SR20 Strip Down - Part 1
Tuesday, 13 October 2009 | Comments (0) | Categories: Engine, Driveline
After the engine was taken out, I had a chance to talk over the plan with Marc, Josh and Boney from C-Red. We knew we'd be removing the head and doing all the stuff around that - alleviating any problems with the valve seats being too far gone. But that left the question on whether or not to freshen up the bottom end while it was out doing rings and bearings. That lead on to the question about the pistons. During tuning, Sean at Allstar had mentioned the engine getting a little 'noisy' up high...possibly a function of the pistons being standard Z32 pistons. The consensus from all was that it would be prudent while the opportunity was there to go with a set of forged pistons. These would then match with the Eagle conrods already in the engine with the Nissan bearings being replaced with ACL Race bearings to top it all off. So the strip down begun...
Firstly the cam cover was removed and all the camshafts were removed to allow access to the head studs.
- Specifications on the GReddy Pro Exhaust cam - 264deg 11.5mm lift
- Adjustable Cam Gears - unknown manufacturer (more than likely from Japan)
- GReddy Cams out with Tomei Rocker stoppers in the box
- GReddy branding on front camshafts
- IN and EX label on GReddy cams
- Close-up of specifications and serial number on GReddy Pro Cams
- SR20 Rockers and Cam caps all lined up - all seem to be in good condition
- SR20 Adjustable cam gears front
- SR20 Adjustable cam gears back
- Spark plugs looking pretty good
Now the reason for choosing the head in the first place was the porting and knife-edging that had already taken place on the head. In hindsight (which is a wonderful thing), I should have looked more closely at the head for the valve seat condition and depth.
- SR20 Head porting on cylinder intake 1
- And then well matched across all cylinder intakes
Now that the head was off, it was time to see how the pistons and bores had fared. These pistons came originally from the engine that came off of the shelf for SILLBEER - it didn't have an engine in the hole when I started. We eventually figured out they were from a Z32 VG30DETT engine and were fitted to this engine when it was rebuilt in Japan. We decided to stick with them originally because I was running short of cash, again in hindsight I should have just waited until I had some more fold but...meh.
Note the numbers on the top of the piston for reference are '2 EMO' followed by '45V' and '04'.
- Cylinder number 2
- Cylinder number 3
Just a slight amount of carbon built up.
Next item was to remove the gearbox and confirm the breakage that occurred at the track. Looking at the inside of the bell housing, the clutch fork was loose, and no longer attached to the release pivot. The snapped release pivot was indeed the failure - seen above as the nut looking thing to the lower left of the input shaft.
- Release Pivot Ball snapped off inside clutch fork
- OS Giken STR Twin plate clutch
- Broken SR20 Release Pivot
And that was pretty much the day. Here's a few shots of where I got to after about 3hrs or so.
- SR20 stripped intake side
- SR20 stripped exhaust side
- SR20 front with oil pump still fitted
- SR20 sump removed showing crank girdle
Next week I'll finish off the rest of the tear down removing crank, rods and pistions, oil pump and anything else left over.