Our Recommended Grommet for Multiple wiring uses:
• Wiring loom (usually PCM inside the cab) to the engine
• Through the floor or tunnel to the rear wiring
• Through the firewall to headlamps
Although these are stock size on the MGB models we convert, they are often used on just about any car that a hole can be punched of 1.75".
This plug allows the wiring from the engine bay to be run to the computer plugs by passing the wiring through the firewall. This allows the engine wiring to visually disappear when placing the plug in locations out of view, improving the cosmetics of the engine bay.
When using the BMC wiring loom with the Air Conditioning Option, Ordering Two or three of these plugs allows the engine to computer wires to be placed behind the dust cover of the wheel well.
Already fit the wires through the correct hole size but forgot the rubber plug? Although we avoid cutting these, not all situations allow to install the plug ahead of the wires. In these cases, we cut the "short" side of the grommet to the outer edge in order to slide the plug over the wires. To keep from the hole opening up with gravity pulling on the wires, do not make a large slot in the middle of the grommet- only the short side. Ta-Dah! Hot engine bay air held back from the cockpit.
Hole Size to Punch/Drill: 1.75"
Greenlee hole punch (Advertised size: 1-1/2") Actual Size: 1.95" hole.
We have used both a hole saw as well as a Greenlee brand Round knock-out hole punch. The Greenlee kits are used by electricians, and commonly by aviation technicians and fabricators. It's a cleaner punch, and requires less effort to make your hole.