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Doing some stupid shit to an old datsun head

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    Meh, everything has been done before.

    Just milled it down .040" & CC'd all the chambers, get this - all within .2cc!
    I would have been happy with within .5cc & was almost expecting to have to tweak a little.

    Can't mill it to finished thickness until I get the proper valves, but looks like another .030-.035" needs to come off.

    Gotta make a bore adaptor for an 86.5mm bore to flow test & find my Datsun valve lifting jig, so figures will be late this arvo.


      PS - that Peter guy should watch his back, he doesn't exactly have a clear conscience in regards to stealing ideas.....

      Mark will be in here some time soon.


        This is now on and our Facebook Page too for a bit more exposure for you Tony.
        Turns out, far too much has been written about great men and not nearly enough about morons

        Originally posted by seedyrom
        my neighbours called the cops...... not because of the sound of me working in the garage was too loud, but because i taped a cardboard box to my back, covered my self in vaseline and pretended i was a snail on their lawn


          Originally posted by TK View Post
          Just milled it down .040" & CC'd all the chambers, get this - all within .2cc!
          Arsey prick.
          Originally posted by piss98
          I wish Kochie would get blown out to sea and never found, in fact most of those dumb cunts standing in the rain telling people not to stand in the rain need to get fucked. Stupid tart on the news last night talking to the weather guy "wow you look totally drenched there whateverthefuckhisnamewas." No shit you vapid bitch he is standing in a fucking cyclone.


            Pics of finished porting, guides back in etc, just some quick ones while it's clean:


              Epic, can't wait for dyno.


                My god, that's sexual.
                Japanese Nostalgic Car - Dedicated to classic japanese cars


                  Originally posted by Komdotkom View Post
                  I want to do one of the six cylinder heads with the cast in liners and do a D shaped exhaust port with a raised floor, but I don't have any time for another project at this point.
                  Edit: Looks like there's a four banger with the cast exhaust port liners too.
                  I raced on one of these for 10 years, Mick Marriot did the head back then and the power was amazing. Early SR20s strugggled with it. 2.3ltr tho.
                  GURU ENGINEERING PTY LTD


                    Meh, no Les Collins no care

                    I can't get over how round you get the ports by hand, fucking top work!


                      Just flowed it, needs a bit more of a rub

                      Pretty much hit my flow targets, but I've got some turbulence/flow separation issues at high lift, above .600" lift the flow detatches from the short turn & it backs up 10cfm, I like a head to flow clean at least .100" past peak valve lift.
                      I poked around a bit with a velocity probe, flow balls & a small steel ruler to work out where the issue is - looks like I need to blow out the bore side wall over the short turn a little, with the ruler I was able to get flow stable at .650" lift by pushing air across to the bore wall side & unloading the bore centre side - flow jumped up past 240cfm.
                      Guides are in now & I don't have to pull them to rework that area so I should be able to nail it down pretty quick.

                      Also have to 1/2 shaft the TB's - with the intake on flow dropped a solid 10-12cfm, not good enough.
                      Throttle shafts are fairly thick, so I'm gonna pull em out & cut the screw head side off, then run the screws straight on the butterflys, that should be enough to get it where it need to be.

                      On the exhaust side as suspected I fell a little short, not tragic tho & the flow is nice & stable, I'll leave it be - I'm having the cam ground with not-so-great exhaust ports in mind & I've got the cross section etc I need.
                      Alcohol fuels blow down faster than petrol type fuels due to burning slower, so you don't actually need an 'ideal' exhaust port - handy when you're talking L series heads!

                      If you're familiar with L series flow figures you'll note the low lift numbers are down over what you'd usually see - that's the chamber doing that, despite the cost to low lift flow it'll make more power - you can't always trust a flow bench, some things they'll tell you would lead you in exactly the wrong direction if you listen!

                      Anyway, flow figures as it is now:

                      .1 - 58
                      .2 - 104
                      .3 - 147
                      .4 - 180
                      .5 - 217
                      .55 - 229
                      .6 - 235
                      .65 - 226 - turbulent

                      .1 - 54
                      .2 - 89
                      .3 - 123
                      .4 - 138
                      .5 - 146
                      .55 - 149
                      .6 - 151
                      .65 - 153
                      .7 - 155
                      .75 - 156
                      .8 - 157


                        How is my Head going?


                          Packed, will book freight in the morning.


                            Retracted - was a little bit harsher than it needed to be. All i see from DUDS is sooky cunts, and people sucking the admins dicks.

                            Will be interesting to see what this does. I have a mate doing a L series rally car and this is interesting to see what a 40 year old design is capable of.


                              ^^ Have you met him? He can get overly excited/opinionated about things at times but to me that is something that is refreshing to see. *my opinion may be a bit biased as he did build an engine for me *

                              BTW, great work TK, can't believe the detail and finish all achieved by hand.


                                Wait till you work out that angle milling the face to blck can stand valves up a bit more vertical to pistons, ala U20 Nissan heads.
                                Still heed to open up head bolt holes and mill the flats for u/sdes of head bolts/studs etc.
                                if you get this far after reading the above, good on you!
                                If i make spelling mistakes, syntax errors, or just mss letters in words, it is because i am lw vision/vision impaired.
                                Dont drive or race no more. Bit of a cunt of a thing.
                                I cant see what keys my fingers hit when i type.
                                Its called Cone and Rod Dystrophy, un fixable, i get worse, its a hereditary cunt f a thing.