The Triumph 2000 / 2500 / 2·5 Register Forum

In my quest to buy a MB block, I nearly ended up with an early ( narrow bearing / external breather ) MB. What commission number did these end at; and why didn't they change the number to MC or something, when they changed the casting. MB must have originated from the Standard Vanguard.

Steve Knight wrote:In my quest to buy a MB block, I nearly ended up with an early ( narrow bearing / external breather ) MB. What commission number did these end at; and why didn't they change the number to MC or something, when they changed the casting. MB must have originated from the Standard Vanguard.

There are at least 3 Mk1 blocks and I think they can all be prefixed MB - only the very last Mk1's had MC

1963-1966 ish MB1 to about MB33408 Two inch mains - external breather and wee little followers
1965-67 MB 33409E up to MB 70000 I think Two inch mains - external breather and 0.800" followers
1967-1969 same mains as Mk2 and 2.5 - no extermal breather and 0.800" followers

Which type of the three listed by Andy are you after Steve?

Colin.

Hi Colin, I need one (or two) MB block 1967-8. These are the lightest that will take a 2.5L crank, despite the short 2L bores. I've been looking for years - but of course distance / transport is the problem !

My spare engine for the Mk1 may be one of these - I need to remember where I put it and then check what it is.

I bought if for the larger cam followers when I was going to build a really hairy motor for the Webers etc. for the Mk1 and frighten everyone (you?) with mad rally driving. Running the CMSC and AHMSC meant that I never had time so it has sat in one of the garages doing nothing.

My plans now are to keep the Mk1 with as much original 1964/65 stuff as possible and its original engine set up properly to run with the Webers - purely for fun and without serious competition in mind - so this engine will be surplus to requirements.

Are you interested if it is an MB? We can no doubt sort out a deal that does not involve money changing hands

Ted

Steve,
MB42669HE any good? No head and dirty in bores (some with corrosion) and 'hole' where tappets are but dry stored most of the time. In my opinion perfect for a rebuild.
Ted

MB 42669 ? Does Andy say these are external breather until MB 70000. By external breather I mean a pressed steel part connected to the outside of the block ( just behind the fuel pump ) I assume later blocks had more drillings / holes lower down, so as to allow breathing up through the rocker cover.

My early Mk1 Parts Manual actually lists a blanking plate and gasket for the hole that this breather fits over - later engines don't appear to have any hole so presumably breath through the top anyway.

It would be impossible to fit this aluminium casting with a pipe out of the bottom with the PI MU being in the way, but they probably found the external breather was unnecessary anyway so deleted it to commonise the blocks and relied upon top end breathing and recirculating crankcase gases through the engine as became the norm with other engines to reduce emissions.

Ted

Steve Knight wrote:MB 42669 ? Does Andy say these are external breather until MB 70000. By external breather I mean a pressed steel part connected to the outside of the block ( just behind the fuel pump ) I assume later blocks had more drillings / holes lower down, so as to allow breathing up through the rocker cover.

Pretty sure external breather means 2" mains ie no good for a 2.5