Engine now in - Datsun Spririt SCR Stage III 3.0 3 L28 Engine | The Z Club of Great Britain
  1. The Z Club relies on the support of it's paid members - join the club or renew your membership here.

Engine now in - Datsun Spririt SCR Stage III 3.0 3 L28 Engine

Discussion in 'Rebuilds and restorations' started by zedhed, Mar 20, 2015.

  1. zedhed

    zedhed New Forum User

    Hi Guys said I'd report back on progress with my Datsun Spirit engine installation at Z Farm

    well it's taken a while, but the engine & re-worked suspension is now installed, and Z Farm tell me they'll have it on the rolling road shortly for a basic pre-run in setup...

    I've uploaded some pics from Z Farm, and from Datsun Spirit showing the build process (images may take time to be approved)

    Here's the Engine specs from the Datsun Spirit Manual:

    Overall Spec
    L28 (N42) block + N42 Cylinder Head base
    89mm (bore) x 79mm (stroke) = 2949cc (commonly known as a 3liter setup)
    Combustion Chamber Volume: appx 31.5cc
    Head gasket: Kameari Engine Works, Multi-Layered Metal Head Gasket (90.5mm x 1.2)
    Piston above deck: 0.315mm
    Piston volume: 5.2cc
    Compression ratio: 11.8 : 1
    Main cap Bolts Tightening Torque: 85N/m (High Strength Cap bolts)
    Conn-rod Bolts Tightening Torque: 68N/m (3/8 ARP2000 Bolts)
    Head Bolts Tightening Torque: 85N/m (Nissan Turbo bolts)
    Main cap Bearings: STD
    Connecting rod Bearings: STD

    Camshaft & Valve Timing
    Camshaft: Stage III
    Duration 290
    Max Valve lift: .495 (12.6mm)
    Lobe Center: 106 (IN: 104)
    Valve Timing @ 0.50” lift: IN: 18 BTDC, 46 ABDT, EX: 14 ATDC, 50 BBDC
    Valve Clearance: IN: 0.08” EX: 0.08” (Cold)
    Lash pads: IN: 7.0mm) EX: 7.0mm (Cam towers shimmed by 1.5mm)

    Bottom End
    Block: N42 Block, 89mm bore
    Crankshaft: L28 crankshaft, straightened to within 2/100mm. STD undersize, journals polished
    Rods: Datsun Spirit, 139.5mm H-beam rods
    Pistons: Datsun Spirit, 89x29mm pistons.
    Headgasket: Multi-layered metal head gasket 90.5mm bore, 1.65mm thick
    Oil pump: Rebuild, and modified to higher pressure setup. It is important to select proper oil with high ZDDP content.

    Will let you know how it goes...
  2. SeanDezart

    Z Club Member
    Official Trader

    11.8:1 ? :eek::smash:
  3. zedhed

    zedhed New Forum User

    according to the spec, yes. Quite high
  4. zedhed

    zedhed New Forum User

    Here's the Datsun Spirit STR Stage 3 page
    I had a few extra tweaks done, such as balancing inside and out, including pulley & flywheel, rocker arms, cam sprocket and a few other bits and bobs
  5. jonbills

    Z Club Member

    Very nice.
    Mine should be coming together in a few weeks.
    I'm aiming for a CR of about 10.5:1 with carbs.
    I make your CR 12.6:1 !!!
    You must be going with throttle bodies & EFI?
  6. SeanDezart

    Z Club Member
    Official Trader

    Balancing 'inside and out'* - you mean that's not part of the standard package ?:confused:
    *'out' meaning what please ?
  7. zNathan

    Z Club Member

    Really interested in the results of this, their engine builds look very nice on their webpage.
  8. jonbills

    Z Club Member

    I'd think pulley & flywheel & clutch cover are 'out'
  9. Rob Gaskin

    Rob Gaskin Membership Secretary Staff Member Committee Member

    Good news on the progress side.

    The CR is seriously high, if it's on carbs it'll probably run-on when the ignition is switched off.
  10. zedhed

    zedhed New Forum User

    that's right John outside important too, on the inside everything has been micro balanced

    compression according to specs I've been given is 11.8 : 1

    it's a 3.1 L I guess according to volume per cylinder

    I've also got a spreadsheet somewhere with more data which I'll upload
  11. SeanDezart

    Z Club Member
    Official Trader

    A balanced clutch ? Why does Eiji supply clutch-wise ?
  12. SKiddell

    SKiddell Having a bad day

    Why ??
    With the right squish in the cylinder head and good fuel 12:1 is easy
    Static compression is only really a guide number, the real "tell" is the dynamic compression that the cam delivers

    Mine runs in excess of 12:1 on 97 octane (dynamic is around 8:1 calculated)

    Some questions, what valve sizes were used, do you have any pictures of the cylinder head chamber work, why not go the whole hog and used a stroked crank (83mm) to get the full benefits.The cam is a fairly mild grind considering the rest of the setup, was that to get a good natured road car rather than an all out screamer?
    I would be interested in your induction and exhaust setup as primary, secondary and inlet tract length will have huge bearing on the results also what damper are you using, would hate to see all that work end up with a broken crank.
    Tell Duncan to consider an airbox, open trumpets sound great but will be subject to dust and heat induction potentially damaging the engine and killing power (reflected pulses and hot air)

    Finally youve 12.45 seconds on the 1/4 mile to beat........looking forward to see it run in anger (hope its not just going to go to Tescos and back)
    Last edited by a moderator: Mar 21, 2015
  13. zedhed

    zedhed New Forum User

    LOL well I'd prefer to have a blast on my way to that tescos-purgatory any time :)

    I doubt I'll get the best out of it until final tune-up after run-in.

