Cleaver rake

[Forkin' Crazy]

How much more bow lift do you get with a cleaver with more rake?
Example: The 30" Merc cleaver has less rake than the 32" Merc cleaver. As far as I know Merc doesn't make a high pitch raker with no rake. What other manufactor makes one?
BTW Thinking of getting a 32". :O

[Scream And Fly.com]

Paul,
Usually, more rake = more bow lift. It is my observation that the Mercury Cleavers tend to have more rake than most other cleavers. That's one of the reasons I like them so much - they give good stern lift and provide some bow lift as well. If you like the Mercury Cleavers, your best bet is to have Mercury Racing work on it for your specific application. They never let us down, and we just received our 32P Mercury Cleaver from Mercury and ran it this past week for the TV shoot at 115 mph (still had more to go) - no problem!
I have a very high-rake Spinelli Cleaver, but that prop has major work done on it for Formula One use, so it's not a fair example of Spinelli props. It gives a LOT of bow lift though! I'm saving that one for my Progression 22 / 300X that's being built this summer.
Greg:)

[hpron]

Whazz up greg..good to see ya spread some good stuff over here as well...aka Talon Skat 21:(

[Kim Hanson]

Originally posted by Scream And Fly.com
Paul,
Usually, more rake = more bow lift. It is my observation that the Mercury Cleavers tend to have more rake than most other cleavers. That's one of the reasons I like them so much - they give good stern lift and provide some bow lift as well. If you like the Mercury Cleavers, your best bet is to have Mercury Racing work on it for your specific application. They never let us down, and we just received our 32P Mercury Cleaver from Mercury and ran it this past week for the TV shoot at 115 mph (still had more to go) - no problem!
I have a very high-rake Spinelli Cleaver, but that prop has major work done on it for Formula One use, so it's not a fair example of Spinelli props. It gives a LOT of bow lift though! I'm saving that one for my Progression 22 / 300X that's being built this summer.
Greg:)
Let's see picture's or video...Greg!....( . )( . )......You can do it!

[You Te]

I guess you don't like bottom end FC.
You Te

[Forkin' Crazy]

Thanks for the reply,Greg. I was just wondering how much more lift would be generated by the higher pitch cleavers because they have more rake then the lower pitch.
I really don't think that I will need much bow lift. Mid 90's I am running some negative trim with a SRX. I know it makes a good bit of bow lift. I was just wondering how much more bow lift is created by more rake.
BTW I posed the same question on your website, just didn't get a lot of answers, or not the one I was looking for. Looks like this going to be a trial and error type thing.
I was thinking of getting a cleaver from Precision Propeller. Anyone try one of these?

[Forkin' Crazy]

Originally posted by You Te
I guess you don't like bottom end FC.
You Te
There is where you are wrong my friend. ;)
My 27" yammi copy does just fine.
But, I was looking to break the century mark with my antiquated OMC.... LOL! She is 24 this year.....:eek:

[Scream And Fly.com]

Paul,
Remember, Rake and Pitch are not always related. You can have a high-pitch, low-rake propeller. I had a 30P Mazco that had very little rake, and as a result, had very, very little lift to it.
I'm sorry you didn't get the answers you were seeking on Scream And Fly - I didn't see your post :(
Greg

[HavasuDreamin']

Can someone tell me what "rake" is in lamens terms?
Reason I ask is that I have been running a round ear (Mazco RE-3) on my 19' Elim. Daytona/2.4 Merc Bridgeport combo. The prop worked well for me until I took out the two saddle tanks (mounted pretty far forward) and installed one center tank towards the rear. That made a huge difference in the boats attitude. It didn't want to fly before. Now that is no problem.
However, now at the very upper end of the RPM band (7,000+) I develop a porpoise that starts with the passenger side sponson picking up, then letting down, then picking up, then letting down. It starts to get so violent that I have to let out of the throttle before I get to max rpm .....about 7,500. This usually only happens with me in the boat. If I put another passenger up front, it tends to not do this as bad, especially if that person is 150lbs. +
I suppose part of it could be that I (driver) sits on the left side and the prop is RH rotation. But I still should be able to get the porpoise out. Bottom is straight.
I have messed with the trim, postive trim, negative trim. Nothing is working for me. Been thinking about switching to a cleaver since I am running no positive trim at speed. What type of prop would you guys look at. Cleaver, Lightning Et????? What brand. Keep in mind I will probably be buying used since I don't want to fork over $750 for a prop that may not work.

[Forkin' Crazy]

My understanding is the rake is the angle of the trailing edge of the blade inrelation to the propeller shaft.
From reading on the Merc website (I think they have changed it b/c I can't find it anymore) the cleavers up to 30" had almost no rake, and over 30" was like 10 or 15 degrees. This is what I was getting at. How much dif will it make? I guess I worded my question wrong????:confused:
HD, how high are you running your motor? Pad to propshaft?
A cleaver will give you mostly tail lift. Additional rake will give it more bow lift (from what I understand).
Sounds like you may need more setback? If your running positive trim?
Has your prop been worked on? You can have it cupped to make more bow lift.
I am having a little handling problem too. I think it is mainly weight and balance. I have some bags of lead shot that I am going to add as balast in several different places to see if it helps. I think I may have to change for less setback b/c I am running almost negative trim.

