Tech Article: The Quest for more Power using the L-Series 6 Engines

by Ben Pila Jr.
Member at Large

Part 1

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
							Z22S +1.00	88	35	9.33	12010-06W13
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
#5	Z22S STD.	L28	LD28	-1.02	6.06		2960		L28	207.87
#6	Z22S +1.00	L28	LD28	-1.02	6.2		3028
#7	KA24E STD	L24	L28	-1.37	8.5		2949		R0D	LENGTH	PART #
#8	KA24E +1.00	L24	L28	-1.37	8.71		3015		L24	133	12100-N0102
									L28	130.35	12100-A8703
COMPRESSION RATIO USING HKS 1.MM HEAD GASKET FOR ABOVE COMBINATIONS
HEAD	#1	#2	#3	#4	#5		#6	#7	#8
E31	11.73	11.98	9.45	9.65	8.67		8.83	9.56	9.72
E88	11.24	11.48	9.14	9.33	8.41		8.56	9.23	9.39
N33	10.65	10.87	8.76	8.94	8.08		8.23	8.83	8.97
N33/P50	10.65	10.87	8.76	8.94	8.08		8.23	8.83	8.97
N42	11.26	11.50	9.16	9.34	8.42		8.57	9.25	9.40
N47	11.26	11.50	9.16	9.34	8.42		8.57	9.25	9.40
P81	11.26	11.50	9.16	9.34	8.42		8.57	9.25	9.40
P79	9.71	9.91	8.14	8.31	7.53		7.67	8.16	8.30
P90	9.71	9.91	8.14	8.31	7.53		7.67	8.16	8.30
P99	9.71	9.91	8.14	8.31	7.53		7.67	8.16	8.30

Courtesy of Jim Wolf Technology