reverse rotation engine

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Norris
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reverse rotation engine

Post by Norris » Tue Aug 24, 2010 8:38 pm

I am going to pull the ls7 motor out of my boat and replace it with a 632 big block, (one of our BluePrint "Pro Series" engines). I really screwed up
when I speced this boat as I made it a gear box boat with a left side driver, and she rolls over pretty good when I am by myself.. I am seriously considering making the 632 a reverse rotation motor and keeping the stinger, thereby throwing the torque roll opposite the driver,,, The cam, the seals, the starter are not a problem, dan at stinger doesnt exactly reccomend it, but sees no reason why it wont work as far as the gear box goes, (they have taken more punishment than I have planned). Just wondered what anyone thinks about doing it this way,,, I am also going to go from the 4 blade S to 4 blade R as i have been told the torque roll is less with the Rs... Speak up... thanks norris

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Re: reverse rotation engine

Post by CULTURED REDNECK » Tue Aug 24, 2010 8:56 pm

Contra-rotating props. Problem solved...

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Re: reverse rotation engine

Post by AirHog » Tue Aug 24, 2010 9:13 pm

Norris:

My suggestion is its easier to move the driver over to the other side than reverse the engine. We used to build boats years ago where one engine had a counter rotation. This was before "full throttle reversing" transmissions. Got many calls from mechanics trying to figure out why a starter did not work, or an alternator failed.... or why it wouldn't run after a complete tune up....

There are several problems with a counter rotation engine.... 1. When your starter goes bad, no one will have one.... if you need a starter drive no one will have it in stock 2. Your alternator will need a reversed fan to cool it... you won't find a replacement when you need it. 3. Lots less choices on things like cams when running a counter rotation engine. 4. People tend to take for granted that all motors rotate the same direction, so if someone pulls off spark plug wires, they tend to put them on wrong.... Had a mechanic pull all 8 pistons out of a counter rotator and put them in notch forward... his mistake was he assume all engines are the same... its a bad rattle when you put them in "backwards".

If you do change it....
Your timing chain cover will need to be a reverse rotation so the timing marks will read correct. Your pistons will need to be put in "backwards" because the crank will be rotating "backwards"... Oil seal needed is for a reverse rotation engine. I don't know much about your engine, I don't know if your oil pump and oil system will be happy running backwards...

Do you think that the fact its an oddball will effect the re-sale? Just a question.

Thanks, and good luck...

AirHog.
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Norris
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Re: reverse rotation engine

Post by Norris » Tue Aug 24, 2010 9:27 pm

yes it would be an oddball, but most folks around here have never even seen an airboat, let alone know what normal is,, I would start out by buying two starters, Keep one for a spare, out in the open the alternator doesnt care what direction it turns, so that is how I am looking at it.. you are right though this would be a morphidite vesion, but in an area where every airboat is unique, and I am in the motor business,,,, maybe it is ok. I respect your opininion and I will definetly consider it over the next couple of days. Keep it coming..

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Re: reverse rotation engine

Post by airboat4fun » Tue Aug 24, 2010 9:29 pm

instead of a gear box, what about a beltdrive?

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Re: reverse rotation engine

Post by JUNIOR480 » Tue Aug 24, 2010 9:31 pm

just seem like a lot of work for a simple cage fix and even with the seat moved over to the other side its still going to roll..we have a 14 foot boat with a 632 on also i can have two men lean of the right side and when you romp down on her she coming over no matter what...j.m.o
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Norris
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Re: reverse rotation engine

Post by Norris » Tue Aug 24, 2010 9:57 pm

I have my gauge panel pointed to the left, and a brake and throttle on the left side, so there would be some stuff to redo, I have yet to build the motor, will do that in the next week or so,, couple seals, a starter for $120, instead of 80.00 or 100.00 and a cam for $100 dollars more, Will redrill the rod throws my self.. so the motor part to make is reverse is maybe 250 more than normal. Compared to reworking the operators stand.. My prop is shot anyway from squeezing the cage under a low bridge...

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Re: reverse rotation engine

Post by flying fish » Tue Aug 24, 2010 10:13 pm

Norris
Why the 632? I would have thought the 480ish cube LS would have been all that?
Will the extra torque from the 632 make up for the weight difference, and will the 632 perform better in comparison?