    I'm not sure whether the clutch has actually, but the pulley and flywheel have been dynamically balanced along with all the usual internal components.

    I'm no expert - I just wanted an off-the-shelf reasonably powerful engine from an engine builder with legendary rep and I've always had modded classics, but as I understand it, the valve train has been "upgraded" whatever that means, and the rods, H beams / pistons are special ones made by Datsun Spirit, and have a different geometry from standard, which affects the stroke ratio, etc. Apparently this high compression geometry/piston setup complements the cam profile. As for the stage III cam, I think Eiji felt that was more than enough because of my requirements. I've owned cars with cams which develop power at high revs, and they're nice if you're driving at constant high speed but not so fun on B roads and suchlike, so I asked for an engine which is reliable and builds revs quickly, sharp and responsive (seeing it's an import using special components and so-on) and more about torque and mid range power. I decided to get it balanced because I know how important that is from a wear perspective. It was explained to me by Eiji of Datsun Spirit that when things are moving fast they should be as light as possible, and I can see how the different pivot points affect the stroke and pressures developed. I do engineering of a very different kind to this (Telescopes and suchlike) so most of it made sense, though I've got a lot to learn.

    Here's a picture of the piston setup from their website showing weights compared to stock:



    As for induction, I think I'll cover up with socks for run-in, but air box for final tuning sounds good. Do you have any suggestions I could look into, minimum installation time/effort?

    I'm pretty pushed for time (we've one year old baby, so you know how that goes...)

  14. zedhed

    zedhed New Forum User

    By the way, they sell these parts separately too and they list the specs for stuff like valves H beam connecting rods pistons, etc. you can check it out here - Datsun Spirit Engine Parts.
  15. SKiddell

    SKiddell Having a bad day

    Ive spoken to Eiji on a number of occasions (emails) and found him very knowledgable, many of his componants seem to be from Kameari (so nothing bad there)
    Hes very well known and I think that your descision to buy a complete unit from him is wise as it WILL be a package that works with some nice tweaks

    The concept of light rotating mass is very sound and one that I have employed on my engine, I use a super light A section rod (Carillo) with a custom "slipper" piston, the crank is an 83mm custom billet one from Farndon which took over a kilo off the mass

    As for a crank damper, make sure you get a good quality one (not the original Nissan unit) as crank harmonics are very prominant at certain revs and will kill an engine if not managed, Sean Dezart on here sells a very good fluid damper for good money (an ATI one can cost 500 quid)

    As for an airbox, the reason I suggest it is that I did alot of work to develop one (many rolling road sessions)but I dont sell one........MJP does and I can recommend it, but its not a quick fit, (few good things are) if your going to do it, get Duncan to fit t now. Using "socks" is very old school and is an elastaplast as open trumpets suffer badly from reflected pulses of the inner body work and WILL lose you power and creat flat spots ........I have many many dyno sheets to prove it and a rolling road bill tht would make you cry, I use adjustable length trumpets inside and airbox so I can tune the inlet tract length.
  16. Rob Gaskin

    Rob Gaskin Membership Secretary Staff Member Committee Member

    Just going from personal experiences (as usual). My old car and my DJ car (10.5:1) run-on when hot i.e. 'dieseling'


    I know the above suggests that it's a hot-spot that's causing it but I've only ever had this on high compression carb engines. Obviously FI engines cut off the fuel but as long as a carb engine is running it'll keep drawing a small amount (idle) fuel.

    I have had to stop both engines by stalling them (I did yesterday).

    If you can tell me how to prevent this I'm interested.
  17. zedhed

    zedhed New Forum User

    Hi there,

    Is a harmonic balancer essential if the pulley has already been balanced as a unit, and what kind of revs would this become an issue?

    also wouldn't the installation of balancer require re-balancing of any other components, or is that a simple bolt-on affair?

    I'll get in touch with Mike, If you have any detailed pictures of how these things are installed I would be greatful!
  18. zedhed

    zedhed New Forum User

    I should explain the harmonic balancer I have isn't fluid filled it's got some kind of polymer fill - I can't actually remember what model but it's something like this here so I'm not sure if that will suffice or I need something more expensive. Remember this is a fun car not a drag racer, well at the moment :)
  19. SeanDezart

    Z Club Member
    Official Trader

    Thanks Steve. And the airbox works too.:thumbs:

    Not essential......like certains types of insurance in ones' life but grateful to have it on the 1x occasion that it's needed. The bitch is you'll never know it saved your engines' life...it's only the breakages that're recorded :(.

    THAT'S the beauty of a fluid damper, it adjusts itself to the engine fitted upon.
  20. strugrat

    Z Club Member

    Really really interested in how this turns out and what power figures you achieve.

    I spoke to Eiji in some depth last year and he seemed a nice guy and, very knowledgeable as already mentioned and excellent prices I thought.

    He mentioned he was also speaking with someone else in the UK.

    I am still considering Datsun Spirit but I found it hard that the engine wouldn't be run on a dyno before delivery to me, so will probably be going a different way (but hopefully just as nice).

    Best of luck and keep us posted!:)

Share This Page