Roller Lift Camshafts - Diesel/Gasoline Differences

86BUICK07
Bulletin 86-6-15

Date May '86

Ref. No. 86-116-6
SUBJECT: ROLLER LIFT CAMSHAFTS V-8 - DIESEL AND GASOLINE ENGINES

MODELS AFFECTED: 1981 - 1985 REGAL, LESABRE AND RIVIERA 1981 - 1984 ELECTRA


Roller lifter camshafts for 1981-85 V-8 diesel, and 1985 and later V-8 gasoline engines are almost identical, except for lobe contour and their fit to the camshaft adapter. Until recently, it was impossible to inadvertently install the wrong camshaft in an engine because:

- The adapter on a diesel engine is smaller and will not fit a gas camshaft.

- The adapter on a gas engine contains a pin that must fit into a hole. This hole is not drilled on a diesel camshaft.

Shortly, this pin will be removed from the gas adapter. It would then be possible to inadvertently install a diesel camshaft in a gas engine. This will result in poor performance and economy due to cam lobe contour differences.

Identification:

There is .015" difference between the adapter hole size. A gasoline adapter on a diesel camshaft will have a very sloppy fit. The diameter of the camshaft where it fits to the adapter is:

Gasoline - .951 - .952

Diesel - . 936 - .937