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View Full Version : 22 rolling over---need prop



thehow33
05-16-2010, 08:51 PM
my 22 was finally put together and then ended up having some motor issues, which seem to be figured out now.
However, I ran it last weekend with a 29p 4 blade which I know is way too much prop for my boat, but I figured I could use it to get the motor running smoothly. While at full throttle (3900rpm) going about 50mph the boat rolled way over onto its port side and tried pulling hard left. (scared the crap out of me, almost literally) plus the wife won't get in it until its figured out.
This week I tried a 26p 4blade which gave me 55mph at 4100rpm's. However, the boat tried rolling over on its side again. I noticed that it happens between 3000-4000rpms. Also, it only happens when the wind is blowing into the starboard side. This even happens when the drive is all the way down or trimmed up.

I'm just wondering if anyone else on here has experienced this and what helped.

Lastly, I would like to try some 3blade 24-25p props at AOTH if anyone could help I would greatly appreciate it.

gcarter
05-16-2010, 09:03 PM
I had a similar experience in my former Minx at AOTH about five years ago.
I had four people in the boat and I was running a three blade labbed 25" cleaver.
It did it several times between 3000 and 4000 RPM.
My solution was to not use that prop again.
I eventually settled on a Hydro Q4 of 22" and it was the best prop I used on that boat.
You seem to have an unusual ratio. The speeds seem to be very low for the engine speed. Do you know what your outdrive ratio is?

thehow33
05-16-2010, 09:06 PM
I had a similar experience in my former Minx at AOTH about five years ago.
I had four people in the boat and I was running a three blade labbed 25" cleaver.
It did it several times between 3000 and 4000 RPM.
My solution was to not use that prop again.
I eventually settled on a Hydro Q4 of 22" and it was the best prop I used on that boat.
You seem to have an unusual ratio. The speeds seem to be very low for the engine speed. Do you know what your outdrive ratio is?

I don't know the ratio. Do you really think picking up 5mphs on only 200rpm's is not a good ratio. I was really hoping to hit 70mph
Also I should add I have an IMCO shorty and I have tried a 25p cleaver which I couldn't even get on plane.

osur866
05-16-2010, 09:08 PM
I'll be arriving late on WED. I have a 25p M+ you are welcome to try, just look me up STEVE

thehow33
05-16-2010, 09:15 PM
I'll be arriving late on WED. I have a 25p M+ you are welcome to try, just look me up STEVE

That would be great...Same here leaving chicago area with trueser's son matt at around 4pm. about a 7hr trip so probably not getting there till pretty late. drive safe.

gcarter
05-16-2010, 09:34 PM
Try this prop calculator;

http://go-fast.com/Prop_Slip_Calculator.htm

Plug in some numbers and see what's happening.
Assume a 1.5 ratio, ideal prop slip should be around 10%.

mrfixxall
05-16-2010, 11:02 PM
Try this prop calculator;

http://go-fast.com/Prop_Slip_Calculator.htm

Plug in some numbers and see what's happening.
Assume a 1.5 ratio, ideal prop slip should be around 10%.


George i borrowed him 2 of my hydro's Q4's..the 26p he said it wanted to do the same thing but a its a little better then the 29 he has..also gave him a 22p Q4 but it was a lefty and he didnt try it yet..

Im thinking he is in his max torque range and theirs alot of bite on the prop and with it being a stern lifting prop it wants to drive the nose over..

Morgan's Cloud
05-17-2010, 06:50 AM
I hate it when you go through all that work and then that happens !

In may case a simple switch to a DP outdrive fixed it .. :wink:

MOP
05-17-2010, 07:25 AM
While this may very well be a prop issue there is another possibility, this may not have any bearing but worth checking into. Being as it happened with two different props has me thinking the that there may be a problem with the shuttle valve for the power steering. Have you greased the fitting on the valve to ensure full free travel? With the engine off move the steering wheel slowly from side to side and observe the valves action, the ram should not exhibit any jerky motion what soever and travel completely to each end of the slot. Once sure it is moving freely I would borrow a manual and go through the centering adjustments. Many times just greasing the unit and working the wheel back and forth a few times witht eh engine off gets it working smooth again, that seems to be one of the overlooked fittings but quite important.

Phil

19donziz29
05-17-2010, 09:01 AM
He has full hydraulic steering on the boat. MOP would this issue your talking about pertain to full hyd steering? I was in the boat yesterday it's definately the 4 blade props giving way to much stern lift. The bow never seemed to lift. He also has an IMCO shorty. I think a 3 blade 25p Mirage or Mirage + is what he needs. Also hopefully he'll get a chance to try a Turbo out at AOTH. Boat runs great, it's going to run good with the correct prop!
Matt

Cuda
05-17-2010, 09:34 AM
I ran a 3 blade 24" Turbo prop on my 22C. I had plenty of props around, and it worked the best. A cleaver prop won't make it torque to one side as much. I ran a cleaver on my Minx. They are dirt cheap.

oledawg
05-17-2010, 09:52 AM
Interesting thread, as I am trying to figure out the same thing. 27P Mirage runs 65 mph at 4400 rpm WOT, 23P cleaver runs 5000 rpm at 70mph but cavitates like crazy getting there. Hadn't thought of the "rolling", but the cleaver "rolls" much less. And you guys are right, the "rolling" is at lower rpm, once up above 50mph it is solid with either prop. Thinking a 25P Mirage or Mirage + may be the best.

