Reverse Rotation Conversion PCM 351

dareon

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Apr 26, 2010
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3
Hi,

I currently have a 1985 Dixie Superskier 299 with a Ford 351 that I am working on restoring. It is a reverse rotation engine and I was wondering why this is and what could be bad side affects of using forward rotation engine instead. I know I will need a new prop, water pump, starter, distributor, and change the tranny pump direction. (most of these parts need to be replaced anyways and forward rotation is cheaper). One reason for wanting to do this is I am having trouble finding anyone who can grind a reverse rotation roller cam. Has anyone done anything similar or have any reason why one might want to leave it reverse rotation. Perhaps it might affect the handling of the boat?

Thanks
 

jerryjerry05

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May 7, 2008
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18,075
Re: Reverse Rotation Conversion PCM 351

Why are you so sure this is a reverse rotation? I'm just asking as most companies using single engines didn't use them.J
 

dareon

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Apr 26, 2010
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Re: Reverse Rotation Conversion PCM 351

The firing order given on the engine as well as the previous owner saying it is. I have never seen it run but I am 99% positive. I have read the reason is to counter balance the weight of the driver. But the odds of me just having one person in the boat are so low I don't think it will be an issue.
 

Lyle29464

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Mar 10, 2009
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Re: Reverse Rotation Conversion PCM 351

The numbers on the top of your transmission will shed a lot of light on what you can do. If its a 1:1 BW your ok changing stuff. If it's a 1.5 to 1 you can change the input. You can not change the output. Is the firing order on a tag or cast into the manifold? what are the numbers on the prop?
 

Lyle29464

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Re: Reverse Rotation Conversion PCM 351

oops

I did not see the PCM on you post.

If your transmission is a PCM disregard The info I posted about BW.

PCM used a 1:1 and a 1:26 to 1 in a lot of stuff like yours.The 1:26 works with a standard rotation engine and gives you a right hand prop. I am not sure if it works with a right hand rotation engine.

still need to know what your old prop is and some info on the transmission.
 

dareon

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Apr 26, 2010
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Re: Reverse Rotation Conversion PCM 351

The tranny is a 1:1 BW. I don't really have any info on the prop other than its on there and it will make you go forward when spinning clockwise looking from the rear. Any thoughts on how changing the direction might affect the handling/balance of the boat?
 

zbnutcase

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Sep 19, 2009
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2,055
Re: Reverse Rotation Conversion PCM 351

Stick with a flat tappet cam.
 

Lyle29464

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Re: Reverse Rotation Conversion PCM 351

The tranny is a 1:1 BW. I don't really have any info on the prop other than its on there and it will make you go forward when spinning clockwise looking from the rear. Any thoughts on how changing the direction might affect the handling/balance of the boat?

Think your right about the rotation. I have never seen one like that. The right hand prop lifts the right side of the boat just about enough to offset one person at the helm. Not much can be moved to help out. You will need to use your tabs a bit more. I would check out the old cam and see what it looks like. Are you aware of the limitations on the cam? The Rv and truck will not work with your rotation so a marine grind is as far as you can go. If you do find a shop that will make you one be sure to read up on reversion.
 

haulnazz15

Captain
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Mar 9, 2009
Messages
3,720
Re: Reverse Rotation Conversion PCM 351

I guess I don't understand WHY you would want to change it from reverse rotation to standard rotation. There's nothing wrong with how it was designed, and you can squeeze 300+HP out of the 351 with either setup.
 

chriscraft31

Seaman Apprentice
Joined
Apr 19, 2010
Messages
33
Re: Reverse Rotation Conversion PCM 351

My father repowered a boat years ago with a reverse rotation engine, that was because the local crusader dealer sold the standard rotation from the twin engine set, and made him a deal on the reverse rotation. The boat handled great, we wore that new motor out over 20 years or so
 
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