I have been contacted with a question that maybe somebody here could answer.

The person who has contacted the Routemaster Association, has an AEC Regent V, but it has markings on it that make us think it is a former LT AEC AV590 engine.

Can anyone explain these markings ?

They are :

The engine block has been marked in paint with 'RM 128'. Along side the 'RM 128' on the block is BEA370 (could be REF 370) and TPIPBE, I think as its difficult to read. The number on the block is A2/17101.

Many thanks in advance !

My bus number (if any): RM1368

This enquiry hasn't originated from a company in Northfleet by any chance has it?

Would they have a 1960 Northern Counties bodied Regent V ?

My bus number (if any): RM1368

Andrew, the only way to establish whether the engine originates from LT is to check the engine number. You'll fine that that is stamped in small letters/numbers at the very top of the block, towards the centre. If you take a look at the engine codes for the AV590 (that can be found on this website http://www.rmoof.co.uk/Engine%20Codes.htm ) this will provide all the variants that LT used, and you'll be able to check if it was originally an LT engine.

For example the engine no on 1699 is AV590 1AHX5966 which if you refer to the table, is one of the later LT engine types (EN54). The no on my Eastbourne Regent V is AV590 1HX1727, a non LT engine that dates from 1961.

Hope this helps.

Cheers

Steven

My bus number (if any): RM1699, Eastbourne Regent V (KHC369) Eastbourne Regent III (AHC442)

It could be that the unit was overhauled by LT when it was trying find ways of subsidising the costs of Chiswick and Aldenham.
And true to LT form did a mix 'n match with the units.

Chiswick didn't do any "outside" engine work, LT Works were not allowed to do outside work unless there was "spare capacity". Aldenham did a few trailers for M&S on the paint line but that was about all. More LT engines went out from the garages to outside companies at the end than went to Chiswick. It's possible the block was from an RM though, REF was a common marking and referred to a particular planning sheet.

My bus number (if any): RTL 980, RMC 1458 RM 1585, M 961 and several RTs

Just before I left LT and was at Chiswick for a short while, they did try contracting for overhaul/refurbishment of other operators engines but restricted it to similar or same engine types as they did not want to invest in any additional tooling or skillsets.

I do recall several Leyland engines coming in whilst there were dozens laying outside removed from the overhaul cycle and recovered from scrap Leyland RMs. I often thought they could have overhauled them and sold them or supplied exchange units.

Then contracting out become the new flavour although BEL also tendered for such work.