Starting from the top of the engine with the cam shafts
DE inlet lift 0.388" (9.9mm) duration ~250deg
exhaust lift 0.360" (9.1mm) duration ~250deg
DET inlet lift 0.355" (9mm) duration not measured
exhaust lift 0.360" (9.1mm) duration ~250deg
The duration of the DET camshafts was hard to measure cos the engine was locked solid (by con rod through block). Measurements are in inches due to that being the scale on my dial indicator.
The exhaust cams are the same on both motors but the DE intake cam has more lift meaning more air can get into the cylinder resulting in more power so swapping in a DE intake cam is a good idea. The AFM registers more air going into the engine and the computer adds more fuel to compensate so you shouldn?t need a new ECU for this mod alone. While your in there clean the cam shaft oilers (2 tubes running along the top of the cams) as they can clog with infrequent oil changes and cause accelerated camshaft wear.
Moving down the block the pistons are obviously higher compression in the DE. The DE gudgeon pins are lighter than the DET ones but only because they are shorter and so the two are not interchangeable.
Interestingly enough the Z32 VG30DE engines have tapered gudgeon pins that fit the DET pistons and rods and save ~10g weight per cylinder. Savings in reciprocating mass give more power and a freer revving engine. This will most likely require a crankshaft balance (I?m getting one on this engine build but I also modified the crank somewhat).
The rods are the same length and general appearance but the oil squirter for cooling the undersides of the pistons is further down the DE rods (probably as less cooling is required in the DET application). There are also some oil squirters bolted to the inside of the block for further cooling of the underside of the pistons in the DET motor. Check these are there if you are buying a bare block for a DET. Although the DE and DET blocks have the same casting number (52F) the DE block has not been machined to accept these oilers (nor does it have the turbo oil and water line fittings) this means that without expensive machining a DE block cant be used on a DET. A DET block could be used on a DE if you want insane engine oiling <FONT face=Wingdings>J
The DE and DET cranks appear identical.
I?ll also list the weights of various components so you can compare and after market items without having to disassemble your engines<FONT face=Wingdings>J
DET pistons: ~390g with rings
DE pistons: ~380g
DET gudgeon pins: ~122g z32 DE pins ~112g
DE gudgeon pins: 101g
DET rods: ~640g including rod bolts but not bearing shells
DE rods: ~620g including bolts not bearings
All weights are approximate as the weight varies from rod to rod and pin to pin etc.
Another difference is the power steering pump which is much bigger on the HICAS equipped versions of the Silvia. This probably uses more power so if you convert to no HICAS consider the smaller p/steer pump.
The rocker cover is also different but only because the DE one is silver <FONT face=Wingdings>J and also doesn?t have holes drilled and tapped for screws to hold the coil packs and cover of the DET
The only other difference between the two engines is that the DE has a distributor running off the front of the exhaust cam whereas the DET has individual coil packs for each cylinder and has a crank angle sensor running off the exhaust cam. An interesting side note here is that if you have adjustable cam gears here you will need to check you ignition timing each time you adjust the exhaust cam timing as the crank angle sensor (or distributor on the DE) will be moved slightly with the camshaft.
the oil pump on the DE is the same pattern of gear pump but not as deep as on the DET which means less flow (because there is no squirters on the de)
Sumps, water pumps are the same.
The intake manifolds are also the same.