VetteLT193
05-17-2010, 10:13 AM
how short is the shorty?

If you went up more than an inch I'd go with something that has serious bow lift.

Also more blades = more stern lift.

The Quad IV is a stern lifting prop. the Quad IV-X is the bow lifting version. Either the IV-X or a Bravo with added cup would probably fix it. The Quad IV works well on 22 with 1" up X and trimmed out so I am guessing you are 2" up from stock.

Cuda
05-17-2010, 12:35 PM
Interesting thread, as I am trying to figure out the same thing. 27P Mirage runs 65 mph at 4400 rpm WOT, 23P cleaver runs 5000 rpm at 70mph but cavitates like crazy getting there. Hadn't thought of the "rolling", but the cleaver "rolls" much less. And you guys are right, the "rolling" is at lower rpm, once up above 50mph it is solid with either prop. Thinking a 25P Mirage or Mirage + may be the best.
You have never felt cavitation like my surface drive Formula. I'd firewall the sticks, it would cavitate like crazy, then you would feel it "catch" and you were backing off the sticks quickly. If there ever was a boat that should have been called Slingshot, that was the boat. It ran a 26" pitch and 17" diameter props I believe.

yeller
05-17-2010, 01:43 PM
I'd definitely try a 3 blade. Although not exactly the same, I did have somewhat similar problem running a QIV on my boat. Switching to a 3 blade didn't eliminate the problem but it certainly reduced it. You should also try the lefty. When it comes to handling quirks, try anything and everything you can get your hands on (regardless of what worked and didn't work on someone else's boat).

thehow33
05-17-2010, 05:37 PM
Thanks everyone for all of the input, you gave me a lot to think about.
Yeller you brought up a good point that I was thinking about. If I try a lefty would it eliminate the rolling over due to it rotating the opposite direction of the motors rotation. What are the downsides to doing this? Would it hurt the drive since all of the gears have worn in one direction already.

I have a 2" imco shorty....does anyone know which hulls had the raised X-dimension?

MOP I have full hydraulic steering.

Oledawg how is your boat setup? I think my boat is setup similar to yours.

yeller
05-17-2010, 06:17 PM
I can't see how switching to a lefty would hurt the drive. You'll just be relieving pressure from the current side of the gear teeth and putting it on the other side of the teeth.

Although I have seen people post it does, I have also seen people post that it doesn't.

VetteLT193
05-17-2010, 06:57 PM
Thanks everyone for all of the input, you gave me a lot to think about.
Yeller you brought up a good point that I was thinking about. If I try a lefty would it eliminate the rolling over due to it rotating the opposite direction of the motors rotation. What are the downsides to doing this? Would it hurt the drive since all of the gears have worn in one direction already.

I have a 2" imco shorty....does anyone know which hulls had the raised X-dimension?

MOP I have full hydraulic steering.

Oledawg how is your boat setup? I think my boat is setup similar to yours.

1987 454/alpha and the Shelby boats were raised an inch. also seems that the 80's small block / alpha boats were raised an inch too.

the lefty wouldn't hurt but I can't say that it would fix the issue or not. I am still putting money on a bow lifting prop vs. stern lifting.

I personally hate the Mirage + with the 1" raised X. blows out like crazy. faster for sure but when getting on plane is a pain being in the boat is simply less fun.

I'm still guessing a worked bravo 1 with more cup or a hydro X will do the trick.

also... I think weight is more of a factor than the gyroscopic force of the engine spinning

thehow33
05-17-2010, 07:10 PM
I have an 88'...when FarmerTx looked at my boat he noticed that the through transom exhaust was cut out for a small block. Also, is it possible that my 88 was actually an 87's hull which has the raised X?

yeller
05-17-2010, 11:06 PM
I personally hate the Mirage + with the 1" raised X. blows out like crazy. faster for sure but when getting on plane is a pain being in the boat is simply less fun.This is why I say to try anything and everything regardless of what I or others others say works or doesn't work.

The M+ on my boat blows out super easy. Barely gets the boat on plane which doesn't seem to be a problem for most people. (My drive is stock height). Titan, on this board has the same year hull, with a -2 shorty and he loved the M+ when I let him try it. Based on my setup, his should have been even worse for blow out, but had absolutely no problems with it. He ended up ordering a M+. I switched to a Tempest Plus. Runs about the same as the M+ but doesn't blow out.

osur866
05-18-2010, 02:23 AM
Keep in mind every boat is different just as each driver drives differently and in different water conditions, a 3 blabe with good bow lift will "probably" be the fastest if the boat likes it and if that is what the driver is after, I run a -2" shorty on an 18 and I really like my heavily worked over M+, I also run a Bravo 1 that has added cup which actually has MORE bow lift than my M+, that I run in certain water conditions, alot is based on mood and what I want to do that day, for all out top end and cruise, my M+ is best so far for my set-up, but I'm always willing to try something new that I haven't tryed, JMO and .02

PS- prop threads, aren't they great? LOL