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P8R head?

Discussion in 'Engine Building' started by Sed8ed, Oct 16, 2004.

  1. Sed8ed

    Sed8ed New Member

    I have come accross a p8r head off of an aussi b20b engine... the block was used in a crvtec and I picked up the head as a spare; this head seems to have a larger quench area (measured 83mm) and larger valves than the stock ls head I have. I cant find any information on this head so does anyone here know the spec's for it?
    I was also wondering if I could run it on a stock ls block since the quench area is larger than the bore of the block
  2. MikeBergy

    MikeBergy Blah blah blah....

    I've never heard of it before, but I wouldn't run it on a stock ls block if the chamber isn't the same diameter as the cylinder bore.
  3. Sed8ed

    Sed8ed New Member

    Well after some research, I have found that this is a very rare jdm (and I guess aussi too) b20 head with an 84mm quench area and 33mm intake valves just like a vtec head. It is supposed to flow better than a ported B18a/b and a little better than a pr3 head. Now is it for certain that this cannot mount on an ls block with an 81mm bore. I would really like to know since with a minor pnp this head would flow tons better than my existing head which could then become my spare.
  4. MikeBergy

    MikeBergy Blah blah blah....

    I can't say for sure if it is possible or not, since I have never seen the head. All I know is that your compression will suck if you have an extra 1.5mm of area in the chamber relative to the cylinders. You'll also likely have problems blowing head gaskets in the event that it physically fits the block, because the gasket will either match the block, or the head, but not both. After that, you have the issue of mass turbluence inside of the chamber on the compression stroke, because of the mismatched bores and resulting lip at the head/block interface. If you have a combustion engineering background, you might be able to modify the combustion chamber a little to make that lip actually work to your advantage with a more complete combustion process, that is beyond the scope of my knowledge. The ide would get a no-go from me unless it was a research project for my own quest for knowedge. It would never make it into my car without extensive research done first.
  5. Sed8ed

    Sed8ed New Member

    Hence the reason im posting here... I didn't think the mount through properly, I know that the larger combustion chamber will lower my compression down to 10.1:1 but I didn't take into consideration the difference the lip would make plus the fact that I would have to use a P8R head gasket (84mm). My logic was that if honda were to mount the p75 on most b20's with the smaller quench area then why couldn't I mount a head with a larger quench area on a b18. I see now why that wouldn't work.

    Anyone with a b20 want a really good head for it... cheap
  6. MikeBergy

    MikeBergy Blah blah blah....

    I'm not interested in buying the head, but I'd love it if you had some pics of the combustion chambers of that head. I'd like to compare them to the one on my b18 head.
  7. phunky.buddha

    phunky.buddha Admin with a big stick Admin


    I'd like to see pictures too.
  8. johnskx125

    johnskx125 Junior Member

    i have 2 P8R's in my garage...? Do you need?
  9. johnskx125

    johnskx125 Junior Member

    with manifolds...too..
    manifolds have torque curve. strong results for b20/ls's
  10. StyleTEG

    StyleTEG Senior Member

    Are you looking to sell one of them by chance?
  11. BigC-ivic

    BigC-ivic Junior Member

    I am interested. I sent you an e-mail.

    If you don't get it, send me one

  12. BigC-ivic

    BigC-ivic Junior Member

    there's a real echo in here
  13. integraracer157

    integraracer157 Junior Member

    i have a complete pr8 head with manifold, tb fuel rail injectors etc. i will sell for 200. i bought it for the block. i can take pics if anyones want to see, its very clean.
  14. brian11to1

    brian11to1 Senior Member

  15. Scorchin Civic

    Scorchin Civic Senior Member

    Well, I know that about six months ago the head that was on my B20B went bad. I knew that for the most part the head was just like a LS head. I had a good PR4 head ( 90-93 ) in my garage so I decided to use it. I bought a new head gasket for the B20 block ( 84mm ) and slapped everything together. I have not noticed any problems since then and this is the same setup that I have ran a 14.34 in the 1/4 being all motor non-vtec. However, who all on here has a P8R head that would like to part with it and for how much.

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