Robroy
06-26-2007, 04:37 AM
Thought I’d share this information about the GM big blocks that I found on Ebay. Some interesting stuff is in it, especially about swapping heads and about the oiling system.
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Buick
Buick made do with the "nailhead" 322, 364, 264, 401, and 425 engine family from 1953 through the '66 model year. The new-for-'67 Big Block engine was produced in 400 (to replace the 401) and 430 (to replace the 425) cubic inch versions, sharing the same stroke of 3.9" which although short for big-block engines in general, was longer than what was used in the older engines. The engines have a large bore-to-stroke ratio, with the bore of the 400 measuring 4.040", and 4.1875 for the 430.
Buick expanded the 430 by opening up the bore to 4.312 for the 1970 model year. The 400 and the 430 were then discontinued. The 455 uses a different scheme to supply oil to the rocker arms than the previous big block engines. Starting in '72, blocks were slightly re-designed in the head gasket area. In short, you must be very careful when swapping heads from one engine to another, to assure that the oiling system, coolant passages, and head gasket are compatable with one another.
Buick big-blocks have forged steel connecting rods, although small-blocks use cast iron rods. Even fans of the Buick engine note that oiling system problems are the first thing that needs to be addressed in a performance application. Poor oiling system performance is hard on the front cam bearing, and on most all of the crank bearings. Aftermarket fixes are readily available, but in general high-volume oil pumps are not recommended due to excessive loading and therefore wear on the distributor/cam gear interface. Fixing the oil system troubles added to "normal" high-performance modifications and expert machine work can result in surprising power--Buick enthusiasts think of a 455 as a "Chrysler Hemi"-killer, and with some justification.
The Buick big-block engine family is identified by:
1. Distributor in the front, offset to the left (driver's side) and tilted to the left about 30 degrees. Distributor rotates clockwise. Distributor does not enter the intake manifold, it enters an aluminum front cover assembly that is bolted onto the front of the block.
2. Valve covers have 5 bolts, two on the lower edge, and three on the upper edge. (Small block Buick 350s have 6 bolts, three in the upper row, three in the lower row. Buick 300 and 340 engines use four bolts.)
3. Timing chain cover is aluminum, and also has the oil pump housing cast-in. Fuel pump is on the left (driver's side.)
http://reviews.ebay.com/GM-Big-Block-455-engine-families-A-primer_W0QQugidZ10000000002053785
.................................................. ..............................................
Buick
Buick made do with the "nailhead" 322, 364, 264, 401, and 425 engine family from 1953 through the '66 model year. The new-for-'67 Big Block engine was produced in 400 (to replace the 401) and 430 (to replace the 425) cubic inch versions, sharing the same stroke of 3.9" which although short for big-block engines in general, was longer than what was used in the older engines. The engines have a large bore-to-stroke ratio, with the bore of the 400 measuring 4.040", and 4.1875 for the 430.
Buick expanded the 430 by opening up the bore to 4.312 for the 1970 model year. The 400 and the 430 were then discontinued. The 455 uses a different scheme to supply oil to the rocker arms than the previous big block engines. Starting in '72, blocks were slightly re-designed in the head gasket area. In short, you must be very careful when swapping heads from one engine to another, to assure that the oiling system, coolant passages, and head gasket are compatable with one another.
Buick big-blocks have forged steel connecting rods, although small-blocks use cast iron rods. Even fans of the Buick engine note that oiling system problems are the first thing that needs to be addressed in a performance application. Poor oiling system performance is hard on the front cam bearing, and on most all of the crank bearings. Aftermarket fixes are readily available, but in general high-volume oil pumps are not recommended due to excessive loading and therefore wear on the distributor/cam gear interface. Fixing the oil system troubles added to "normal" high-performance modifications and expert machine work can result in surprising power--Buick enthusiasts think of a 455 as a "Chrysler Hemi"-killer, and with some justification.
The Buick big-block engine family is identified by:
1. Distributor in the front, offset to the left (driver's side) and tilted to the left about 30 degrees. Distributor rotates clockwise. Distributor does not enter the intake manifold, it enters an aluminum front cover assembly that is bolted onto the front of the block.
2. Valve covers have 5 bolts, two on the lower edge, and three on the upper edge. (Small block Buick 350s have 6 bolts, three in the upper row, three in the lower row. Buick 300 and 340 engines use four bolts.)
3. Timing chain cover is aluminum, and also has the oil pump housing cast-in. Fuel pump is on the left (driver's side.)
http://reviews.ebay.com/GM-Big-Block-455-engine-families-A-primer_W0QQugidZ10000000002053785