Awakening a Holt 75 Engine from a Nap?

Very nice looking gaskets - Hard to cut that one without tearing the material. Looks like Hobby Lobby on part of your kit? Share the information on what you found to cut those. - Keep up the good work. - cts

CTS- thanks for the compliment. I’m a bit of a perfectionist and won’t accept half-baked attempts. The scrap pile was larger than the completed pile..

Yes, Hobby Lobby and Michael’s for the cutting mat, rotary cutter and craft knife. I had to go online to find the OLFA compass cutters. I already had a selection of gasket punches for the bolt holes. I invested in all new craft stuff as this probably won’t be the last time I cut gaskets…

The kit includes:

Friskars Softgrip detail knife

28MM rotary cutter

12” square cutting mat

6” and 12” clear rulers

OLFA CMP-1 compass cutter

OLFA CMP-3 compass cutter

I found the rotary cutters worked better on the 1/8” material, but would not work on the Karropak. The Karropak would only cut cleanly with the hobby knife or razor blade.

On second reading of your question CTS:

I cut the carb throat/venturi gasket rings based on a tip from BruceP. He suggested that these carbs will run extremely lean if that gasket doesn’t seal (part “N” in the cutaway view of the carb). I measured the space for this “N” gasket between the carb lid and bowl to be about 1/16” (somewhere between 0.060 and 0.065 with feeler gauges). With the addition of the 1/16” bowl gasket, that “N” gasket needed to be 1/8” thick. I also have more 1/16”, 3/32” and 1/8” gasket material. The thickness of the “N” gasket may change if 1/8” doesn’t seal well enough.

For the cutting of the gaskets, I cheated a little bit. I know enough CAD to draw out stuff 1:1. I spent some time with the carb and a set of digital calipers to draw everything. That gave me the ability to get all the curves and tangents correct. The outlines were printed and used as a template to cut the gasket material. A little fusion of new and old techniques.

BigSKyTR6 -- You are fortunate to have the knowledge of CAD and the technology associate with these "new" processes. Many of us rely on a punch if we have them or a piece of pipe, tubing, etc and a ball peen hammer. If you have mind to do so, and have the drawings to scale for the gaskets on this or other Caterpillar equipment, you might consider submitting them to the Library. They would be very helpful to others. Thank You for sharing! -- cts

CTS - I have tapped out gaskets on cast iron before. However, since this engine is 100+ years old and parts are exceedingly rare, I decided to measure everything. I did want to risk damage to any of the brass castings

This is the first Caterpillar (or CAT adjacent machine) I have wrenched on. Let me verify the gaskets all fit properly before committing anything to the library.