Follow along as I build a high performance 914 engine
- Begin tear down
- Long-block to short-block
- Split the case
- Take apart the crank assembly
- Remove the oil pressure relief valve
- Clean up the fan shroud
- Remove secondary oil relief valve
- Replace oil galley plugs
- Clean case halves
- Machine oil pressure sending unit mount
- Measure piston ring gaps
- Dry assembly (TDC & crank end-play measurements)
- Electromotive ignition sensor mounting
- New TDC mark on fan
- Case clearance for connecting rods
- Prepare the camshaft
- Crankshaft assembly and rod clearance
- Rod bearing defects
- New heads arrive!
- Rebuild the alternator for $8
- Modify engine tin
- Setting up to measure valve geometry
- Installing rocker studs
- Measuring pushrod length and valve travel
- Evaluate valve-piston clearance
- Making custom pushrods
- Lapping cylinders to heads
- Modifying windage tray
- Final crank assembly
- Short-block assembly
- Installing pistons in cylinders
- Long-block assembly
- Installing sheet metal
- Distributor drive cover & CHT sensors
- Installing exhaust manifolds
- Modifying Bursch muffler
- Installing transmission
- Rebuilding carburetors
- Fitting velocity stacks
- Building cable throttle linkage
- Making oil pressure
- First start & initial tune
- Preparing for engine installation
- Engine installation
- CHT gauge
- Throttle linkage
- First drive
- On the dyno
Installing Pistons in Cylinders
The first step I did in preparing the pistons was to put in the first wrist pin retaining clip. There are 2 of these - the first one you can put on before you put the piston into the cylinder, and the other one goes on after the wrist pin is installed (the wrist pin is the part that holds the piston onto the connecting rod). The retaining clips that came with my pistons are spiral spring clips - they come flat, but are easier to install if to "flex" them open to look more like a spring:
To install them, get one end started in the groove, then push the rest in little-by-little with a screw driver:
Because of the stroke / connecting rod length / piston selection for this engine, you'll notice that the wrist pin bore goes through the oil ring grove. Obviously, because of this, the oil rings will have to be installed after the pistons are connected to the connecting rods. To help support the oil ring, there is a metal band that comes with the pistons that will act as a little "shelf" which will bridge the open space. I put this on next and pushed it up to the top of the groove - I'll have to push it back down to the bottom of the groove before the oil ring goes in place.
Now, it's time to put on the compression rings and put the pistons into the cylinders!
And, finally, the piston / cylinder assemblies are all ready to be put on the engine:
