How do i check the deck height with the crankshaft out of the block? I work in a machine shop (industrial not automotive) and have access to some inspection tools. It is a factory block and i want to know exactly what the deck height is before i move any further with my project.

Brandon

 

No one has the answer to this? I would like to do this tomorrow while i have some spare time (which is very limited by the way).

Any help would be great!

Brandon

 

This is a fairly tricky operation if you don't have the right measuring equipment. It is not for the faint-of-heart or poorly equipped person. If anyone has a simpler approach, I'm open to correction.

1. Unless you've had the block squared by a reputable machine shop this is a waste of time. The process requires truing the main bores with align hone and then cutting both of the deck surfaces parallel to the mains. It's critical that the deck be cut to the same block height on both banks.

2. To check the block height, measure the distance from the block deck to the crankshaft centerline. Note that this is the "block height". Be sure that you measure on a line that is perpendicular to the block surface. Do all four corners so that you're sure that the decks are cut "on the square."

3. Measure the center-to-center length of the rod. Don't assume that all rods listed as 5.7" or 6" are exactly what they say. Don't assume that just because one rod in a set measures 5.7", that they will all be the same. If they are, good for you.

4. Measure the stroke on each throw of the crankshaft. Divide the actual stroke by 2.

5. Measure the compression height of each piston (centerline of the wrist pin to the flat surface on top of the piston. There may be small variations in compression height, depending on the precision of the machining process at the factory.

6. The formula is: deck height = block height - rod length - compression height - 1/2 stroke.

Look for variations that would indicate that the deck is not cut precisely parallel to the crank (deck heights that are smaller on one end of the block than the other. You can match parts to achieve the most precise number possible if you have found variations within the rod lengths and/or compression heights.

In the end, it's a hell of a lot easier to mock up the assembly and just check the actual deck.

Good luck.

c

 

Thanks for all the information. I learned a lot from that. I guess i may have my terms wrong though. I guess what i am actually looking for is the block height right now. I need to measure it on all 4 corners and see how close i am to the theoretical 9.025" height from the factory.

Brandon

 

You DO NOT want to deck a block unless it is mocked up and deck height is measured WITH THE CRANK,ROD,PISTON YOU ARE GOING TO RUN !!!!


DO it at all 4 corners and square deck the block.

David

 

What kind of inspection equipment, CMM?