Hi ,
Out of interest only . When LT started putting Iveco engines in 'original' RM's was there much work required to do this to fit the engines in and was any other work required as part of the conversion . This is just for an original bus not a refurb .

Thanks

Mark

My bus number (if any): RML2391

Mark

My RCL is fitted with the Iveco engine ( only one so fitted I believe ), not sure when the conversion was carried out. It looks quite straightforward, usual mounting changes but retains the original flywheel setup. The exhaust is pretty tortuously routed from the nearside, and seems larger than the Cummins in diameter from what I remember. Disadvantage is the injection pump is difficult to access being on the offside of the engine. The cardan shaft looks as if it is the original length, although the Iveco is a little shorter than the AEC, I think. There are changes in the starting circuit wiring, with a relay in the ignition warning light circuit, but no start inhibit ( there will be when I wire it in ).
I'm sure one of the ex LT guys will have the correct information, but I cannot see that it would have been particularly difficult to achieve from an engineering viewpoint.

My bus number (if any): RCL2250

The then London Regional Transport looked at several alternative engines and used several service RMs as testbeds. I think they all were based at Victoria plus one or two in the sightseeing fleet at Wandsworth.

The only one I had experience of was I think RM 545 which I recall was a very well engineered DAF. But although very well revised was too expensive for the extreme penny pinchers that LRT were at that time.

I thought that start inhibit was part of the original gear selector wiring but with Ed's recent comments I am doubting my memory. I will have to dig out my drawings and take a look. The refurb buses do it through the gear panel but I didn't think that was the case with the original system.

Mark.
If you do change your engine the wiring mods could actually be minimal. The existing switch on the arens cable could be retained to "latch in" the vehicle (or switch on the ignition if you prefer) and the old type starter switch could still be used for starting.
If the new fuel solenoid is energised to run this will work perfectly (a relay may be needed if the run current is a bit more than the switch can take).
If the solenoid is energise to stop the engine (I believe the Scania engines are like this) then a stop button would need to be fitted but that could be hidden. That would give the same look and feel as it has now apart from the hidden stop switch. It may also be possible to not have a stop solenoid but with modification retain the mechanical connection of the original arens cable then in fact no electrical changes would be required at all for starting and stopping.

Charging wise I assume you would have a new internally regulated alternator. In that situation removal of the regulator would be needed (and the rectifier in the unlikely event one exists). Even then, unless you want a charging light or other new items only running when charging a simple relay to operate the interior advert light and the cab fan when the bus is is all that is needed.

If, of course, you do want some modern engine protection then you could install water level and/or temperature, oil level and/or pressure and start inhibit if the engine is already running. that would mean some extra engine and cab wiring.

Other issues that may arise is to ensure no electrical equipment has an earth return if you want to retain the insulated return system.

The gear control should continue to function as is although a fitter may have a thought on mechanical issues that are beyond my knowledge

If you let me know what your bus is like at the moment, the details of the new engine stopping, what modern items or new protection you want or if you would prefer the operation and the cab to look as original as possible I could produce a drawing or take a look for you if you prefer.



David Colin

PS for Iveco owners, Can anyone tell me how you stop your bus engine. Do you simply turn the modern switch to off or do you need to turn it fully left against the sping to stop the engine. Cummins only need to be turned to off, The Scania I have seen needed to be switched to stop.

My bus number (if any): RML2276, M1001, T806

I answered your question thinking you were planning an engine change so the reply was more about what you would or wouldn't need to do if you were changing your engine!

I have always assumed the new switching, charging and protection arrangement was at the engine change and not at the refurb stage. I will have a look at the refurb spec to see if it mentions if it needs doing or was already done but I imagine it must have been done at the engine change or they would have needed to do further mods during the refurbishment rewire. At the very least the stopping circuit would have been done and therefore the starting arrangement as it became a single switch. As the alternator was also changed the regulator etc would have been replaced with charging relays and presumably the warning lamp fitted. I also imagine the low water level system would have gone in at this time as well. I am not sure, but I thought the gear controls were also upgraded at this point. I don't remember it being a part of the rewire spec in which case the speedometer was presumably done as well. I am only surmising though and those involved may have more information.

David

My bus number (if any): RML2276, M1001, T806

David

You raised an interesting point about the start inhibit, if 2250 had it, then would it have been connected in the auto neutral control panel ( I can see no link with starting circuit ), my own one is an SCG type with its function removed. Looking at drawing CR301W a number of terminals remained unused in the panel, which had a reverse gear connection from the selector switch ( terminal 20 ,) and battery +C3 from the switch & fuse panel. Again with the changes in use from GreenLine coach to service bus, it operated in permanent semi auto first then perhaps semi /fully auto when a service bus.
I have no start inhibit, so that could be potentially dangerous when someone is working on the bus. Therefore as I have no reset function at the gear selector switch ( only neutral connected through terminal 19 from ep valves to facia switchboard ), it would be possible to utilise these terminals ( would require 2 core cable/soldered connections ) connected via a relay. Operation of start inhibit would be by pulling the reverse gear catch out and holding the gear selector lever in the reset position at the bottom of the gate, whilst operating the starter switch. The latter may also provide security against the vehicle being driven without permission.
There is no mention as far as I can see about the start inhibit function of RM's in the Maintenance Bulletin or Walker Manual which has the wiring diagrams of both CAV & SCG panels. Perhaps an ex LT person can confirm the start inhibit function of original RM's including RCL types.

