Tech Article: The Quest for more Power using the L-Series 6 Engines
by Ben Pila Jr.
Member at Large
More power, more speed. These are things that "Scotty" tries to get "Capt. Kirk" on the "Enterprise" but more importantly, these are the things that many of us early Z owners would like to have. I am now on my own quest for speed as I begin building a new engine for my own Z. With that said, this and future articles will explain how to put together an engine set-up that will:
1. Gain more power than any stock L6 can make.
2. Return gas mileage better than 20mpg (I believe 27 hwy. mpg is possible.)
3. Still pass (or squeek by,) the California emissions test for 1975-78 engines and most 79-83s.
4. Do this build-up on a low dollar budget.
The charts that I have provided in this article are courtesy of Jim Wolf Technology. Review the charts and familiarize yourself with the specifications they contain. To fully understand the charts, I will need to explain (in the next article,) what each of the different head, block, and piston numbers represent and then I can begin to expand on the combinations possible. In future articles I will explain where you can get all the parts, how much the parts and labor may cost, and what to do with the parts to finish the engine build-up. I will later explain the different induction system options using carburetors or fuel injection and turbo systems. The potential horsepower for the "big" L6 engines should fall in the 175-450 HP range. Yes, 400+ HP is possible and has been done with L6 engines but reliable street performance will be more likely fall in the 175-300 HP range. I believe there can be good reliability from a 300+ set-up (using fuel injection,) but there will be few willing to get to that level. I recommend making a copy of this and all future articles in this series and keep them all in a folder for easy reference. So follow along with this series and your quest for speed may be satisfied.
|HEAD||VOL. C.C.||INT VALV.||EX VALV.||EXH. PORT||PROD. DATES||H/GASKET||HEIGHT||DIA.||C.C.||PART #|
|E31||42.4||42||33||square||10/69 - 7/71||L28 STD||1.25||88||7.60||11044-P7911|
|E88||44.7||42||33||square||9/71 - 7/72||HKS METAL||1||91||6.50||11044-91MM1|
|N33||47.8||42||33||square||8/72 - 7/73||HKS METAL||2||91||13.01||11044-91MM2|
|N33/P50||47.8||42||35||square||8/73 - 8/74|
|N42||44.6||44||35||square||9/74 - 7/77||PISTON||DIA MM.||PIN HEIGHT||DISH C.C.||PART #|
|N47||44.6||44||35||round||8/77 - 3/78||KA24E STD.cut .5||89||33.5||0||12010-40F10|
|P81||44.6||44||35||round||2/79 - 6/80||KA24E +1.00 cut .5||90||33.5||0||12010-40F73|
|P79||53.6||44||35||round||7/80 -||Z24 STD. cut .5||89||33.5||13||12010-83W01|
|P90||53.6||44||35||square||12/80 - 7/82 TURB.||Z24 +1.00 cut .5||90||33.5||13||12010-83W03|
|P99||53.6||44||35||square||8/82 - TURB. HYD.||Z22S STD.||87||35||9.33||12010-06W11|
|PRACTICAL PISTON / ROD / CRANK COMBINATION|
|NO.||PISTON||ROD||CRANK||PIST/DECK +/-||CC VOL +/-||SIZE C.C.s||CRANK||STROKE||PART #|
|#1||KA24E STD.cut .5||L24||LD28||0.13||-0.8||3098||L28||79||12201-P3000SV|
|#2||KA24E +1.00 cut .5||L24||LD28||0.13||-0.83||3168||LD28||83||12201-V0790|
|#3||Z24 STD. cut .5||L24||LD28||0.13||-0.8||3098|
|#4||Z24 +1.00 cut .5||L24||LD28||0.13||-0.83||3168||BLOCK||HEIGHT|
|#7||KA24E STD||L24||L28||-1.37||8.5||2949||R0D||LENGTH||PART #|
|COMPRESSION RATIO USING HKS 1.MM HEAD GASKET FOR ABOVE COMBINATIONS|
Rod width at small end must be reduced to fit KA24 and Z24 pistons.
‘91+ 240SX pistons can be substituted for Z24 pistons.