Redrill 1HZ flywheel for 300mm clutch?

[gifu]

Has anyone ever redrilled a 1HZ (275mm) flywheel to accept a 300mm clutch cover?

Why would I bother? Because the 275mm flywheels are sorta worthless… and the 300mm flywheels are $700-800.

 

[mudgudgeon]

Which gearbox do you have?
What are you trying to achieve apart from saving money?

Are you talking about a used 1hz flywheel? Or new one?

The 275mm flywheel/clutch was mated to H150F 5 speed that has a 21 spline, thin input shaft.

The 300mm flywheel/clutch was mated to H151F that had a thicker 14 spline input shaft.
If you're trying to upgrade the clutch in a 1hz to 300mm you'll have to find the right clutch.

Also, the flywheels have a raised wear section that the clutch friction pads contact. This is different between the two.

300mm flywheel below
The raised section in the 275 unit is a lot narrower (25mm smaller diameter)

 

[gifu]

I’m trying to find a use for my stack of 1HZ flywheels. And save money on 300mm flywheels.

 

[mudgudgeon]

I’m trying to find a use for my stack of 1HZ flywheels. And save money on 300mm flywheels.

I think the biggest hurdle is the raised fiction surface is different.

Another option is source upgraded 275mm clutch to suit your application.

There are 275mm clutches available to suit the 14 spline H151F if that's what is needed.