Stopping the Iveco engine is by turning the ignition switch fully to the left, energising the stop solenoid, again on 2250 the wiring seems different from the refurb RML's with Iveco engine and a stop relay connected at the Engine Stop / Start Panel - Iveco, which I do not have on 2250, just the Lucas Start / Stop ignition switch & ign warning lamp. Neither is there a oil pressure warning lamp in the circuit as shown in the refurb buses wiring diagram. I think it is indicative of the many variations found in Routemasters, particularly refurbished or ones that have undergone extensive conversion like 2250 of which I hesitate to describe the quality.

My bus number (if any): RCL2250

Ed. To stop an original RM you just pulled the Aarons cable button located on the engine shield, To start it you pushed it in and hit the starter. I believe the aarons cable activated the engine stop control isolating switch. I have sent you a wiring diagram so you can see for yourself.

My bus number (if any): RTL 960, RMC 1458 and several RTs

Brian

Thanks for that, it was David who wanted to know how the stop control operated on the Iveco engined bus. I'll have a look at the diagram to see how it compares to the Walker 90/1 drawing.

My bus number (if any): RCL2250

hi all as ed says you need to hold the start stop switch against the spring till the engine dies on an iveco as if you don't it will continue to run. in answer to your question ed i'm pretty sure i'm right in saying that like rmc's the rcl's were semi from new and if yours has a control panel in it i'd suggest it was fitted prior to it becoming a bus on the 149 route.as for rm's and rml's in pre refurb condition i'm certain they do have an interlock to stop them being started in gesr i'll check on thursday as will be working on an rm with auto thats un moded. regards. tim.

My bus number (if any): rm2023 2097 rml2388

One of the guy's that did the conversion is still around, although it's going to take me a while to track down his details. He used to be based out of Putney garage which was one of the few places that seemed to like the Iveco's. He now runs a business servicing static diesels but will still help out with Iveco engines, I got him to give mine a look over after I accidentally ran the fuel tank to empty and dragged all the grot up into the fuel supply system.

I'll post back again tonight once I get back to my main computer.

My bus number (if any): RML2644

Tim

I have looked at both RM drawings Walker 90/1 & CR301W as well as the CAV/SCG panel wiring diagram out of curiosity to see how the interlock/start inhibit actually operated, but could not see a direct link with the starter circuit. The opinion seems to be via the control panel which makes sense, ( how did it operate within the panel? ), but as there are variations between the drawings it is not clear.
2250 has no start inhibit at the present time, but I assume as you have mentioned that it would have had originally. I would be interested to know about the start inhibit on pre refurb buses, as there seems to be no information in the maintenance bulletin referring to its operation.

I have the SCG panel in place but not connected except to the cables connecting the accelerator switch & reverse gear. There is no power feed to the unit, but when I get a chance I will look at it in more detail out of interest. The bus is in permanent semi auto gear control, which is how I prefer it anyway due to the terrain down here in Cornwall.

My bus number (if any): RCL2250

Hello,

I was browsing regarding RM545, wondering what might have happened to it and where it might be now, when I found your web site. I thank Jack Norie for his complimentary remarks, nearly a year ago now.

Having been apprenticed at AEC Ltd and having worked there in the Engineering Department several years earlier, it was I who, while working for DAF, designed and executed the installation of the DK1160 engine in RM545. This was at the behest of Wandle District in 1986/1987 and full London Transport specifications were the order of the day. The work was done at first at Battersea and later at Wandsworth. Turbocharged engines of that time were not prefered and a larger capacity, normally aspirated engine was considered better for stop/start operation. When he heard of the project, the legendary Colin Curtis came to see it and was most helpful with his comments. However, the project took about eight months and, by the time it was complete, de-regulation had taken place and other, cheaper installations using Cummins and Iveco engines were being explored.

When complete, we tested it thoroughly, with full instrumentation and a full load of sand bags along the number 11 route. We followed a vehicle in service and stopped and started accordingly. I also had the priviledge of driving it, supervised by an LT inspector, to North Weald rally later that year.

I was naturally sorry to hear that the DAF engine has since been removed, but it had remained, as you say, a 'one off' and therefore not ideal in a large fleet.

Kind regards,

Jon Glenny.

Tony's bus retains its DAF engine and is in regular use for Private Hires.

Hello Ray,

Thank you for your response. It was good to hear that the DAF engine is still in service after all.

It would be good to see it sometime, if possible.

Kind regards,

J.G.