STD Series (Stage-4)

STD Series (Stage-4)

The Stage-4 is the package Datsun Spirit recommends for superior street as well as race track performance. Only at this level do you begin to really see the full benefit of the DSI engine components and our god hands. The Stage-4 is the DSI standard (hence the old name, STD series), which is far from your traditional standard anything.
The Stage-4 engine comes with the Silver engine plaque, along with a Certificate of Authenticity.

True Natural Aspirated Performance Standard for the L-engine.

Stage-4 engine is equipped with our signature Stage-4 head, which has significantly larger ports, re-shaped combustion chambers to optimize the combustion, race valve guides & DSI big valves, and equipped with the DSI proprietary grind Stage-4 cam, which has drastically higher lifts yet extremely smooth torque curve from the low to high RPM range. The acceleration of the Stage-4 engine is Explosive ans silky smooth…the way a true high performance natural aspirated engine should be. The best part is, we assembled this for street in mind…this is not a pure race engine. While its output is quite significant, it is extremely smooth from the low RPM to high RPM, so you can win races with it, cruise on a highway, drive in town, or the possibilities are endless.

The Stage-4 engine is not only explosive but also extremely fuel efficient…after all, a performance engine is basically a super efficient engine, and we get 26-31mpg on highway, while easily exceeding 100hp per liter at the rear wheels.

Base engine:​​ L28 (N42 head + L28 block)
Bore X Stroke:​​ 89mm (or similar) bore x 79mm stroke 3.0 liter setup. (83mm (3.1L) possible) Special cylinder block modification
Pistons:​​​ DSI ultra light weight pistons
Rods:​​​ DSI H-beam rods
Sprocket: Adjustable Cam Sprocket
Crankshaft:​​ L28 crankshaft modified
Cam: DSI proprietary grind Stage-4 cam:
Valve train:​​ DSI Big Valves, DSI valve guides, DSI Stage-4 series valve springs & Retainers, DSI equal chip height Special Rocker Arms
Gasket: DSI Big Port manifold gasket
Head Gasket: Multi Layered Metal Head Gasket Compression:​​ 11.5 or above
HP:​​​ Approximate 300hp or more at the rear wheels, that means roughly 400hp at the flywheel.


Base Price: $12875. (Some upgrade options available.)

Note 1: The Stage-4 engine is best setup with our 50mm ITB setup. Mikuni, OER, carburetors acceptable. Weber DCO may work. We will not allow Weber DCOE. Stage-4 can NOT be run with SU carbs.
Note 2: Customer interested in the Stage-4 will be required to send us a core N42 head (it has to be usable), as we have very limited supply of N42 heads.
Note 3: If customer provides LD28 crankshaft or billet crankshaft, we may be able to use it. We do not have LD28 crankshaft to sell, and we are in the process of making our billet crankshaft (not yet ready as of Spring 2018).

FAQ, Engine Cores, and Horsepower
Please see our Frequently Asked Questions for answers to common questions about our motors and additional modifications necessary for your new DSI motor. Additionally, please read about sending and obtaining Engine Cores, and our Note on Horsepower for why our stated horsepower figures are guidelines, not quotes.