Torques and Patterns for most Buick Engines

The following torques and torque patterns were compliled with the help of Todd.

I was finally able to go through all the shop manuals from 53 to 67. In all cases, the left head is the same part as the right head, except for maybe a water jacket plug that has to be reversed depending on L or R side usage.

Pre-tightening is done by going around the bolt sequence three times, gradually increasing the torque on each round. Post-tightening is specified for most engines, where the bolts are to be torqued again to the final value after the engine is up to full operating temperature. Perfect Seal sealing compound (Buick part #980456) is specified for use on the bolts in some cases. This would be whereever the bolt hole in the block goes through to the waterjacket.

There are probably some minor errors in the shop manuals which appear in the following specs. Some years showed different torque ranges in the same shop manual. There is some confusion as well when the number of bolts were reduced in the smaller engine sizes. These are things I couldn't prove out by going to parts lists, photos, or other books.

Todd

Engine Torque Specifications

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Buick Straight Eight

MODEL	CYLINDER HEAD	ROD BEARINGS	MAIN BEARINGS	CRANKSHAFT BALANCER	FLYWHEEL	MANIFOLD	REFERENCE
263/320	65 - 75	263 40-45 320 60-65	90-100	100-110	sync. 35-40 dyna. 50-55	25-30	1951 shop manual

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Torqueing the Nailhead

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215 V8

Torque was 50-55 for the 61 and 62 models. The 63 model required 65-75. There was a Buick service letter put out many years later which rasied the values on the earliest years of the 215. All years had 14 bolts. Post-torqueing is not specified. Perfect Seal is specifed for all years. The tightening order is the same as the late model nailheads.

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198 V6
In 1962 and 1963, 65-70 is the given torque value. These engines had 11 bolts per head. Post-torqueing is not specified. Use of Perfect Seal is specified.

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225 V6
The 1964 and 1965 225 V6 use a torque value of 65-70. They had 11 head bolts and used the same pattern as the 198 (above). In 1965 The Torque was increased to 70-75. In 1966 the head went to 8 bolts, the torque continued to be 70-75. In 1967 the torque specification was changed to 65-80 and retorqueing was specified.

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300, 340 V8
In 1964 the 300 shows 14 bolts and used a torque of 65-70. It used the late model nailhead torque pattern (shown above). Post torqueing is not specified, Perfect Seal is.

In 1965 the 300 shows 10 bolts and increases the torque to 70-75.

In 1966 torque goes to 65-80 and in 1967 post torqueing is specified.

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Buick 300 - 340

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