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Doing some stupid shit to an old datsun head

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  • Xnke
    replied
    You'll get a kick out of this one...





    As soon as I can work out how best to move the intake valve, that method will get a re-visit. I was able to fit a 46mm valve in without moving it or the head, but haven't done it yet. Been working on the Frankenford more than anything else.

    EDIT: Those photos are from a HybridZ member; I've done similar but not CNC like that one. He's running a 46mm valve in that and IIRC was able to touch 230CFM at 0.550" lift on the intakes, I do not know what he achieved on the exhausts.

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  • TK
    replied
    PS - great (or maybe not) minds think alike, those chambers look very familiar!

    & just to clear it up for others reading along - I had no idea anyone had reworked chamber like this before I did it, I'm not really in the Datto community & have NFI what others get up to other than talking with Mark the last few days.

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  • fly510
    replied
    Originally posted by clutch-monkey View Post
    Lol just read the Datsun fb page this morning, fuck the Datsun community is a toxic shit pile
    as a long term Dato owner/tinker and early adopter of Dud's this statement is a massive and uneducated generalisation. Like with any make & model of car there is always differing opinions and sometimes the discussions get out of hand.

    There is plenty of posters in the DUD thread I cannot stand, either on the interweb or in person, but for the most part dato owners are pretty down to earth, reasonable and practical human beings.

    If I'm to pick on one group of Datsun owners its the Z guys. Mostly tossers and old wind bags.

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  • TK
    replied
    We're stuck with the TB's we have for now - budget constraints, time constraints etc.
    This really has to be on the dyno end of next week!

    But I've talked with the owner about leaning on this setup quite a bit harder down the track if this current setup works out pretty good.
    I'm thinking an L18 crank, 89mm bore & longer rods for a 1.93L engine (2L capacity limit), that extra 3mm of bore will do wonders for valve shrouding - would be worth a pretty easy 15hp or so methinks.

    Owner is a dedicated L series nut, this is actually one of Peter Hall's old motors (he knew Peter well) - the plan was to switch over to an SR20VE down the track, purely to be competitive, but if the results of just a head swap & fuel change are promising enough then we may get to persist with the L.

    More time being available down the track would see ex port tounges bolted in, a swap in intake setup ( Maybe one of yours, maybe a single TB on a plenum & runners free of throttle blades - dunno) & I'd like to track down a bigger cam - into the early 270's duration, or maybe even look at the roller setups.

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  • munyard
    replied
    Originally posted by clutch-monkey View Post
    Lol just read the Datsun fb page this morning, fuck the Datsun community is a toxic shit pile
    -Thats a bit harsh, some of my best friends own datsuns. - i dont do facebook, although im tempted to agree with you after the 'wheel nut incident'

    Since speaking the other Day Tony, thats now 4 dudes who have told me i should check this out, and its been a great read.
    Ive never really been a fan of the secret squirrels, its was well out of hand at all the little race motor shops in the UK. Years back i had to try explain to folks like some mad crackpot why you would really want to move the valves on these engines (relative to the bore).

    People seem to be catching on that L-series valves have been put over 3mm off the centreline of the bore and with a 12deg valve angle, the more valve lift, the further into the bore it goes..

    The really experimental L-Head work used to be all about raising the inlet port sometimes miles, with myself, Les collins/peter mac (independently at that point) boring for a tube straight down from the base of the rocker cover to the inlet valve and we later found out, getting about the same sort of flow numbers from a 44 to 46mm valve, the hint was right there -they didn't really improve and i knew that we should be running way more than even a 46mm inlet valve, why is it literally hitting the bore instead of being better centered for flow?
    So being younger then and asking too many people that question and cutting up lots of heads i soon had some experimental heads with massively moved valves (finding it does little for the exhaust, they need tongues for the sharp short turn ) with nearly 48mm inlet valve's flowing more than 60hp over anything we had seen and some 'safer' versions finding their way into PRC rally cars (the rules required this head) that made 4wd turbos look silly.

    It was prolly around 05 when we first had 121rwkw from this machine https://www.youtube.com/watch?v=YpZkfF9i68c it was 2L, within the rules and on pump fuel and carbies, and although folks will claim say double that now on the internets, not many people believed it at the time and with continuing results it was enough to turn from a shit idea into a good one and apparently make folks want to cut a head up and put it on the wall, and copy it. (enter shitfight here) or pm me if you like cos im keen to know about that stuff as i dont seem to have been kept in the loop..

    So its pure gold what im seeing here TK and id rather hear about it and see results and i so much like how similar the chanber shape is to this early moved valve methanol one, notice also the different method of moving the valves 3 or 4mm to achieve a very similar outcome to yourself, its not been finished or sanded but shape wise im sure folks can see the similarities in the compact chanber and central plug, and theres zero copying here, more like a very similar understanding of what is needed.

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    -also Tony, do you remember how little flow was lost last time with my 42mm Quad throttles? maaaby they would need a couple of mil overbore for this bigger port circuit motor but just like with slides or barrels ill bet even as is you would instantly get the total inlet flow you are after straight off, compared to the tortured path of the weber pattern to the simesed datto ports. -and ill get the inlet valves off to you thisarvo, be curious if they flow better and keen to see how it all goes.

    Leave a comment:


  • TK
    replied
    LOL, just had a chat with Baz, he saw all the stuff on facebook as well & called me, picking up some valves from him tonight & gotta cart the head down there as well for him to have a poke at.

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  • dave1600
    replied
    Originally posted by 260DET View Post
    Who/what is DUDS?
    Facebook group - Downunder Datsuns

    Leave a comment:


  • that_guy
    replied
    Originally posted by TK View Post
    Yeah, I thought about angle milling, but there would not be a lot to gain & you make the head thin on the plug side - can cause gasket sealing issues. I don't see it as worthwhile.

    The proof of the pudding will be on the dyno in a couple of weeks, everything else is just guesswork!

    Can't do much today, have to get some subi stuff done & gotta weld up a holden 6 turbo exhaust manifold, I've reworked 1x intake port & got part way through 1/2 shafting the throttles but have to leave it there.
    Could you take a picture of what you're doing to the throttle? I cant picture it in my head.

    Leave a comment:


  • TK
    replied
    Yeah, I thought about angle milling, but there would not be a lot to gain & you make the head thin on the plug side - can cause gasket sealing issues. I don't see it as worthwhile.

    The proof of the pudding will be on the dyno in a couple of weeks, everything else is just guesswork!

    Can't do much today, have to get some subi stuff done & gotta weld up a holden 6 turbo exhaust manifold, I've reworked 1x intake port & got part way through 1/2 shafting the throttles but have to leave it there.

    Leave a comment:


  • 260BC
    replied
    Who/what is DUDS? Have met Peter Mac, he did a shit stir on HybridZ about bullshit US power figures which was fun. Rebello in particular.

    EDIT Hi Xnke

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  • Xnke
    replied
    With as flat a valve angle as the L head has. I have to wonder how much angle milling would really gain here. Would be a lot of fucking around, for sure, almost as much as lifting the exhaust ports.

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  • Supashake
    replied
    Originally posted by marshy View Post
    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.
    40???? try closer to 50.

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  • dat2kman
    replied
    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.

    Leave a comment:


  • methodmania
    replied
    ^^ 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.

    Leave a comment:


  • marshy
    replied
    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.

    Leave a comment:

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