help w headgasket selection.

IHateHacks · 01-23-2007, 03:02 PM

On many street-driven vehicles, where master cylinders and other items protrude into the engine compartment, it's probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car. For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine (especially a racing powerplant which must be serviced frequently and quickly!) with the cylinder head and gasket assured of proper alignment. Studs also provide more accurate and consistent torque loading. Here's why. When you use bolts to secure the head, the fastener is actually being twisted while it's being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a relaxed mode, never crank it in tightly using a jammed nut. The stud should be installed finger tight then, when applying torque to the nut, the stud will stretch only on the vertical axis.

Studs are much more difficult to install with the engine in the car, but are stronger and less prone to stretching. Head Bolts will be easier to install with the engine in the car, but are not reccomended for high-boost applications. On the 7MGTE engine, the most common source of headgasket failure is due to the factory head bolts stretching and failing, therefore, when replacing a headgasket, ARP hardware is a must.

JSCSpeed.com gets credit for this.

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01-23-2007, 03:02 PM	#10
IHateHacks 20psi boost Join Date: May 2006 Location: New Haven/Hamden Posts: 793	On many street-driven vehicles, where master cylinders and other items protrude into the engine compartment, it's probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car. For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine (especially a racing powerplant which must be serviced frequently and quickly!) with the cylinder head and gasket assured of proper alignment. Studs also provide more accurate and consistent torque loading. Here's why. When you use bolts to secure the head, the fastener is actually being twisted while it's being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a relaxed mode, never crank it in tightly using a jammed nut. The stud should be installed finger tight then, when applying torque to the nut, the stud will stretch only on the vertical axis. Studs are much more difficult to install with the engine in the car, but are stronger and less prone to stretching. Head Bolts will be easier to install with the engine in the car, but are not reccomended for high-boost applications. On the 7MGTE engine, the most common source of headgasket failure is due to the factory head bolts stretching and failing, therefore, when replacing a headgasket, ARP hardware is a must. JSCSpeed.com gets credit for this.