Firewall

Hello All,
Happy Holidays! What size are the two holes in the firewall that the speedometer, temp sender, oil pressure line, choke and throttle cable pass through (1950 3100)? I have a smooth firewall and I need to drill both holes.

Thanks in advance,
Mike

 

Damn good question!

I don't know the answer because mine was pre-drilled at the factory!



What I would do is buy both grommets and take the inside measurement inside the groove and drill the holes accordingly.

Something to think about.

Ken

 

Just barely big enough for the grommets to go through.

 

The one closest to the center of the firewall is 1 1/8" dia., and the speedo hole is 1 1/6" dia. My firewall is stripped down w/o grommets so I had easy access to measure them.

 

Thank You! The grommets are on order otherwise I would have just measured the grommet itself. Be safe this New Year!

Mike

 

Check this out

Firewalls and connections, see attachment.

View attachment Firewall holes and connections.pdf

Haasman

 

Thank You!