Truly. Why the 632?
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Re: reverse rotation engine

Post by calbrigsr » Tue Aug 24, 2010 10:15 pm

CULTURED REDNECK wrote:Contra-rotating props. Problem solved...
I agree with CULTURED REDNECK, with one set of props going one direction & the other set going in the opposite direction, it should cancel out most of the roll.
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Re: reverse rotation engine

Post by Norris » Tue Aug 24, 2010 10:34 pm

I like to run what we sell, We just launched the "Pro Series" chev engines under the Blue Print label, It is kind of in conjunction with World dropping out of the engine market, we are using Bill Mitchells blocks and a lot off his input on designing these engines. They are listed on the Jegs website now, although we are just starting to deliver...The LS 482 was a good shop project and I will freshen it and sell it for cheap,, (probably around 12,000$$ with carb and ignition and a fesh dyno printout. My boat has never been right, I am changing the motor stand and rigging in the next month in prepation for the new engine, after that I am going to give it to my son in laws and probably have Wade Hammant build me my dream boat this winter.....

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Re: reverse rotation engine

Post by flying fish » Tue Aug 24, 2010 10:55 pm

I have seen your 632 piece perform with 4 S's and a 2.6 gear. Want to turn? Just stand her completely on her side and go for it. Wow! Pretty cool from 50' away. Your 632 was a real nice addition to the GTO boat -HAMMERTIME- :)
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Re: reverse rotation engine

Post by Norris » Tue Aug 24, 2010 10:59 pm

Thanks

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Re: reverse rotation engine

Post by Waterthunder » Tue Aug 24, 2010 11:00 pm

Norris I would recommend moving the driver and controls. Isn't the Stinger a helical gear and turning it in the opposite direction other then how the gear was designed to be turned load the teeth on the other side and cause a strength issue and maybe an oiling problem? Also I kept quite ( people get mad when you make suggestions anymore) but a main problem is your engine stand no matter what you do it's gonna torque roll real bad unless you go with a counter rotator.
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Re: reverse rotation engine

Post by Norris » Tue Aug 24, 2010 11:11 pm

Dave, or anybody else, if you know what I need to change tell me. I have had this boat for 2 1/2 years and it has never been right. I have posted on this webiste 3 or 4 times looking for advice. Right now our plan is to run the motor stand angle iron forward to connect to the 3rd forward jack in an effort to support the hull and hold it straight and keep it from twisting or drooping or what ever it might be doing. My boat is proof that that you can have great parts,,, Hull, motor, gear box etc,, but the guy putting it together can screw it up with the rigging and design, (partly my fault). I am about to tear this baby down to the webbing if you have suggestions on what to change speak up... I need the help!

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Re: reverse rotation engine

Post by Waterthunder » Tue Aug 24, 2010 11:13 pm

Give me a call Wednesday or PM me your number I would like to talk to you about a few things. There are a few things you can change that will drastically help with your roll. I would rather talk to you about them over the phone.
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Re: reverse rotation engine

Post by Waterthunder » Tue Aug 24, 2010 11:38 pm

I see this all the time when one guy builds a hull and another rigs it and then someone else does the prop and gear ratio. Very few people can actually set up a new boat right. The more people who are involved the less of a chance you have of getting it right. Man I wish there was a way you could test run my Hammant and get an idea how they feel when it's all mathced together.
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Re: reverse rotation engine

Post by johnnybeeegood » Wed Aug 25, 2010 7:50 pm

Would'nt the intake and exhaust be backwards , I run a MACK motor backwards one time and the exhaust was coming out of the intake?

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Re: reverse rotation engine

Post by Waterthunder » Wed Aug 25, 2010 8:23 pm

You usually go with a gear to gear chain and a reverse grind cam. The water pump, starter, cam and alternator must be changed and in some cases the windage tray, oil pan and even cranks due to counter weights.
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Re: reverse rotation engine

Post by johnnybeeegood » Wed Aug 25, 2010 8:30 pm

Oh, OK, I see how it would work like that.

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Re: reverse rotation engine

Post by hammertime » Thu Aug 26, 2010 9:39 pm

Norris you thought I was backwards for my steering, you will really be backasswards with an engine running the opposite way. ha ha

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