You're right, Blazer. I've changed my opinion of the first shop a bit after spending time at the machine shop while decking the block a few days ago.
The damage to the engine block deck between cylinder 3 and 5 was about .012" deep, but the shop operator told me that he expected more material would be needed to be removed than that. Reason: few blocks are anything close to square. Whether it's because of machining tolerances at the factory or heat/cool cycles during the many miles a vehicle is used, he wasn't sure, but as it turned out he was right. My block on both banks was higher at the bell housing end than at the front. The driver's side deck had an extra bonus--it also was higher on the valley side than on the exhaust manifold side. It really shows how sloppy the fit can be and the intake manifold gaskets still take up the slack, so the guy at the first machine shop I talked to maybe knew what he was talking about, much as I hate to admit it.
Anyway, the block is now decked and waiting for the next step. This step is to check the alignment of the main bearing bore. Unfortunately, this step will have to wait until the first of the year as the operator will be gone until then. So until then, here's some photos of the decking operation.
The engine deck grinder.
Here's the grinder head and the 10 grinding stones. These stones rotate within the circular guard. The head only travels up and down; the bed of the machine, where the block gets positioned, reciprocates horizontally and moves the block under the grinder head. With each reciprocation of the bed, the grinder head drops down a pre-set amount, in this case it was .002". It took about 20 minutes a side to deck the block, but the entire operation took far longer due to block setup in the grinder.
The block is being positioned in the deck grinder.
Water, with a rust inhibitor, is used as a coolant while the block is being decked. Even with the water on, sparks still fly.
From time to time, the operator takes a measurement using a dial indicator placed in a measuring jig. When the deck is nearing its final height, the operator slows down the feed of the bed while the grinder head maintains its speed. This puts the required finish on the deck.
After both decks have been ground, the block is taken to the pressure washer. Here, the block sits on a turntable and is spun slowly while near boiling water and detergent is sprayed upon it under pressure. After a set time, the detergent is shut off and just hot water is used as a rinse. Then, out comes the hot block in a haze of steam, incredibly clean and new looking. The block would soon rust, but it is quickly dried off with compressed air and then sprayed with WD-40.
And that's the state the block is now in; I'll get back at it in about 2 weeks.
The cost of getting the block decked was $100.
