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  #1  
Old 20-03-2015, 03:10 PM
zedhed zedhed is offline
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Engine now in - Datsun Spririt SCR Stage III 3.0 3 L28 Engine

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...
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  #2  
Old 20-03-2015, 03:25 PM
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11.8:1 ?
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  #3  
Old 20-03-2015, 03:32 PM
zedhed zedhed is offline
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according to the spec, yes. Quite high
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Old 20-03-2015, 03:36 PM
zedhed zedhed is offline
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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
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Old 20-03-2015, 03:50 PM
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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?
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Old 20-03-2015, 04:13 PM
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SeanDezart SeanDezart is offline
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Quote:
Originally Posted by zedhed View Post
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
Balancing 'inside and out'* - you mean that's not part of the standard package ?
*'out' meaning what please ?
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Old 20-03-2015, 04:37 PM
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Really interested in the results of this, their engine builds look very nice on their webpage.
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Old 20-03-2015, 04:56 PM
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I'd think pulley & flywheel & clutch cover are 'out'
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Old 20-03-2015, 04:57 PM
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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.
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Old 20-03-2015, 10:38 PM
zedhed zedhed is offline
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Quote:
Originally Posted by jonbills View Post
I'd think pulley & flywheel & clutch cover are 'out'
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
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Old 20-03-2015, 10:40 PM
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A balanced clutch ? Why does Eiji supply clutch-wise ?
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  #12  
Old 21-03-2015, 03:05 AM
SKiddell SKiddell is offline
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Quote:
Originally Posted by Rob Gaskin View Post
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.
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)

ZedHed
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 SKiddell; 21-03-2015 at 03:40 AM..
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Old 21-03-2015, 09:00 AM
zedhed zedhed is offline
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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...)

Nick
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Old 21-03-2015, 09:04 AM
zedhed zedhed is offline
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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.
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  #15  
Old 21-03-2015, 09:50 AM
SKiddell SKiddell is offline
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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.
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