Rotator Gear Box Ratio Change?

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nebraskaairboater
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Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Thu Jun 30, 2016 9:59 am

Any one know if Classic/Panther will change the ratio of a Rotator from 2.12 to 2.37? Or any other box manufacturer sell the replacement gears to change it myself? I have sent several emails with no response from Classic. (I know I should call but not to that point as of yet) I'd like to get enough gear to turn a 3 blade 80" S prop. My 2 blade right now set on 2 turns 4300 rpm WOT.
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby Waterthunder » Thu Jun 30, 2016 10:09 am

Usually the most cost effective way to go is to sell your old box and purchase a new one. For what you can sell old one and then buy what you want is about the same as sending your old one out and having the ratio changed.
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Re: Rotator Gear Box Ratio Change?

Postby Deano » Thu Jun 30, 2016 11:00 am

x2 , experience has shown over time that what Dave says is exactly the case. The sense that a Classic upgrade would make monetarily, is even less given your locale and the associated shipping costs.

Were it me, I would sell that box local and call Shane and press him for a 'locals discount' on a new ballistic. 8)
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Re: Rotator Gear Box Ratio Change?

Postby SWAMPHUNTER45 » Thu Jun 30, 2016 11:26 am

I doubt you will find a better deal than a new Rotator 2.37 for $2,549 plus shipping!

That's a great price in my opinion

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Re: Rotator Gear Box Ratio Change?

Postby Waterthunder » Thu Jun 30, 2016 12:14 pm

Dam 2550, Im sure you can sell your old one for 1900 or more and I bet they want more than 550 to swap ratios. Then you only need to spend shipping one way.
THE PROOF IS IN THE PROP!

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Re: Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Thu Jun 30, 2016 12:25 pm

thanks for the advice guys... I'm thinking ahead for a winter (off season for us) project. My plan is to also overhaul my engine since i'm still running on the stock bottom end and possibly moving up to 60 over 10 to 1 pistons and bigger valves in the heads. I'm not sure if that will give me the power to turn 3 blades efficiently with the 2.12 or not. I'm afraid of getting to that in-between area where I have too much for 2 blades but not enough for 3 then I have to do something with gear ratio. More food for thought on my end with the gear changes.

Dan
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby scottyroll » Thu Jun 30, 2016 12:46 pm

nebraskaairboater wrote:I'm afraid of getting to that in-between area where I have too much for 2 blades but not enough for 3 then I have to do something with gear ratio.
Dan


Dan, that is exactly what I was thinking.

Also, I switched to a 3 blade "non S" prop and really enjoyed better performance over-all even though I lost pitch, of course.

The S blades just don't perform well in a 2 blade configuration on gear reduction unless you really turn them up IMO.

Waterthunder, didn't you say a long while back that they weren't any good except for racing?
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14ft Laser/6.0 LQ4/2.37 Rotator/3 Blade "K"

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Re: Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Thu Jun 30, 2016 1:41 pm

I've thought about a 3 blade old style R but don't' want to turn my motor more than 4500 to 4800 max and not sure how the R does that slow. Wish I could try one but not many gear reduction around me... my family all run belt drives. My dad has a 3blade r on his Olds motor with a 2 to 1 belt only turning 4K max and seems to do ok but my 2 blade S seems better to me over that.
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby GOTTHEITCH22 » Thu Jun 30, 2016 3:16 pm

I asked them if they could change mine if I brought is to them they said no , Have to buy a new box .
I've got my 2.1 on a blue print 383 stroker with a 3 blade 80 inch whirlwind prop . Keep mine pitched enough where it will only turn 4700 .

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Re: Rotator Gear Box Ratio Change?

Postby Waterthunder » Thu Jun 30, 2016 5:59 pm

I will keep it short KINDA exhausted from the discussion. I would run a 2.68 or 2.55 WITH A 82'' PROP set your pitch to turn 5,200 to 5,600. In my opinion 5,400 with a 2.68 ratio is far less wear an tear on a motor than a 2to1 or 2.38 turning 4,900. Not even mentioning True thrust results! I have seen and proven this a hundred times you almost always see a lower cruising RPM because your making substantially more thrust at cruise RPM's.
THE PROOF IS IN THE PROP!

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Re: Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Thu Jun 30, 2016 10:20 pm

Does that theory prove true for the Cadillac engine as well? My cam runs out at 4800 according to MTS. Thanks for all the info guys.
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby Waterthunder » Fri Jul 01, 2016 9:47 am

I wouldn't even run a 2.38 on a Caddy. You have a low RPM torque motor that has a RPM limit. When you have certain limiting parameters the answers are different. Remember there is a tip speed area you want to be in and to achieve that area and keep the engine below 4,900 you cant achieve either with a 2.55 or 2.68 and I wouldn't even recommend a 2.38. Your not going to see much of a torque multiplication gain between a 2.12 to a 2.38 ratio. Now if that Caddy could turn 5,200 I would try a 2.38 but that ofsets what the Caddy does best!
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

