Nissan SR20DET Forged Engine Build (part 1)

A regular who is client running a very nice S14 200SX has decided that it’s time for a Nissan SR20DET forged engine build, firstly to freshen up a tired engine and secondly to meet his objectives of 400hp at the hubs!

The SR20 engine is so called because “SR” is the basic engine designation, “20” is the 2.0-litre displacement, “D” is for dual overhead camshafts, and “T” is for turbocharged. The 16 valve variable intake cam timing engine with Garrett T28 turbocharger responds very well to correct tuning methods.

We’ve removed the engine and transmission in order to strip the engine down for inspection and rebuild.

Nissan SR20DET forged Engine Build

 

The engine gets wheeled through to the strip down area where the “dirty work” takes place.

 

The engine comes apart piece by piece for inspection.

 

Removing the oil sump reveals evidence of the engines age!

 

We had previously installed HKS high-performance camshafts which are still in good condition.

 

Here’s the cylinder block components following the stip down.

 

The HKS camshafts are removed from the cylinder head and are still in great shape, albeit quite dirty.

 

The original pistons, connecting rods and oil squirter jets are shown here. They’re not in too bad condition considering the mileage and the use.

 

The cylinder head prior to removing the valves, springs and followers.

 

The SR20DET cylinder block is constrained by the strength of its cylinder walls, and it’s not unusual for them to crack at high cylinder pressures so the remedy for this is to install HKS high-performance cylinder liners or Toda Racing high-performance cylinder liners

 

The cylinder block has to be machined to accept the HKS or Toda Racing cylinder liners, then bored and honed to suit the pistons. Here, the block is completed and ready for use in this high power application. The Nissan SR20DET forged engine build is coming along nicely!

 

We always measure each finished bore for size, ovality and taper to ensure that each cylinder has the correct clearance. Also, specifications and tolerances are recorded to ISO9001 standards.

 

The original crankshaft has been measured for wear, ovality and taper, and has been crack tested and micro-polished.

 

The standard Nissan pistons are quite weak and tend to fail in the ring land area when subjected to increased cylinder pressures. It’s always a good idea to uprate the pistons to heavy-duty forgings, and we tend to prefer high-quality brands such as HKS, Toda Racing or Wossner which will provide reliable performance with low noise level and low oil consumption.

 

The standadrd connecting rods are not robust enough to withstand the objectives so we use forged steel H section rods with ARP high tensile bolts from Cosworth, HKS or Toda Racing.

 

During an engine rebuild we normally have many of the components plated to get them looking like new again.

 

Heavy duty high tensile Cosworth head studs and Cosworth metal head gasket are used to withstand the higher cylinder pressures that the standard Nissan components are unable to cope with.

 

The pistons and rods are assembled and installed into the cylinder block.

 

Unfortunately, the valve guides were badly worn. Nissan does not offer valve guides separately (only with a new head casting), so we used Toda Racing high-performance valve guides.

 

After installation of the valve guides and machining of the valve seats, we gas flowed the intake and exhaust ports to improve the airflow efficiency which improves engine performance.

 

The valves were duly lapped in with course and fine paste, the cleaned and reassembled with the HKS valve springs

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We’re using a Cosworth metal head gasket and Cosworth head stud kit.

 

We’ve fitted the ported cylinder head to the cylinder block, and are now fitting the HKS camshafts.

 

We’ve painted the valve cover the same colour as the car, which should look good.

 

The painted valve cover is now fitted to the engine.

Continuation of this Nissan SR20DET forged engine Build thread can be seen here