Can anyone tell me what decking a block will do to it as far as horse power or torque? I have had different people tell me that it will increase both, decrease both, and increase one while decreasing the other.

 

From what I understand on the decking issue, its ultimate goal is to increase compression ratio. What it does is allow you to fine tune your block so that the top dead center of piston stroke is ideally located in relation to the deck. I could be wrong, but I think you want it to be like 0.020 down say. If it is 0.035 down, then there are points to be gained with your compression ratio, which can make the detonation in the chamber "hit" harder, which would raise your torque because the piston will be getting pushed down harder, which will thus raise your horsepower, because one is dependent on the other.

I am no expert, but I have done alot of reading one this, my take is that it really is not as simple as all that though. There is no shortcut like "decking my block will give me more horsepower", "getting higher lift rockers will give me more horsepower"... It seems to me like it is almost a crapshoot, or a science. Your best bet is probably to just find a good build that makes the numbers you want, and copy it. I'm in the process of trying to get a handle on it, and I have a funny feeling it is going to take a few years of tinkering, and studying, and thinking.

 

The whole decking the block thing is iffy. The whole purpose is to raise the compression which theoretically should should increase torque and horsepower both. Thing is youll always make more torque , but horsepower depends on a lot of other things. The cam heads and intake still effect figures.
Another thing you have to watch for is follow on issues such as intake. Usually the block is decked in conjuntion with the heads being shaved as well. With the right shaving a set of 10:1 pistons could make 11:1 fairly easy. but then you get into issues such as piston to valve clearance and pushrod length to avoid valve binding. Then theres always the issue of pump gas. I recommend really doing your homework on this if youre thinking about and decide what your car is really being built for. Hope this helps you.

 

Actually my block was decked by the previous owner. I had it built by someone who knows alot more than me and gave a warranty (as long as I wasn't racing) so I know it was done right. Mainly I was asking to confirm what I thought I already knew. I know how an engine works well enough to work on one but not well enough to select parts and build one. Maybe someday but I'm not there yet. Plus, I'm not looking to build the fastest car on the track, just something that will smoke the tires and turn heads when I pull up at Sonic.

 

Decking the block and or the head provides a smooth surface for the head gasket sealing. Performance gains relate more towards the effeciency of the combustion achieving the proper "squish" between the piston and the head will increase the effeciency of the burn and reduce the chance of detonation. The gain in compression of decking the block is minimal. This is a decent explaination http://www.digitalcorvettes.com/foru...p/t-86327.html

 

Ok, that's pretty much what I thought but it's been a long time since I was doing this sort of thing and It's hard to remember.

 

Decking and planing a block based off cam and crank centerline is the way to go. Most any shop can just shave the deck to ensure flatness for gasket sealing. When they do it based off of the crank and cam then they're insuring that the pistons all have the same distance in the hole and the same cylinder volume. It's basically blueprinting the block. When done with a professionally balanced engine you will notice a difference. The engine will be smooth and rev higher due to lack of fluctuation.

Stock blocks can be way off from one side to the other when looking at the crank centerline. The pistons come up further on one side than the other if that's the case. Even if you throw a balanced rotating assembly in there the compression will be off from one side to the other due to the differences in cylinder volume and how far the piston is in the hole at TDC.