[HavasuDreamin']

I am running neutral trim at speed. The propshaft is about even with the bottom of the center pod. I would guess that my setback bracket is about 6"- 8" and my CMC jack plate adds another 6" or so. Don't forget the center pod is not notched on the 19' Daytona, so I have been under the impression that the more setback, the better.
Like I said, I never experienced this porpoising until I relocated the tanks a couple of years ago. Now the tank is at the rear and in the center pod instead of twin saddle tanks mounted forward (near the dash bulkhead). I would think that my issues are weight and balance related.
I would think that by trimming it out, the porpoise would go away. My thinking is that there isn't enough bow lift to carry the nose. But even when I do trim it out, not only does it get scary flighty, but the right sponson still tends to pick up and set back down. :confused:
That is why I am thinking a cleaver to get the back end up out of the water now that the tank is back there. In addition, the boat does like to fly with neutral trim so I don't know how much bow lift I really need my prop to have.
Any thoughts.........I am open to anything.

[HavasuDreamin']

Looks like we lost a couple of posts from the board crash. Thanks for the input FC. :cool:

[AQUAholicSTV2]

Hi Guys.
Most cleavers are about 15 degrees of rake where most choppers are 25 degrees rake. This extra 10 degrees of rake should produce 10 more degrees of bow lift at the same trim angle.
The only high rake Merc cleaver I know of is the 32" pitch and it has about 23 degrees rake.
My buddy's 15 x 30 Spinelli cleaver has 25 degrees rake which makes it holeshot better and give much more bow lift than normal cleavers.
I also had a 15 x 32 Mazco Offshore cleaver, same deal quite a bit more bow lift.
Most Yamaha drag props and copy's too are about 18 -20 degrees rake. The exception being the Powertech Yama-copys.
I have a 29" pitch 4 blade Powertech SCG4 Yama-copy which has 29 degrees rake. More bow lift than any prop I have ever run.
Havasu Dreaming- with a outboard the driver really should be on the starboard side cause thats the side that gets torqued up from the prop rotation.
Also rake can be thought of like pitch on the oppisite axis. Easiest way to see it is how much the blades sweep away from the motor.
High rake means the blade tips sweep far away from the motor. Low rake is like cleavers, very flat blade tips that dont sweep back away from the motor.
Here is my 29" Powertech. Notice how much the tips sweep back ? Very high rake.

[AQUAholicSTV2]

Heres the high rake Mazco on the left, and the normal lower rake Merc on the right.
Notice how much higher up off the floor the tips on the Mazco are ? Higher rake.

[VIKING]

Did you get that in "lamens term" Havasudreamin:D ? I also have a prop problem and this looks like prop class 101 I know I need less bow lift so less bow lift=less rake. Now I just need to get lucky and find the correct prop:eek: Is that correct teach??

[Tom Brown]

Great post, Randy. Thanks. :)

[Forkin' Crazy]

Thanks Randy!:)
What kind of cleaver (brand, etc) would you recomend for a top end prop for a Mod VP style hull similar to a Mirage?
I can run mid 90's now with a stock 29" SRX @ around 7K rpms.
Thanks again!
Paul:D

[Tom Brown]

Originally posted by AQUAholicSTV
Heres the high rake Mazco on the left, and the normal lower rake Merc on the right.
Check out the reflections from the Mazco. The light reflecting off the Merc prop looks to be distorted by surface undulations.
Is that a Lab finished Mazco?

[Scream And Fly.com]

Lab Finished propellers have a directional satin finish, like the prop on the right.
Greg

[STVBOY]

HD
Why do you have 12in of setback on that boat.That could be the reason why you are having handling problems.Most people with that much setback have a heavy boat but yours can't be that heavy. I would change that right away that cannot be right for a daytona.

[HavasuDreamin']

Originally posted by STVBOY
HD
Why do you have 12in of setback on that boat.That could be the reason why you are having handling problems.Most people with that much setback have a heavy boat but yours can't be that heavy. I would change that right away that cannot be right for a daytona.
Well, Dick Sherrer Marine set it up for me. Dick use to run a 19' Daytona back in the mod vp hay day. Remember that this hull is set up for a jet pump. There are no notches in the pod or in the tunnels. Therefore........the idea is to get the motor away from the hull so that the prop is turning clean "undisturbed" water. I really think some simple weight distribution and/or another prop would help me out tremendously.
Aquaholic...........great post. And yes viking, I know understand what rake is in "lamens" terms. :)

[VIKING]

Hey havasudreamin I just wanted to let you know with all the tect talk and you said lamens term I was just jokin around. Didn't mean anything by it. glad to here you got hooked up though:D :D see ya . Kurt

[Tom Brown]

Rule #1: Never let a jet guy near an outboard.

[VIKING]

This looks like a set up, but I'll ask. Hey Tom Brown what is rule #2:D

[Tom Brown]

Originally posted by VIKING
Hey Tom Brown what is rule #2:D
Never let a stern drive guy near an outboard. :D

[VIKING]

Tom!! I Know FOR sure, do not let a inboard guy take your boat out for a spin. there are to many things to do. Jake plate,tilt and OH YA TACH.`:yuk:!!! Is that #3$$$$!! Thats why I bought a another 200 Merc..

[HavasuDreamin']

No worries Viking. No offense was taken. :cool: