Hello. I have recently completed some heavy work on an AEC engine and whilst doing this I had the Simms pump sent off for reconditioning. Does anyone know the correct method for setting up the timing. I marked up TDC on engine and pump flywheel but want to be certain I get it right. There are several increment markers on the engine flywheel. Any help gratefully received. Adam.

My bus number (if any): RM1859 RM1990

You need to make sure the engine is coming upto TDC for number one not number six, with the rockers off look at the valves, number one should have both closed and number six exhaust (fifth valve from left on that head from memory) should be closing.
injection timing should be 14 degrees BTDC (double check but it is that if fitted with a DPA pump as just done a Regent V) as marked on flywheel. Line up with pointer affixed to bellhousing at about 7 oclock viwed from rear, the small lines are 2 degrees and the longer lines are every 10 degrees.
Once engine set to 14 degrees before topdead, line up mark on fuel pump drive wheel with its pointer or mark on pump body and fit to engine and couple up pump drive.
I'm sure there will be a couple of Roys along shortly wih more or improved info...

Mark

My bus number (if any): RM1414 sort of

What is the pump identification code please? something like SPE6A85S....... ?

More than one method which all achieve the same result. LT set everything on TDC no1, but you do need to have a mark on the pump flywheel known to be TDC and not INJ no1.

Sorry to say DPA timing is always different from inline.

You wait hours for a Roy and two come along together...as other Roy says, LT "usually" set everything to TDC so what Mark says is ok for a standard AEC.

So, lift the flywheel cover in the lower saloon. there should be a pointer fixed to the back of the engine block at the top of the flywheel. On the outer edge of the flywheel somewhere are a set of scribed marks, probably hidden under the rust. Carefully turn the flywheel until these marks can be seen.

These range from about 5 down to 0 TDC. The 0TDC needs to be in line with the mark on the pointer. This gives you top dead centre. Then go under the bonnet. On the pump drive should be a scribed line on the drive shaft where it comes out of the steering pump. Can't see the mark? Back inside and turn the flywheel a complete turn and then you should see it.

This should line up with a pointer on the steering pump. there will be a similar pointer on the fuel pump and as others have said, a scribed mark on the pump drive. Line this lot up and it should be ok. The adjustment screws are usually midway round the slots.

Tighten everything, make sure to top up the pump governor, fill the pump with engine oil, bleed the fuel through and with luck it should start. It will take a LOT of turning so make sure you have good batteries.

When the engine fires, it will be on one or two cylinders. Best slacken off the injector pipes at the injectors before you start turning the engine! It helps bleed the system quicker. The engine should run.

If it doesn't, the engine may have been set to time at 4 5/8th" before TDC. So you'll have to reset the pump coupling timing. If it shows no sign of firing, the chances are the whole lot is 180degrees out for some reason, in which case remove the pump coupling bolts, turn the pump coupling halt a turn, and refit the bolts. It has been known!

Any fine tuning can be done by loosening the coupling bolts and moving the coupling back or forward. the engine should have a nice crackly AEC sound; it should respond immediately to the throttle control and pick up immediately. If the engine is sluggish, the pump timing need to be advanced, bolts slackened and the coupling moved clockwise slightly, just a mm at a time. If it's too crackly, it needs retarding. Slacken the bolts and move the coupling anti-clockwise.

Once it runs to your satisfaction, make sure everything's tight, no fuel leaks, wash any excess fuel from the engine bay.

Topping up pump oil, remove the filler plug on the side cover and put half a cup of engine oil in the pump. Any surplus should run out of the overflow pipe. Remove the huge brass filler plug on the governor and put about a quarter cup of engine oil in there. Again, any surplus should run out of the overflow pipe at the back of the governor.

Make sure the engine stop control works! Also check for smoke once the engine has warmed up.
There is a way to check the timing scientifically, but I usually do it by ear and experience.

Edited to add remove the front wing, it makes the job a whole lot easier.

My bus number (if any): RML2532 Keeping Europe's Routemasters on the road.

Thank you very much to all of you! I shall be visiting the bus on Sunday, so I shall report back soon!

My bus number (if any): RM1859 RM1990

Hi Adam.

I have an origanal AEC service manual for 590 and 690's. It has all the all the set up details for all pump variants. Give me a call to remind me before we meet up this weekend and I will bring it down and you can borrow it. It will take you through what you need to do step by step. Cheers Mitch

My bus number (if any): RMC1462

The AEC manuals are naturally very specific about pump timing. Care needs to be taken that the correct imformation is used. AEC engines use a variety of pumps and timings. Which is no doubt the reason for LT deciding that they would mark everything for TDC. In this way their many only semi-skilled fitters would be unable to get it wrong.
In particular, the individual make and model of pump fitted and the engine onto which it is going determine whether, for instance: 14 21 23 24 25 27 or 28 etc degrees is correct. The type and size of flywheel also effects this too. One needs to read the pump code and know the diameter of the flywheel and whether the flywheel is marked in degrees, inches or hopefully injection no 1.

To convert the diameter to the circumference as follows: Circumference = pi times diameter. pi = 3.14 or 22/7.
dividing the answer by 360 will give how many units of measurement = one degree.

The probable diameter of an RM flywheel is 19.8 inches.

There is a second engine position pointer attached to the rear of the power steering pump.

I have a Simms pump with a missing id plate which is one reason fo rasking for the details please.

To answer Mitch, the AEC book is not much use when setting an LT engine.

My bus number (if any): RML2532 Keeping Europe's Routemasters on the road.

Hello everyone. With much adjustment and fine tuning, I finally obtained a satisfactory setting by using both TDC markers. A lot was done by ear and now the engine seems very responsive with very little smoke t all. Thank you all very much.

You're welcome.

The ears have it!

My bus number (if any): RML2532 Keeping Europe's Routemasters on the road.