Inspection: Vacuum Check That Engine (#14) - Engine Builder Magazine

Inspection: Vacuum Check That Engine (#14)

I have found a few brand new castings to have porosity holes in them after they were torqued down. All of these heads were aluminum SB Chevy heads and were made overseas. These heads were “good” prior to proper installation.  

More than once I’ve found brand new water pumps to have leaking seals at the weep holes. Air is much less dense than water, so any small leaks are easy to find. With my vacuum pump I can check all freeze plugs, galley plugs, intake and head gaskets (for sealing) and block and head castings.

For a test, we took a freeze plug and drilled a .006? hole in it and it failed miserably. We have even used the pump as a “reverse” pressure tester on cylinder heads where we couldn’t find an external leak, but knew the head was bad. It’s sort of a second opinion that confirmed our suspicions.

Jeff “Beezer” Beseth

BeezerBuilt, Inc.

Newtown Square, PA

You May Also Like

Shop Solutions July 2023

Engine and machine shop tips and tricks.

BOLT COLLET

To precisely shorten bolts in the lathe, I made slotted collets for each bolt diameter. They are fractional in length to measure off the end, so you know where to cut for your length. I’ve used large O.D. valve guides and aluminum round stock. Just make the collet big enough to clear the bolt flange, hex or socket head.

Shop Solutions June 2023

Engine and machine shop tips and tricks.

May Shop Solutions 2023

Engine and machine shop tips and tricks.

April Shop Solutions 2023

Engine and machine shop tips and tricks.

Shop Solutions March 2023

If I’m not using torque plates, I tape up both sides and trim out the bores. I use painter’s tape, which comes off easily and doesn’t leave any glue residue. I get much less oil in the spray washer this way.

Other Posts

Shop Solutions February 2023

Check out February’s shop tips and tricks.

Shop Solutions January 2023

Next time you have set of large journal small block Chevy connecting rods to resize, consider honing the big ends of them for a +.002” outside diameter bearing that the LS engines with fracture cap rods use.

Shop Solutions December 2022

Everyone misses occasionally, and this helps avoid dents and damage.

November 2022 Shop Solutions

November tricks and tips for the shop!