High comp pistons, or shaved head??
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    Vtec what? BLK02XD has not yet proved knowledgeable BLK02XD's Avatar
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    Default High comp pistons, or shaved head??

    which is the better way to go to raise compression, the pistons, or the head.
    im going to be getting a spare motor this week if things work out right. so i figure ill pull the head off that and send it to the machine shop. im gonna get it ported and polished definately, wether or not i want to shave it down though is the question. does anyone know if anyone has used the tigerlilly high comp pistons, or anyone who has shaved down the head on the beta motor, and if ones better than the other?

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    Ultimate Post Whore FordFasteRR can identify a wrench FordFasteRR's Avatar
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    Default Re: High comp pistons, or shaved head??

    sorry, I have not heard of anyone doing this yet.

    However, from the books that i've read on engine tuning.. every point of compression that you increase gives you from 3-5% more power, but you need to increase the octane to keep things from blowing up.

    now, if you can raise the compression and still use pump gas, you are golden !

    you can get a nice power gain basically for free.

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    Mad Scientinst oregun has not yet proved knowledgeable oregun's Avatar
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    Default Re: High comp pistons, or shaved head??

    I talked to Dave at RPW about going high compression. If you do go this route, you want to port and polish the head, because you will get carbon build up like crazy.

    I would also advise using pistions vs. shaving the head. This method maintains the proper squish area.

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    Vtec what? BLK02XD has not yet proved knowledgeable BLK02XD's Avatar
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    Default Re: High comp pistons, or shaved head??

    ok i looked around a little bit and from what ive found they say 10.25.1 is the highest on pump gas. thats only a quarter of a point more correct?
    so not too big of a gain without going to race fuel which isnt the way i want to go.

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    Ultimate Post Whore FordFasteRR can identify a wrench FordFasteRR's Avatar
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    Default Re: High comp pistons, or shaved head??

    you dont have to use race fuel..

    you can mix in a gallon of TOLUENE from sherwin williams and raise your octane safely .

    Here is an article on this:

    http://evo.jedinite.com/toluene.html

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    Poster God faraco3 can identify a wrench
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    Default Re: High comp pistons, or shaved head??

    Dont the Betas have a compression of 10.3:1 ?

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    Default Re: High comp pistons, or shaved head??

    According to webtech its 10.1:1

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    Default Re: High comp pistons, or shaved head??

    Quote Originally Posted by oregun
    I talked to Dave at RPW about going high compression. If you do go this route, you want to port and polish the head, because you will get carbon build up like crazy.

    I would also advise using pistions vs. shaving the head. This method maintains the proper squish area.
    Are you referring to quench?

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    Senior Member O_GT has not yet proved knowledgeable O_GT's Avatar
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    Default Re: High comp pistons, or shaved head??

    Quote Originally Posted by FordFasteRR
    you don't have to use race fuel..

    you can mix in a gallon of TOLUENE from Sherwin Williams and raise your octane safely .

    Here is an article on this:

    http://evo.jedinite.com/toluene.html
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    Ultimate Post Whore FordFasteRR can identify a wrench FordFasteRR's Avatar
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    Default Re: High comp pistons, or shaved head??

    Quote Originally Posted by O_GT
    Cool stuff ford.How do you find this stuff

    lol, I spent some time on the evo forums and gained some knowledge LOL !

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    19 second madman tharptroy has not yet proved knowledgeable tharptroy's Avatar
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    Default Re: High comp pistons, or shaved head??

    squish ~ quench

    pistons will always net better results. shaving the heads is the half-assed way of doing it.

    10.25:1 is a joke.

    the car from the factory runs close to that on 87 octane.

    I dont see any reason why you cant run 12:1 if you set it up right. (daily street use)
    11.5:1 would be a little safer. you're going to have to go with custom pistons, because I havent seen any pistons with a good streetable compression ratio. its either 9:1 or 13:1

    and you're going to need head work

    they'll have to take a little off of the head to get you a nice mating surface, and I can guarantee you that you are wasting your time if you dont get cams to optimize the setup.
    Last edited by tharptroy; 12-12-2004 at 10:00 PM.
    "Setting up your car for autoX is like tuneing your car for parking." -liveforphysics

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    Super Hero XDGT03 has not yet proved knowledgeable XDGT03's Avatar
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    Default Re: High comp pistons, or shaved head??

    I'm really interested to see what he would get from just doing the porting. Particularly on the exhaust side. Carbon was supposed to get the head flow tested but he gave up I guess.

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    Vtec what? BLK02XD has not yet proved knowledgeable BLK02XD's Avatar
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    Default Re: High comp pistons, or shaved head??

    well im getting my spare motor weds morning, so im gonna see what i can do with the head off that one, either port it a little bit myself, or save a little money and give it to the machine shop to let them do their magic.

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    Ultimate Post Whore FordFasteRR can identify a wrench FordFasteRR's Avatar
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    Default Re: High comp pistons, or shaved head??

    BLK02XD, you could also get an OBX cam sprocket and further tune the ported head ...

    I suppose that if I gained 2 whp and 4 ft.lb torque on a stock head, you could easily gain double that with a ported head !!!!!!

    obviously, the stock cams are set too far back from the factory to make peek power / torque!
    Last edited by FordFasteRR; 12-14-2004 at 09:17 AM.

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    Default Re: High comp pistons, or shaved head??

    I dont think anyone has gone this route (ie high compression) I know that Rshack with cams, header, exhaust, and intake (not sure about pulley) is making 165whp. Ford you said that for every point of compression you increase you should see a gain between 3-5%, coupled with some good cams (268 or 272) and a head job. This may be another route for some power though I see it costing no less than FI. Oh well im sure someone will try it.

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