More Horse Power

Paul Fox

Recruit
Joined
Jun 30, 2002
Messages
2
I am currently in the process of pulling down my 1983 235 Evinrude, and am wanting to extract some more horse power out of it.I was wondering if anyone would have some helpful tips :p
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: More Horse Power

As long as you have it apart it's easily converted into the XP/GT style motor if you have a good machinist. As we've stated before, you still have the same bore/stroke and gear ratio. If your set up is at optimum now and your boat responds well to slight power increases, you may see some improvement. However, if you are set up to turn 5500 or less, you may not see a change. You may gain more with set up once you get going again.<br /><br />No matter what you do (and can still use 87 octane) it will never have the torque of a looper.<br /><br />Why does it need rebuilding anyway?<br /><br />Good luck!
 

Paul Fox

Recruit
Joined
Jun 30, 2002
Messages
2
Re: More Horse Power

Thank you for your replys guys!!<br />Dhadley in response i am pulling down the engine simply to check the internals (as you can imagine they would be getting a bit long in the tooth by now) and also to get more horse power as the motor is stock standard at the moment.I do have a good machinist and am wondering where to find out what conversions are required for an XP/GT engine.Also what do you mean by looper??( the loop charged versions) :confused:
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: More Horse Power

To convert it to an XP/GT all you need is the scalloped pistons. Then machine the by-pass area to match, square the ports and use XP/GT heads. The pistons are terribly expensive but you can cut standard type piston to match. The XP/GT motrs had fiberglass type reeds that did not last very long. I prefer the Boyesen reeds.<br /><br />Once again -- if your set up is not maxed outnow you will see very little, if any, difference. If your boats hull is not of a performance type (pad bottom or some version of tunnel) you may see only small improvements.Tell us about your set up now. Top RPM's, true speed, size - type and style of prop. Tell us about your boat. If you have an Allison you can expect a decent return on investment. If you have a Bayliner I doubt you will see any change.<br /><br />Let us know!
 
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