Aluminum crank pulleys have been a popular upgrade for tuners for ages. Today, there is still a lot of hay made about the detrimental effects of billet crank pulleys on Honda engines because of removing a mystical item called a “harmonic balancer.” Heeltoe’s contention is that while harmonic dampers and balancers are important on many engines, Honda engines by-and-large aren’t equipped with them. Run your billet crank pulley with confidence and enjoy the revs! First we do a quick weigh-in on various pulley brands, specifically for the K20 application (citing the TSX K24A2 in the video). It was surprising to see just how light these pulleys are!
Saving weight off the crank really helps the engine rev and sending more power to the wheels. The benefit is faster acceleration and better response. Some of these pulleys are smaller than stock, called “underdrive” pulleys, which have even less mass and spin the engine accessories (power steering, alternator, and A/C compressor) more slowly. This reduces parasitic drag. For the MOST power gain, get an underdriven pulley!
But there is some discussion online about these pulleys harming the engine.¬†This video also includes a general info lecture on exactly what the suspected issues are and why we don’t really subscribe to the doomsday-sayers.
It¬†is a highly debatable issue (even though many find their viewpoints to be strictly undebatable). The fact is, we’ve never seen actual evidence to support claims of engine damage that weren’t muddied with all kinds of other variables. We’re still waiting for the missing link in the “I installed a pulley” and “I had an engine problem” tale…so for that reason, we aren’t subscribing to the idea.¬†
Thank you for coming to The Super D-Series Comparo. If you are like me, you like the underdog. The D-series engine has become a sort of underdog in the Honda performance engine scene. Largely due to the installation of bigger and more powerful B-series power plants like the B16A, GS-R, and Type-R variants, the D-series engines usually get dumped in the trash. I look forward to the day when B-series parts get disregarded in this way in favor or the K-series’ popularity. But for now, the D-series is the budget bruiser out there!
I decided to catch some of these bits on the way to the trash and do a moderate street buildup on the stock D15 in my 95 CX hatchback. The first question that arose in my mind was, “What pistons should I use?” Being a Hardin Honda employee, I took it upon myself to order one of every D-series piston new from the factory for the purposes of documenting them both photographically and dimensionally.
The different pistons are called out by the center 3 digits in their part numbers. These are the numbers Honda uses to classify which engine the part goes in when determining part numbers. The second set of 3 digits I include give information as to what market the parts are from, and super-cession level. An A00 is a North American part while a 000 would be a World Market part. Likewise, a 010 might be a part superseding a 000.
Compression height was calculated by measuring the distance from the TOP of the wrist pin hole to the TOP of the piston (not including any dome or dish) then adding half the wrist pin diameter. Further details regarding measurements will be at the bottom of the page. Without further ado, here are the pistons:
P03-010/PM3 (I am assuming P03 and PM3 are the same since a PM3 came in a P03 box) 88-91 DX/LX, 92-95 CX/DX D15B2/D15B7/D15B8 total height: 61.76mm compression height: 30.70mm flat top
¬†PMS-A00 01-03 GX D17A.. total height: 47.42mm compression height: 27.00mm 1.50mm dome
Here are a few things I found while measuring:
Bore diameter was the same for all pistons : 74.5 mm (I tested std bore pistons)
Wristpin diameter was the same for all pistons at 19 mm except the PDN which has a wristpin diameter of 21 mm.
All wristpins were the same length at 56 mm.
Well, here it is so far…I still need to get a hold of a couple more pistons, and a couple pics of the pistons above got lost, so I will need to continue where I left off here. Oh, and before you start giving me a hard time about it, I know some of my measurements are off. The Compression height was easily the hardest dimension to get right. These measurements were meant to serve comparative purposes only. Similar measurements between pistons can probably be assumed to be equal. The conditions under which I conducted the measurements were not ideal. If nothing else, you should be able to get an idea of what you can run in your buildup. Stay tuned!
A word about rods: All D-series engines of similar displacement have equal stroke lengths. Thus, the rod lengths are the same if the displacement is the same, with one exception. The VX rod is longer that the other 1.5L engines, approximately the same as the D16 engines. The D17 engines would have longer rods still, about 3mm longer than a D16 rod.
Here is a list of what I know so far:
88-95 DX/LX/CX all use a PM3 rod (134mm)
88-00 D16 motors use the same length rods, PM6 (137mm). The D16Z6 uses a PG6 rod and the D16Y5 (HX) uses a PE1, but they both superseded to PM6 rods. The only two rods that do not supersede from a PM6 is the P2P (D16Y8) and the PDN (GX motor).
The VX rod is comparable to a 1.6L rod in length. The number for the VX rod is P07.
D17A rods are 137mm. Compression height is lower than 1.6 pistons ~3mm, deck height is similar from D16 to D17, and bore is equal. The D17A gets it’s displacement from stroke.
1.7L rods are the same from DX to EX (PLM). They are the same 137mm length as the D16 rods, share the same 19mm wrist pin diameter, have the same 45mm rod journal diameter, but have a 19.8mm wide big end, unlike the D16 BE width of 22.6mm. The GX rod has a different number (PMS) but I believe it to be the same length as the PLM.
For fun: Some pot-smokers that were making fun of me taking all these pics and measurements.