BMC 2.2 Injection Timing

[Quattrodave]

Evening all,

 

Reading the manual on page 'General data 5' it says the injection timing for the DPA pump should be 26 degrees Before TDC. 

Problem is I can't find any reference to the timing marks, I would assume they're on the back of the flywheel. 

Going through the manual and photos I have of the engine (cos we can't go out at the mo) I can't seem to find a likely window for the timing marks.

Does anyone know where I should be looking?

 

Thanks

 

Dave.

[Tony Brooks]

On the official Tempest/Newage marinisation )1970s) there was a little lozenge shaped plate on top of the flywheel housing. If you removed this the marks were on the on the periphery of the extra thick marine flywheel.

 

Can't comment on other marinisations that may or may not fit the heavier marine flywheel.

[Quattrodave]

13 minutes ago, Tony Brooks said:

On the official Tempest/Newage marinisation )1970s) there was a little lozenge shaped plate on top of the flywheel housing. If you removed this the marks were on the on the periphery of the extra thick marine flywheel.

 

Can't comment on other marinisations that may or may not fit the heavier marine flywheel.

Thank you.  I didn't realise there was a heavier marine flywheel ? makes sence tho, hopefully I have them...

When you say 'on top of the flywheel housing' do you remember if it was directly on top by the cylinder head or off center to one side or the other?

[Tony Brooks]

17 minutes ago, Quattrodave said:

Thank you.  I didn't realise there was a heavier marine flywheel ? makes sence tho, hopefully I have them...

When you say 'on top of the flywheel housing' do you remember if it was directly on top by the cylinder head or off center to one side or the other?

 

The flywheel housing that is between the engine and gearbox. On a car it would be called the bell housing. a sort of drum shaped cast iron thing maybe 3 to 4 inches thick. The little trap door was right on the top dead in the centre.

 

Can you post a photo of the back of the engine.

 

Boats don't have a hefty clutch assembly bolted to the flywheel and we also expect then to delver power to the prop at idle. The heavier flywheel or bulk ring in the case of the 1.5s helps keep idle in gear smooth.

[Quattrodave]

24 minutes ago, Tony Brooks said:

The little trap door was right on the top dead in the centre.

 

Can you post a photo of the back of the engine.

 

The heavier flywheel or bulk ring in the case of the 1.5s helps keep idle in gear smooth.

Perfect thanks.  I havent got a photo of that area of the engine, when i'm allowed there again i'll get one.

 

Yes, i did a couple of vehicle race engines a few years ago where, amongst other things, lightened the flywheels.  This had the oposite effect, it imporoved acceleration but made the idle lumpy, saying that they were designed to live between 6000 & 8000 rpm so we didnt care about idle ?

Edited April 3, 2020 by Quattrodave

[Bee]

Have I imagined it or are there timing marks on the crankshaft pulley?

[Tony Brooks]

36 minutes ago, Bee said:

Have I imagined it or are there timing marks on the crankshaft pulley?

I don't recall and on the 2.2s we had but you may be correct, it was over 40 years ago.

[RLWP]

Our distressed 2.2 has no flywheel, so that's no help...

[Tony Brooks]

 

 

Here is an image of the Newage version. You can see the lozenged shaped cover above the blue Newage label.

 

I think this one has a TMP gearbox, I am sure the BMC B type box had the same flywheel housing as well as the ones we fitted PRMs to.

 

 

However this one that claims to be a 2.2 seems to have no cover on top of the housing but does have  the hole in the side closest to us.

 

The marks are behind the starter ring gear.  I can't remember if the datum line to line up the timing marks was a line on the flywheel housing or another plate that is under the cover that has a pointer formed in it. I have a feeling at least some were the latter.

 

If the second image really is a 2.2 then it seems the flywheel timing marks must be in a different position so nowadays its possible flywheels might have been changed over.

Edited April 4, 2020 by Tony Brooks

[Quattrodave]

Ah, a picture speaks a thousand words! But now i'm not very hopeful for mine...

Edited April 4, 2020 by Quattrodave

[Bee]

The one I had was a 2.5 and was an ex black cab motor with an automatic gearbox so a fluid flywheel, I replaced it with a conventional flywheel and the flywheel housing was different too, can't remember if I replaced that. I think that had timing marks on the front pulley, Just saying to illustrate the strange differences between engines if you don't know the history.  It also had three pistons of one size and a fourth of a different size, it was a terrible thing but it ran for ages.

Edited April 4, 2020 by Bee

[Tony Brooks]

I have a dim image of a cast front pulley with a small hole drilled through the back face of the belt groove and the hole was a timing mark I am not sure if this was on  a 2.2 or even a boat engine though.

 

Also now the grey matter is unfogging a little I seem to recall a set of timing marks cast into the timing cover just in front of the injector pump, a set of three lines, one long. If I am correct (absolutely no guarantee on that) then that hole probably lines up with the marks so Bee may well be correct.

 

Back to Google images I think.

 

can't find a decent photo but those cast in marks can not be where I said they were. They might be on the cover at 12 o'clock just above the front pulley. Maybe @RLWP will have a look at his bitsa.

Edited April 4, 2020 by Tony Brooks

[Quattrodave]

I've been poking through the manual again, huge shot in the dark here does anyone have "BMC Timing Gauge 18G 698" that i may be able to borrow?

I'm guessing not but worth asking.  Jumping back, page 103 of the (PDF) manual talks about a timing pin @ 28 Degrees BTDC

 

 

What i'm thinking is if i can find  28 degrees BTDC, I can then mark the flywheel with a pointer & some white paint / tipex.

Once i have these visual marks i can use my diesel pulse sensor and advance strobe timing light to set the pump timing.

Seeing as the marks will be 28D BTDC the timing light will see this as TDC, so if i dial in +2D to the timing light it should allow me to set the exact moment of injection to 26 Degrees BTDC...

 

This all relies on 1. I can actually find the pulse sensor, last time i used it was probably 15 years ago and 2. the pulse sensor actually still works...

 

Does anyone see any flaws in my thinking.  I do realise that i may be over thinking this a little but i'm really board and my mind keeps wandering back to it.

Edited April 13, 2020 by Quattrodave
typo

[Tony Brooks]

Seems fine to me  as long as you actually have that timing pin hole in the back plate plus the corresponding hole in the flywheel. If you have the marine flywheel I fear the hole may not be there.

 

As far as the timing gauge is concerned as long as you have not messed with the timing chain ans as long as the chain wear is minimal I doubt you will need the gauge unless someone has moved the pointer.

 

I think Churchill  also made an adjustable gauge that you could alter to suit a whole range of engines using the DPA pumps.

[Quattrodave]

1 minute ago, Tony Brooks said:

Seems fine to me  as long as you actually have that timing pin hole in the back plate plus the corresponding hole in the flywheel. If you have the marine flywheel I fear the hole may not be there.

Good point, well presented ?

 

2 minutes ago, Tony Brooks said:

As far as the timing gauge is concerned as long as you have not messed with the timing chain ans as long as the chain wear is minimal I doubt you will need the gauge unless someone has moved the pointer.

I was very careful with the chain and it looked in pretty good condition TBH i did wonder how critical the timing actually was on these engines...

3 minutes ago, Tony Brooks said:

I think Churchill  also made an adjustable gauge that you could alter to suit a whole range of engines using the DPA pumps.

Interesting, you dont have any further info on this do you?  Doing some googeling now....

 

 

[Tony Brooks]

2 minutes ago, Quattrodave said:

Good point, well presented ?

 

I was very careful with the chain and it looked in pretty good condition TBH i did wonder how critical the timing actually was on these engines...

Interesting, you dont have any further info on this do you?  Doing some googeling now....

 

 

 

No, but there is an illustration on the British Bus group item that comes high up on Google.

 

I suspect that if you line the pump up to that pointer and run the engine you could then twist the pump (with difficulty) to get it running better and minimise smoke.

Edited April 13, 2020 by Tony Brooks

[Quattrodave]

1 minute ago, Tony Brooks said:

 

No, but there is an illustration on the British Bus group item that comes high up on Google.

Got it, MS.67B

[Tony Brooks]

Just now, Quattrodave said:

Got it, MS.67B

Bet that is a Leyland number

[Tony Brooks]

This may be a complete bum steer but if you can set the engine to 28degrees BTDC (or whatever) then there may be marks inside the pump that will allow you to twist the body to the correct position. I am sure you have a mechanical DPA pump a sper the snippet from the manual you showed and I can see no reason mechanical DPA pumps would differ between applications. I know Perkins used the internal marks on the 4-10x range but that's a hydraulic pump BUT this link may give you a clue about how to use the internal marks on your pump. I is not for your engine but is for your family of pumps.

 

http://www.classicmachinery.net/forum/viewtopic.php?t=12496