QA

Question: What Is Decking A Block

Decking the Block Decking is the process of cutting down the portion of the block to which the cylinder heads mate. This is important for several reasons. First, it is often necessary to remove some material from this part of the block just to “square up” the cylinder heads.

When should you deck a block?

If the block is NOT square it’s a no brainer, gotta deck it. If it is square and it passes a flat test using a straight edge and a feeler gauge there is no “normal” reason to deck it at all. If you want to get fancy and go for zero deck height (not a bad thing) or some other “race ready” reason, then deck it.

What part of the block is the deck?

Deck. The top surface of the block, where the cylinder head sits, is called the deck . It is machined perfectly flat and mated to the bottom face of the cylinder head . In between the block and the head there will be a head gasket .

What purpose does the deck of an engine block serve?

The deck plating process is used in applications where cylinder head pressures are greater than average, to ensure cylinder sealing and prevent scuffing of the piston against the bore wall.

Will decking a block increase compression?

Often, production engines can have as much as 0.020 to 0.040 inch of clearance between the top of the piston and the deck. Machining the block surface can reduce this distance, an operation referred to as decking. Reducing this distance increases the compression ratio.

What does it cost to deck an engine block?

Decking the block runs about $180. On the high end we have spent about $640; on the low end, $575. If the block did not need to be align-bored (honed), the cost would be $400 to $460. Also upgraded is the cylinder-boring process.

What is block decking?

Decking the Block Decking is the process of cutting down the portion of the block to which the cylinder heads mate. This is important for several reasons. Finally, a block must often be decked to achieve the proper deck height. Deck height is the distance from the crank centerline to the deck surface.

What is block deck height?

Engine block deck height is the distance from the centerline of the main bearing bore to the flat surface of the block where the heads bolt on.

What is a tall deck block?

– Tall deck blocks use a special intake manifold and distributor to allow for the additional height. Other than that many parts can be the same as a standard deck. – The ‘stroke’ of a standard and a ‘tall-deck’ 427 are the same, only difference is the piston.

What is considered the engine block?

An engine block contains the main components of an internal engine. It houses the water cooling system, crankcase, and cylinders and their components. The use of metal in its construction gives it strength and the ability to efficiently transfer heat from the combustion process to the main cooling system.

What is deck clearance on an engine?

Deck clearance is the distance between the piston deck at TDC and the deck surface of the engine block. Negative Clearance: The piston protrudes slightly from the deck surface. Positive Clearance: The piston sits a bit inside the cylinder bore.

What is the deck height of a big block Chevy?

Standard big-block deck height is 9.800 inches from the crank centerline to the deck surface, and tall-deck blocks like this one measure 10.200 inches.

What is engine deck?

For the record, deck height is the distance between crankshaft centerline and the top of the block. Deck machining and align boring can affect the overall deck height of any engine. Deck height dictates many engine dimensions. It limits stroke, rod length, and piston compression height.

How can I make my engine block stronger?

Some factory blocks incorporate “girdles” which significantly increase the stiffness of the bottom end of the block. On blocks not using a factory girdle, sometimes an aftermarket girdle or aftermarket steel main caps can be installed to strengthen the block.

What is the use of cylinder liner?

The cylinder liner prevents the compressed gas and combustion gas from escaping outside. It is necessary that a cylinder liner which is hard to transform by high pressure and high temperature in the cylinder.

How much does milling a head raise compression?

In the definitive milling test, there is an average of 2.6% HP increase per point of compression. In the less definitive test where three sets of heads with different combustion chamber volumes were tested, there is a 6.24% HP increase per point of compression.

How much compression should a SBC 350 have?

It’s likely that you have somewhere in the range of 150-170 psi.

What does decking a cylinder head mean?

Shawn, you DECK the HEADnot the pistonand its NOT adding material to it.its removing material from it..and its done for various reasons..if you over head an aluminum head and it warpsyou can deck it to flatten it back out..you can also deck it just to decrease the size of the combustion champer Feb 19, 2002.

Does hot tanking an engine block remove rust?

A hot tank really will not do anything to rust. If you can find a machine shop that uses an oven and steel shot blaster to clean cast iron, that makes it look like new.

How much does it cost to clean an engine block?

How Much Does it Cost to Have an Engine Cleaned? Surface (Top) Clean Top-to-Bottom Clean Average Cost (Low) $40 $145 Average Cost (Mid-Range) $55 $200 Average Cost (High) $80 $400.

How much does it cost to bore an engine 30 over?

How much does it cost to get cylinders bored? A good bore job around here costs $40 to 50 per hole for 4 stroke, and $50-60 per hole for a 2 stroke (2 strokes are more because of the time required to chamfer the ports).