LQ4 Short Block - Engine Components - Test Results

All It Takes Is A Boneyard 6.0L Truck Engine With A Mild Hydraulic Cam, A 750 Holley Carb, And Headers To Get Some Serious Horsepower

CAMSHAFT	DURATION @ 0.050	LIFT (INCHES)	LOBE SEPARATION ANGLE (LSA)
'99-'00 LQ4, Int.	191	0.457	114
PN 12560967, Exh.	190	0.466
'01-'06 LQ4, Int.	196	0.467	116
PN 12561721, Exh.	207	0.479
GMPP Hot Cam, Int.	219	0.525	112
PN 12480033, Exh.	228	0.525

Gen III Family Tree
The following is a genealogy of sorts, listing the bore and stroke combinations for the popular GM Gen III engines. Starting with the 5.3L engines, the stroke is consistent at 3.622 inches, with the larger bore being the difference in the displacement.

ENGINE	DISPLACEMENT (CUBIC INCHES)	BORE/STROKE	COMPRESSION	ROD LENGTH
4.8	293	3.78/3.268	9.5	6.276
5.3	325	3.78/3.622	9.5	6.098
5.7	346	3.898/3.622	9.5	6.098
5.7	346	3.898/3.622	10.1	6.098
6.0 (LQ4)	364	4.00/3.622	9.4	6.098
6.0 (LQ9)	364	4.00/3.622	10.0	6.098

Test 1 was with the stock, iron 6.0L short-block and production iron heads assisted with a GMPP single-plane intake manifold, a 750 Holley carburetor, and a set of 131/44-inch Kooks long-tube headers.

Test 2 kept all the original changes from Test 1 but added the GMPP hydraulic roller Hot cam and valvespring kit.

	TEST 1		TEST 2
RPM	TQ	HP	TQ	HP
2,200	406	170	399	168
2,400	403	184	392	179
2,600	403	199	393	194
2,800	406	216	401	214
3,000	411	235	414	237
3,200	418	255	427	260
4,300	424	275	435	281
3,600	429	294	438	299
3,800	433	313	437	315
4,000	436	332	434	331
4,200	437	350	434	347
4,400	439	368	436	366
4,600	439	384	441	387
4,800	437	399	447	408
5,000	432	411	450	428
5,200	424	420	450	444
5,400	412	424	444	456
5,600	398	425	436	466
5,800	383	424	430	475
6,000	367	419	423	483
Avg.	417	318	428	336
Power/ci	1.20	1.16	1.23	1.32
(peak)

SOURCES
Federal-Mogul (Fel-Pro) 2-48/-354-7700 federal-mogul.com/en	Holley Performance Products 1801 Russellville Rd. Bowling Green, KY 42101 KY 42101 270-782-2900 www.holley.com
Kooks Custom Headers North Bayshore NY 866-586-5665 www.kookscustomheaders.com	GM Performance Parts www.gmperformanceparts.com
LKQ Chicago IL