Cylinders with piston set, Flat top 90x66mm. Porsche 914  ›  VW9000T4F

Cylinders With Piston Set, Flat Top 90x66mm.

The OE Match Cylinders With Piston Set is a complete replacement piston-and-cylinder kit designed for Porsche 914 models using the 1700cc Type 4 engine and 66mm-stroke crankshaft.

Featuring 90mm cast-iron cylinders and flat-top hypereutectic aluminium-alloy pistons, the kit provides the major reciprocating and cylinder components required to restore worn or damaged 1.7-litre Type 4 engine assemblies.

The flat-top piston design is intended for lower-compression engine builds, while the 42mm compression height provides the correct piston geometry for compatible 66mm-stroke applications.

Supplied as a matched set of four cylinders and pistons, together with piston pins and piston rings, the kit is well suited to complete engine rebuilds, restoration projects and repairs where the original cylinders or pistons have suffered excessive wear.

Fits:

• Porsche 914, Type 4

Engine size: 1700cc
Stroke: For 66mm stroke crankshafts
Pistons: Hypereutectic aluminium alloy
Compression Height: 42mm

Set includes: 4 pistons, 4 cylinders, 4 pins and a set of rings.

What This Product Does:

The piston and cylinder assembly forms the heart of the engine's combustion process.

During operation, each piston moves up and down inside its cylinder as combustion pressure acts on the piston crown. This converts the energy released by burning the air/fuel mixture into mechanical movement through the connecting rods and crankshaft.

The set is designed to:

• Restore worn 90mm cylinders.
• Replace damaged or excessively worn pistons.
• Restore correct piston-to-cylinder clearances when properly installed.
• Help restore engine compression.
• Provide effective sealing through new piston rings.
• Reduce excessive combustion-gas blow-by.
• Help reduce oil consumption caused by worn cylinders or rings.
• Restore more consistent combustion between cylinders.
• Support reliable power production.
• Provide the correct geometry for a 66mm-stroke 1700cc Type 4 engine.
• Provide a matched four-cylinder replacement solution during an engine rebuild.

Symptoms Of Wear Or Failure:
Possible signs of piston, ring or cylinder wear include:

• Low engine compression.
• Uneven compression between cylinders.
• Poor leak-down test results.
• Reduced engine power.
• Sluggish acceleration.
• Difficult starting.
• Excessive oil consumption.
• Blue smoke from the exhaust.
• Combustion gases entering the crankcase.
• Excessive crankcase blow-by.
• Oil contamination around the breather system.
• Increased engine fumes.
• Piston slap or knocking noises.
• Reduced combustion efficiency.
• Fouled spark plugs.
• Excessive carbon deposits.
• Poor idle quality.
• Loss of performance as the engine warms.
• Cylinder scoring identified during dismantling.
• Excessive piston-to-cylinder clearance.
• Broken or damaged piston rings.
• Cracked piston ring lands.
• Damaged piston skirts or crowns.

These symptoms can also result from valve, cylinder-head or other internal engine problems, so compression and leak-down testing should form part of diagnosis before dismantling.

Why Replacement Matters:
The piston, rings and cylinder must work together to create an effective seal inside each combustion chamber.

As these components wear, combustion pressure can escape past the piston rings and into the crankcase rather than acting efficiently on the piston.

Replacing worn components helps restore:

• Cylinder sealing.
• Compression.
• Engine power.
• Throttle response.
• Oil control.
• More consistent combustion.
• Reduced blow-by.
• Reduced oil burning.
• Reliable long-term engine operation.

For an engine rebuild, replacing pistons and cylinders as a complete matched set also helps avoid mixing heavily worn components with new parts.