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Re: Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Fri Jul 01, 2016 11:14 am

at what point are the S blades over pitched and just beating the air? There's a guy here that runs a 3 blade set on 1 and it pushes ok but that seems light on pitch and mine has a completely different sound than most as it is a real low tone like maybe it's pitched too much but pushes really good on the ground. I'm at the 2 mark lined up with the seam on the fixed half of the hub turning to 4300 rpm. Engine is completely stock bottom end untouched from out of the car. I have the shaft rocker system and heavy springs, #10 cam from MTS, Cloyes Timing set, and aluminum intake.
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby Waterthunder » Fri Jul 01, 2016 12:38 pm

I have never seen a 2 blade S work very well. I ran one when the 1st came out. I found in the end a 3 blade R performed everywhere better. Sounds like you combo is pretty close what happens when you turn it 4,500
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

http://waterthunder.com/
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Re: Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Fri Jul 01, 2016 2:20 pm

haven't given that a try yet. I'll have to reset it this weekend and give it ago.
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby warrior-p » Mon Jan 02, 2017 1:20 pm

I got a ballistic 2.3 for sale
18 x 8 TEXOMA AIRBOAT, ZZ540 engine, 2.38 BALLISTIC DRIVE and an 82" 4 blade Whirlwind Whispertip EX prop

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Re: Rotator Gear Box Ratio Change?

Postby SWAMPHUNTER45 » Tue Jan 03, 2017 6:44 am

I disagree with some of what Waterthunder has said on the stated gear ratios for a Cadillac application.

If your 472/500 platform is stock the 1.53 to maybe if cautious 1.71 are your safest bets.

A lightly modified valve train will live at 1.71

A shaft system with one piece valves the 2.1 is an option but a stock cam may not make it worth much gain over the 1.71.

When upgrades are more extensive going above to a 2.1, 2.37 or 2.68 are relevant to your engine upgrades, prop selection and overall use.

A roller modified 500 built right on a 2.37 is a beautiful thing!

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Re: Rotator Gear Box Ratio Change?

Postby 406 JAMIE » Tue Jan 03, 2017 9:14 am

SWAMPHUNTER45 wrote:I disagree with some of what Waterthunder has said on the stated gear ratios for a Cadillac application.

If your 472/500 platform is stock the 1.53 to maybe if cautious 1.71 are your safest bets.

A lightly modified valve train will live at 1.71

A shaft system with one piece valves the 2.1 is an option but a stock cam may not make it worth much gain over the 1.71.

When upgrades are more extensive going above to a 2.1, 2.37 or 2.68 are relevant to your engine upgrades, prop selection and overall use.

A roller modified 500 built right on a 2.37 is a beautiful thing!



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Re: Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Tue Jan 03, 2017 9:33 am

I have been running the 2.12 on my caddy for 5 years now (I think it is) with a shaft rocker system, small block chevy valve springs, and MTS #10 cam. Those along with a cloyes timing chain replacement are the only upgrades I have done and knock on wood, no problems yet. I did order a 3 blade hub and 3rd blade and I'm more happy with it now. It sounds like the other boats now and pushes a little harder. I'm turning it to 4000 engine rpm set on about 1.25 I'd say on the pitch. Less vibration and lower cruise rpm. This fall I had my boat loaded with 9 people (4 kids) and drove everyplace I would have alone and it pushed on our sandbars pretty good and still cruised at around 3200 rpm. When I'm alone my cruise is down around 2500 rpm in skinny water its down to 2000 or less. My next upgrade will be the heads if I ever get to that point. Otherwise I am happier with the 3 blade S over the 2 blade and my boat pushes just fine.
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby Deano » Tue Jan 03, 2017 9:52 am

Glad to hear that you went that route as opposed to the gearbox alternative.
What you did was the better logistical option, both cost and performance wise.

Considering what you have now and how it runs, I don't think that the expense involved with
playing the head game would be justified for the small amount of real difference it would make.
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Re: Rotator Gear Box Ratio Change?

Postby nebraskaairboater » Tue Jan 03, 2017 10:07 am

That was my thoughts as well. At this point it does everything I want it to do and seems to be reliable for me so I really don't want to push it any further. If it gives me problems then I will upgrade as I go. I put a little video of my boat pulling off the sand and over a small sandbar in my gallery but can't figure out how to add it to my post.
Dan Porter, Jr.
Fremont, NE
16 x 8 1971 Flat Bottom Fiberglass Hull / 500 Cadillac/ 2.12:1 Rotator / 80" 3-Blade Sensenich S

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Re: Rotator Gear Box Ratio Change?

Postby SWAMPHUNTER45 » Wed Jan 04, 2017 8:52 am

If you acquire a set of properly ported, radisused and relieved heads with undercut oversized valves you will most likely see a solid gain. In an 8.5:1 engine not so much as the higher compression ratios. Sounds like it is doing everything you want it to so if that's the case enjoy the slide.


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