[928uk] Clutch master cylinder

[jonathanrackowe at gmail.com]

Hi Mike,

I'm a bit confused by you saying that reducing the bore diameter of the clutch master cylinder will give quicker clutch action.

For a given clutch pedal travel, you will move less hydraulic fluid with a smaller bore m/cyl, so the clutch SLAVE cylinder rod won't move as far. i.e. You need to move the clutch pedal and m/cyl rod further to get the same resultant clutch movement as original. Pretty sure that makes the clutch action slower than original.

Pedal effort with a smaller bore m/cyl would be less, not more, but over a longer distance.

I would have thought that honing of the clutch master cylinder bore, and if made significantly larger use of matching larger diameter seals, would be a better way to go than sleeving it.

Is it possible that you actually had your clutch slave cylinder sleeved, in which case all that you wrote then makes sense?

Best regards,
Jonathan
 





-----Original Message-----
From: 928uk <928uk-bounces at lists.928.org.uk> On Behalf Of Mike Miller via 928uk
Sent: 19 January 2025 20:50
To: benhodges1975 at gmail.com; 928 Org <928uk at lists.928.org.uk>
Subject: [928uk] Clutch master cylinder

I had mine stainless steel sleeved and reduces 1 size in diameter to give
quicker clutch action. Little adjustment on the assist spring and pedal
effort quite acceptable even for an octanagerian.
Mike Miller Brisbane 82s 5 sod