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Discussion Starter #1
i just bought a 91 750 motor for my 89 gsxr complete for $500cdn. the mechanic has suggested having the head ported and the cams radiused(?) for another $500. labor to re/re the motor is another $250.

is porting the head worth it for street use? i know it will help breathing, but what does that translate into unsable power and where on the powerband? i'm not expecting 1100 power but...

ben
 

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unless, you are going to do major work to the engine it is not worth it, and I would be leary of a 500$ porting job, sounds fishy to me, and the"radiusing" of the cams he probably, meant degreeing them, and again for 500$ if you want cams talk to http://www.aperaceparts.com they can help you, a good head job will set you back around 1200$ to start, but you don't want a new head to be beating on the old stuff down stairs, if you want more pwer be prepared to spend time and money, it is better to take the time and do it right than half ass it and break something
Karl
ps. get a manuel and tear the engine down your self and save a few bucks

oh yeah I just remembered if you do mes with the cams, watch out for the valve retainers in the head the 91 has shim stlye valves and you should replace the retainers in the head too with the cams, but talk to APE they are knowledgeable

[ 10-04-2001: Message edited by: KJ1 ]
 

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Discussion Starter #3
motor is apart now... some bad news, but expected:

- helicoil swimming in oil pan... drain plug is stripped
- cams are showing signs of pitting
- leakdown shows average of 6% loss, worst one is 16%, but i'm told it will free up
- oil cooler is toast

otherwise it looks okay... all the electrical is intact with the black box, the pan was clean (other than the helicoil), it shows signs of being properly pickled before storage 3 years ago, and the tranny screen is clean too.

i'm not going to do anything myself unfortaunately. dragging a motor up 3 flights of stairs to my place dosen't sound too appealing... maybe i could winch it up from the window? think the manager would notice?


right now the mechanic suggests swapping the 89 head on the the 91 block, as well as the 89 oil pan (something about the pickup being better in the 89), and reuse the 91 carbs. try and run the cams the way they are and see how it goes...
 
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