November 2022 Shop Solutions - Engine Builder Magazine

November 2022 Shop Solutions

November tricks and tips for the shop!

LONG TAP EXTENTION

Chasing threads at the bottom of deep holes in engine blocks can be done with a pulley tap. Pulley taps are made with an extra-long shank. However, if you do not have a pulley tap, you can make a tap extension.                                                                                                                           Here’s how: Cut off the threaded end of a long bolt and drill a hole in the end of the bolt’s shank 1/2” deep. To determine the hole size, measure the distance across the flats (AF) of the tap’s square drive.

Multiply AF distance by 1.155 to find drill diameter (DD). Example: AF = 0.252” Drill size = 0.252” x 1.155 = 0.2916”. In this case, use a letter “L” size drill bit (0.290”). Set the tap’s square drive on the hole in the bolt; mark the bolt where each corner of the tap’s square is located. Using an angle grinder with a 1/16” wide cutting wheel, slot the bolt where marked, about 1/2” length. Slots should be just wide enough to let the tap’s square drive wedge into the bolt’s hole. 

Slot width is typically 0.196 x DD. Max slot width = 0.392 x DD. Example: typical 0.196 x 0.290 = ~0.057” and Max 0.392 x 0.290” = 0.114”. If you wish to permanently secure the tap, silver solder it in bolt. Otherwise use the tap with the wedge fit, or with cured red threadlocker.

Tom Nichols, Automotive Machine & Supply, Joshua, TX

OTTER USE THIS SEAL

If you are rebuilding Ford V8 marine engines from the ‘80s and ‘90s, the marine reverse rotation 1-piece rear main seals can be expensive and almost impossible to find. The late model PTFE rear seals are non-directional and make a great seal to use in these applications. The PTFE option will work great on your late model GM marine engines as well. Always follow the manufacturer’s installation instructions.

Dave Sutton, Sterling Engine Parts, Minneapolis, MN

RUST PITS

When rebuilding vintage engines, a person must deal with rusty components. When I have rust pits in the cylinders that do not require sleeving, I treat them with rust dissolver jelly right before honing. It may take a few times to get it and a small stainless brush helps. I believe it stops the rust and oil spots right after final washing. I’ve had engines on the stand for many days and even weeks without the pits growing or showing rust – in my experience anyway.

Randy Torvinen, Torvinen’s Machine, Menahga, MN

REVERSE SCRIBE TOOL

When port matching intake manifolds, I make some different shaped “Reverse Scribes” to get in and scribe mark the dye on the intake manifold flange side. It works great, is often easier than marking and transferring an intake gasket pattern, as this gives you a real time indication of where to port to. Sometimes transferring a gasket can allow for some misalignment if you’re not 100% right on. 

Ron Flood, Cedar machine, North Branch, MN

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Shop Solutions November 2023

Many times, the flange diameter of the rod nuts will contact the radius around the nut seat on some rods. Some jobs may not warrant the expense of spot facing the nut seat on the connecting rods. In that case, it can be quicker and more effective to just machine a chamfer on the ARP rod nuts.

Engine Builder and Engine Pro present Shop Solutions in each issue of Engine Builder Magazine and at enginebuildermag.com to provide machine shop owners and engine technicians the opportunity to share their knowledge to benefit the entire industry and their own shops. Those who submit Shop Solutions that are published are awarded a prepaid $100 Visa gift card. Submit your Shop Solution at [email protected]. You must include your name, shop name, shop address and shop telephone number. Submitted Shop Solutions not published will be kept on file and reevaluated for each month’s new entries.

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