Cleaver cutting

[Tyrone Biggums]

I read out here that there is another member out here with an Aquarius with a 50 tldi running a 11X18 hill cleaver so I ended up buying one.
I can only 5100 rpm at neutral trim. I can trim the motor out more and get 5200-5300 but the angle is excessive IMO.
With only being able to go 1" on pitching, cutting diameter obviously is my only option ?
If I were to try to reduce diameter would the proper way be to follow the original radius to point B, all the way to the root or stop around point A and contour it from that point ? Also will this totally mess up the blade geometry and would pitch be affected?
"assuming" it really is an 18 and get it repitched to 17 and remove 1/4" at a time is it feasible to make this prop work ?


The boat is an Aquarius 50 TLDI 15" with prop shaft about 5mm above hijacker centerline - A whopping 43mph was best I could get monkeying around hydraulic trim.
I did raise the motor one hole up and was able to get 5500 with trim jacked out but having the large tldi motor bracket I'm not comfortable with that mass up so high on transom and would rather put it back at the 5 mm setting... Maybe it's just me but I would rather keep the CG low (yes plenty of pisser water coming out).

[zul8tr]

What is the reduction in diameter with that proposed cut line?

What are you shooting for with the performance, more top end, acceleration, etc.?

Don't know about cleavers (Ron Hill needs to chime in here) but I have trimmed the non cleaver 2 and 3 type blades (for hydro) like you are proposing from A to B. Your cut design will increase rpm but will loose blade area but with all prop mods testing is the only truth. Average prop pitch will not be significantly affected with the cut line you propose.

If you do the cut ONLY blend grind the non push side (facing forward) to get the new sharp edge to be same as the original. You will have to rebalance the blade. To help that once you cut the first blade make a pattern to mark the other blades to be cut to keep same shape and keep near balance. Gram weigh the prop before any cutting. To help with balancing cut one blade and blend grind an weigh note difference from original, repeat with 2nd blade weigh and shoot for same weight difference from 1st blade, etc. You have to be consistent with the grind blend area when doing this.

Then final balance and finish the surface.

[Tyrone Biggums]

I am trying to get some top end out of it and get the rpm's up where they should be and not make a paperweight either.
I made a template of the original blade ear and made the shown proposed cut using that.

It comes out of the hole normally per a cleaver ( minimal throttle fuss) and other than that acceleration is good everywhere else.
The markings I have shown is .250"
I also was wondering about removing some cup and if so, where along the blade should it be cut? Whole length, 70% from blade root?
Once I get the prop close to where it needs to be and knowing I can have an inch de-pitched, it will get sent out to the prop shop for the final cleaning up/balancing. Frank and Jimmy's prop shop is fairly well known down here but they have a crazy 2 week lead time.
If anyone knows of another good shop down in southeast Fl area I would be open to try them.

[zul8tr]

Are you going to cut it and blend grind it?
If so before you depitch it try it the pitch it has may be OK for the engine height you run. I would leave the cup alone at least till after you trim and grind blend it and try it. Removing diameter will free up a prop. What is the existing diameter?

I would cut the blade starting where point B is and make a smooth transition from the remaining curve. Not following your 70% statement.

[Beale Tilton]

Try Jeff Titus in Lake Placid Performance Propellers 863 465 9438

[fs5]

you got to raise the motor right up as high as it will go and still pump water mate. cleavers don't like to run to deep .
if you want the boat to be fast , you got to jack that motor up!
check this site out, plenty of info . most guys just run the carby 50 tohy.
http://www.thundercatinflatable.com.au/forum/forum.php