

I had the Acme 541 on my boat, which, other than its weight, width and hull shape, was similarly rigged engine wise to yours, 351, GT-40 heads, edelbrock performer. I ran a side by side with the OJ of the comparable size and pitch. Both were good propellers. But the OJ wasn't as good or better to the point to make me want to sell the acme. It excelled in holding speed in turns and having a bit softer pull. But the acme won out with grunt out of the hole and acceleration. Top end was pretty close. The full comparison is in the FAQ thread.

BrianM also compared props on a mid 90's 190. If I recall, he had an OJ 13x11.5 that won out with him over the 541 and the OJ 12.5x12 4 blade. Eric had recommended the 13x11.5 to me, but I had wanted to keep the props identical sizewise for my testing purposes. So that one would be a good one to ask about.

Good luck. Have fun. Compare, or you'll never know which one is really the better prop for you.

markismm
02-06-2010, 11:34 AM
Thanks for the reply. I plan on ordering both a four blade and a three blade from either OJ or ACME when I order so that I can decide which one fits my preference best. I am not conerned with additional fuel consumption or holding power through a turn so much. My real concerns are a good hole shot, holding speed well in the 30-38 mph range, and cutting down on the rooster tail if possible.

ahhudgins
02-06-2010, 01:05 PM
I went from the stock 3 blade on my 87 Powerslot, to the OJ 4 blade. I loved it! Hole shot was quicker and smoother. The speed was a lot easier to maintain with only a slight touch of the throttle. As soon as I bought my 95 Maristar, the first thing I did was swap to the OJ 4 blade. My wife rarely drives the boat any more, but even she noticed (from the passenger seat) how much quicker and quieter the boat was pulling me up deepwater barefoot. I don't think you will notice a big difference from brand to brand, but I definitely think you should try a 4 blade.

markismm
02-06-2010, 01:38 PM
I really appreciate the reply ahhudgins. I certainly plan on trying a 4 blade. What I am really trying to figure out is the specific diameter and pitch folks are suggestiing for my particular set-up. I would be curious about your diameter and pitch, but you have the powerslot which I have been told requires a different pitch and diameter for top performance than the 1:1. Once again, I appreciate the input anyhow.

DooSPX
02-06-2010, 01:51 PM
4 blades have their place, but mainly on the Powerslot boats. your best bet is to PM Eric from OJ props. tell him about your boat, and what you want from the prop. he will tell you what prop is right for you.
people can give you their opinion, but its best to ask the pro's.

FrankSchwab
02-06-2010, 02:12 PM
I gotta go with DooSPX here. The best prop for you is going to depend on whether you mostly ski, barefoot, board, tube, or foil, or whether you do a little bit of each every time out. Whether you do it with two of your skinny teenage best friends, or a capacity-plate limit of broad American behinds and a couple of fat sacks.

I think the answers you're going to get here are going to be colored by the specific use that each person has, and the specific desires that they have - I love the extra low-end hit that I get out of the 13.7x17.5 that I have on my boat now, because it doesn't bother me that the engine hits the rev limiter at 42 mph as opposed to the 45 or better I was getting with the factory 14x20. If my ego depended on max speed instead of max acceleration, I might make a different choice.

Ask the expert, or at least ask yourself what you want and what you're willing to give up. Going from the standard prop that you have now to a similar CNC'd prop will probably have nothing but positives; if you want to go away from the standard pitch on the new prop, understand the tradeoffs.

Frankly, and this is just my opinion, our boats are so overpowered for how MOST of us use them that anything near the standard recommended prop size will work fine. If you want to pull pyramids in a show, or add 3,000 pounds of ballast, or pull barefoot, then you have needs that might benefit from a prop significantly off the beaten path. For the rest of us, any of the 'middle of the road' props is simply a matter of "use more throttle", "use less throttle", "manage the throttle a little more". Go out and run the boat and have fun.

/frank

ahhudgins
02-06-2010, 03:51 PM
I agree with all of the above. Just talk to OJ about what you want and they will help you out, that's exactly what I did. If I remember correctly, both my 87 Powerslot and my 95 Maristar came with a 14 X 18. I believe I ended up getting a 13.7 X 17 OJ 4 blade on both, it's snowing outside so I'm not going outside to check!! I drove an identical 87 Powerslot that already had the 4 blade and it impressed me so much I got one for my boat. When I bought the 95 Maristar I did the same swap with the same results. What ever prop you decide to go with, just don't expect a radical change in your boat. My boat will still struggle if I'm pulling up 2 skiers and I have a boat full of people, not as much if I leave my mother-in-law on the dock.;)

cbryan70
02-06-2010, 05:29 PM
13x11.5 is what he will recommend is my guess. Have it on my 78 and it feels like a different boat with it on