Do 5 blades break more drives ?

risingsun · 09-24-2009, 08:29 PM

Ive broken a few drives in my day with my boat,a single drive. broke 1 with a 4blade and another with a 5 blade. my buddys single engine broke 3 drives with a 5 blade so tried a test, I took that prop and gave him a 4blade and he hasnt broken yet. Are there any big power singles or twin engine guys who think 5s break more drives then 4blades . Another ? I have is 1.36 stronger then 1.5

26 REDLINE · 09-24-2009, 08:48 PM

Quote:

Originally Posted by risingsun

Ive broken a few drives in my day with my boat,a single drive. broke 1 with a 4blade and another with a 5 blade. my buddys single engine broke 3 drives with a 5 blade so tried a test, I took that prop and gave him a 4blade and he hasnt broken yet. Are there any big power singles or twin engine guys who think 5s break more drives then 4blades . Another ? I have is 1.36 stronger then 1.5

The Maximus props are the hardest on the drives IMO over 600hp, the 5 blade has less slip and more surface area, although I run a 4 blade but have over 1000hp and 1000lbs of torque so me breaking drives is because of the torque of the engine I will say that if I ran a 5 blade all of the time I would go through drives quicker

Also a big factor is how you run the boat, if you hammer it out of the hole are fly the boat nothing but a #6 will work, and even the 6 will give after some time. What is your buddy running for power, weight of boat, cat, or V, and does he drive it like he stole it...maybe you are a better driver...

Boomer35 · 09-24-2009, 08:50 PM

i might be wrong, but i think no matter what the drive, the more blades, the harder it is on the drive

risingsun · 09-24-2009, 09:24 PM

Quote:

Originally Posted by Boomer35

i might be wrong, but i think no matter what the drive, the more blades, the harder it is on the drive

A boat shop put imco nose cones on my other buddys 38 cig with XRs and he couldnt get on plane with out blowing out his props, so of course they sold him new 5 blades and now he's broke 2 lowers. The single engine friend runs 1300hp in a 28' Nordic with a Bmax. He runs a 1.36 ,30p lab 4blade. the drive breaker was a p5x 27p. The boat shop said they talked to some drive guys and I was full of it.

Coolerman · 09-24-2009, 10:06 PM

a 5 blade will have less vibrations though and be smoother which can help drive life.

The biggest thing though for your drive is being good on the throttles.

articfriends · 09-25-2009, 01:18 AM

I believe 5 blade props,especially the maximus,make drives fail much quicker than 4 blades. I ran a max worx billet prop shaft for over 300 hours with various motors in my boat including the current package which also makes over 1000 hp and 1000 ft lbs of tq,I sheared off that prop shaft almost immediately testing a 5 blade maximus prop, and that was 3 years ago when I only had 950 hp/ft lbs of tq. My current slip is between 15-20% depending on my speed,when I got it below 10% parts started breaking almost immediately,Smitty

Griff · 09-25-2009, 02:39 AM

I'm with ya. Higher propslip numbers and being easy out of the hole will help keep drives alive. I had about 17% on my 28 Pantera with 550+HP. the boat was 5200# dry and most of the time I was running at 6000-6500# with fuel and people. The Imco upper had over over 300hrs on it and the lower had almost 400hrs on it. I was running a Bravo1 4 blade.

Beak Boater · 09-25-2009, 09:01 AM

The 5 and 6 blade props were developed to run in high X demnisions in aireated water where the normal 4 blades would not lock up or the slip numbers could not be improved anymore. If you are running 10-12% slip on a V a worked 4 blade is probably you best all around prop. Usually on a boat that is set up properly with a 4 blade, you will gain mid range mph and lose top end mph when going to a 5 blade. Remember your prop is like a clutch in a car, you need some slip to get on plane, and accelerate, since you dont have any transmission that has multiple gears. 5 blades running on standard length gearcases, will lower slip, increasing stress on the drive.

Biggus · 09-25-2009, 10:16 AM

It's a double edge sword. Low slip can be very hard on shafts and other components. High slip can really shorten gear life from loading and unloading (gear chatter) This can be tough on forged gears, they tend to pit heavily, eventuallly failing causing much damage.

A stock Maximus has a lot of disc area. Out of the box they are 15 5/8" dia and grip pretty hard. They really do not work well on anything box stock, you are pretty much just buying the raw material. Brett from Bblades does a great job with the Maximus as he labbs it to fit the application.

Kurt

SkiDoc · 09-25-2009, 06:24 PM

I've got labbed Maximus props on the DCB. At the Lake Cumberland Poker Run I made an error with the throttles and didn't get off them enough after flying off a big cruiser wake. Upon reentry the prop instantly hooked up and you could really feel a snap in acceleration. I cringed because I knew I had to come close to popping drives. I've got IMCO extension boxes with torsion shafts. I think that helps some. Bottom line is that those props hook up hard. They do perform well though. Great mid range, will stay on plane at 23mph, great for skiing. I've got 4 blades but the 5 blades stay on the boat.