Any AEC engine experts?

I am new on here and am looking for some help regarding AEC engines! I have the chance to rescue a 1967 RML Routemaster bus that is heading for the scrap yard, it has been vandelised, windows broken and is missing engine/gearbox etc. but apart from those minor issues looks to be a solid and tidy example.
Question is how similar is an AV505 dry liner engine to an AV590 wet liner engine, power and torque look to me to be comparable but what about bell housing bolt pattern, length and general layout? The limited info I can find suggests that the 505 was a development of the 590?

The reason I ask is because I can buy a 1967 Merryweather fire engine with a “running” 505 but cannot easily find a good 590 or 690…

This bus had been retro fitted with a ■■■■■■■■ (C series?) whilst in service,

The automatic remote mounted gearbox would be the next problem,

although I could maybe convert to manual using the fire engine box, as a long shot.

matchless:
I am new on here and am looking for some help regarding AEC engines! I have the chance to rescue a 1967 RML Routemaster bus that is heading for the scrap yard, it has been vandelised, windows broken and is missing engine/gearbox etc. but apart from those minor issues looks to be a solid and tidy example.
Question is how similar is an AV505 dry liner engine to an AV590 wet liner engine, power and torque look to me to be comparable but what about bell housing bolt pattern, length and general layout? The limited info I can find suggests that the 505 was a development of the 590?

The reason I ask is because I can buy a 1967 Merryweather fire engine with a “running” 505 but cannot easily find a good 590 or 690…

This bus had been retro fitted with a ■■■■■■■■ (C series?) whilst in service,

The automatic remote mounted gearbox would be the next problem,

although I could maybe convert to manual using the fire engine box, as a long shot.

Is there any reason why you wouldn’t want to put another ■■■■■■■ engine into it? It think it will have been the B series engine as opposed to the C series and there is no shortage of availability of these out there.

From what (little) I have read the ■■■■■■■ was a poor fit, tight to the bulkhead and with the diesel pump on the drivers side etc. plus getting hold of a retrofit kit of engine mounts, bell housing etc. to fit the ■■■■■■■■ may be harder that using original 590 parts on the 505■■?
■■■■■■■■ Scania and Iveco were retrofitted to get the emmisions down for London use but nowdays the look and sound of an AEC is much appreciated.
I believe it was the C series that was retrofitted, probably in the late 90’s.

Without insulting anyone else on here i think Cav would be the one to put you right , i know he mentioned on another thread that some had fitted AV 760s in their Routemasters with disastrous results not sure why they didn’t use AV505s

The AV/AH 509 and AV/AH 505 are indeed different in specs, the 590 and 690 were introduced at the time of the MkV AEC models. Where you may find problems is what you already suspect Flywheel, Clutch and Bellhousings of different size etc, probably better to keep the 505 engine and it’s gearbox as one, presuming of course this whole unit would fit into the Routemaster. I never worked on AEC Buses only the goods range, however I’m not sure where you got your info on the 505 being a development of the 590 but rather it was a development of the 470 to 471/505, therefore its very likely there are differences between the older 590 and 505 which was new to the Ergomatic cabbed models. There may be no quick answer to this unless someone on this site has more knowledge and will possibly rely on taking measurements etc to see if putting the 505 into your Bus is feasible. Good luck Franky.

A long shot maybe, or perhaps you’ve already tried, but hundreds of Routemasters were dismantled in the breakers yards around Barnsley over the years, maybe one or more of the yards might have an engine or two (or even some buses) on hand. Try looking up PVS Ltd., Geoff Ripley or Trevor Wigley, or google ‘bus breakers near Barnsley’ Good luck!

Oh dear where do I start! perhaps with: " you can’t save them all". Then “how much money have you got” and " have you got secure undercover long- term storage with a concrete floor and electricity?" It looks like someone has already started on cannibalising it to keep others going - which quite frankly is the way things are going to go. There were the best part of 600 of these buses withdrawn between 2003 and 2005, That’s 18 to 20 years ago and for most of that time I have made my living keeping these things going, it is getting harder and harder. The vast majority of these still exist and all are looking for, mostly the same, obsolete parts to keep them running.

So, Have you made a list of what is missing? do you know what you are looking for to see if it is missing? Is it really just the engine and gearbox? If the gearbox is missing and it was a ■■■■■■■ C engine then the brake system hydraulic pump and its Quill drive assembly will be missing as will the gearbox air system Compressor (unobtainable) ( I would suspect that someone took the decision that there was some reason to rob this particular bus. My guess is that that apart from the radiator (£700) the special ■■■■■■■ Front engine mounting cross member is missing along with the propshaft (circa £400), the gearbox ECU (£■■*?), the power steering ram ( circa £900 I think), the footbrake valve (£2000) and the 2 brake accumulators (£500 each) . Given the legal opportunity and facilities I’d have had the rear coil springs and the diff out as well and the half shafts too - these last get stolen to order. The seat frames get junked by body shops doing conversions to mobile bars, cafes etc. And then you have the condition of the rear chassis subframe ( the B frame) to consider which may be the reason why it has been cannibalised.

How to confirm which engine it had: There were two ■■■■■■■ engines fitted as well as Iveco and Scania units. IIRC there were only one or two RMLs with B series engines anyway. The ■■■■■■■ C engine required significant surgery to the cab firewall to make it fit in the space, there will be a stepped relief at the bottom of the firewall to clear the exhaust manifold. The rear engine x member is rectangular in section. Inside the cab the gear selector will be atttached to the steering column rather like an old column change lever in a '50s car. The B series ■■■■■■■ will have a plastic push button assembly in the same place or a modern indicator stalk.

Yes you could engineer an AV 505 in to the bus, but you would have to carry out significant modification to the sump to make it fit in the bus, drill & tap the block to fit mounting studs in several places and obtain a fluid flywheel and the correct automatic gearbox. IIRC the pilot bore in the rear flange of AEC crankshafts is a different diameter for manual and automatic transmission applications - definitely the case with the AV760. A manual gearbox would require a clutch operating mechanism and a gear linkage which would be a real headache to engineer. So in reality you need a ■■■■■■■ C series Engine and its special Routemaster spec Voith fluid coupling which replaced the original Leyland rationalised fluid coupling which gave so much trouble when these engines were initially installed in the 1990s.

I haven’t done much to RMs since covid and I’m surprised just how much I’ve forgotten. Iv’e just googled RM gear box and it’s come up with D182 and I don’t recall that being the correct AEC type designation.

Worldwide and in the UK a variety of engines have been fitted to these buses. Leyland as an original fitment, ■■■■■■■ C, ■■■■■■■ B, Iveco 0836.1, Scania DS 9 Caterpillar 3306?, DAF 11.6, even a Gardner - in Singapore I think.

Ask carryfast what he doesn’t know isn’t worth knowing

Have you tried workington heritage bus Trust.
It’s run by volunteers but I imagine collectively there will be a lot of knowledge there.

I know you’ve worked on AECs for many years , do you know if the AV691 was fitted to the MKV MMs . I’ve just read that they weren’t but the later AV760 was. Is this correct ?