Originally posted by LikeMy6
Brett,
stage motors were designed by Buick to run in off road competition and were not installed in any factory car. you could order them from Buicks parts division and very few people knew of them. The stage1 block was Buicks 1st attempt at making a stronger than factory production block they used modified production molds to enhance strength.As the designs progressed and changed the block was different than when they started they then dubbed it a Stage2. The main difference between the early Stage1 & 2's were the Machining and the main caps. Stage1 blocks had a factory oil pickup location,Stg2's didnt. Stg1 blocks came with 2 bolt mains but could be machined to 4 bolt center caps,the stg2 came this way and had Billet steel caps.Both blocks enjoy a solid Ribbed lifter valley(this is where a V motor tries to rip itself apart)this enhanced strength,decks were thicker more meat in most critical areas and thicker ribbing all over.All stage motors were designed for Big Horsepower,they have larger oil passages and were cast from a ChromeMoly Nickel Iron alloy to further strength.Stg1's were only drilled and tapped for 4 Head bolts per cylinder stg2's got 6.They came in 3.8 or 4.1 versions and were off-center just like production blocks.In competition they were used in Busch Grand National and made over 500hp NA style! they were used in Indy car as well where they seen turbo boost and made around 700hp! finally the end result was the perfected on-center stage2 Block with 4 bolt front and rear mains and 6 bolt centers!with a 3.625" stroke and 4+" bore 270+cid is the maximum that has been succesfully run making in excess of 1500HP in Kenny Duttweilers cars! Most stage motors used in Turbo Regals make at least 600HP with most in the 750+HP range. The most sought after block for most Buick TR owners is the 3.8 or 4.1 off-center because it can be easily disguised as the production motor by using the factory intake and head configuration. one of these blocks in vigin condition(which is almost impossible now) will fetch near $3000 or more!
That is what a stage Motor is!
Later
Frank