Setting the distributer drive cog - and close to giving up!!

Post by **alzax3** » Sun Sep 21, 2008 8:05 pm

I hope somebody can clear up my confusion here! I've got a BMC workshop manual that states that the drive will be right when the slot is at 1 o'clock and two other manuals that state that it should be at 20 to 2. (In both cases they state the larger segment should be uppermost.) (this is a 1098 engine)

So which position is correct?

Post by **rayofleamington** » Sun Sep 21, 2008 10:17 pm

It has not got that many teeth, so there is limited scope to change it!
The difference between 1 and 2 o'clock is not that much. If you use 1 o'clock it just means that the dizzy will be more upright when the timing is set correctly.

I had to change one yesterday (it made a nice break from standing in the sun at the Gaydon rally) and there's not a lot to it - however don't follow the Haynes procedure to the letter!

The piston flange (can't remember which one) can foul the drive when you try to remove it, so have the engine at least 30 degrees away from TDC for removal and refitting.

When you remove the dizzy mounting flange from the engine you can remove the drive by fitting a bolt in the central hole and wiggling/pulling it out. The gear teeth are helical so allow the shaft to rotate when its coming out.

To get it aligned correctly can take trial and error as it rotates when it goes back in. Once it's in, then move the engine back to TDC to check alignment to the book spec.
Take a first guess/estimate and if it's close but not quite right, pull it out and move round 1 tooth at a time from there.

Post by **bmcecosse** » Sun Sep 21, 2008 10:55 pm

And don't drop it into the sump - although it's a lot more serious when that happens in a Mini! Doesn't matter a hoot where the drive cog is of course - provided you can get the dizzy in and timed correctly. Problems can arise when T piece for oil P gauge gets in the way!

Post by **alzax3** » Mon Sep 22, 2008 8:07 pm

I've added the 'close to giving up' bit because I seem to have hit a brick wall..... I'm not new to messing with engines - been doing it for 30 odd years. I've got this second-hand- but never-been-used/fitted ESM rebuilt 1098 engine. Great compression, the number 4 cylinder valves are rocking when the timing marks are lined up for number 1 cylinder - so I have to assume that the valve timing was set up as it should be. The drive cog is in place, the distributer is adusted so a bulb just goes out (ie points just about to open.) I've tried shifting it a long way advanced and retarded (in small increments), changed points/condensor/plugs/, two carbs, even a sniff of easy start and the best I can do is get spitting back through the carb. Never a hint of a proper fire. (other than the flames of spitting back, which doesn't count.

) Despite only using short bursts of the starter I've reached the point where it may have done more than it's happy with - has anybody got any suggestions, I don't want to go and buy another starter and still not have the engine sorted?

Post by **aupickup** » Mon Sep 22, 2008 8:13 pm

spark plugs ok, coil ok, leads ok, not much else, do all valves open and clase

Post by **alzax3** » Mon Sep 22, 2008 8:26 pm

Well again, I've got to assume so - it's got compression, so it must be drawing that in through the inlets - I guess if the exhausts weren't opening it wouldn't have a choice but to pressure back through the carb, and I'm sure it wouldn't run. I don't want to take the head off for the sake of it.......

Post by **aupickup** » Mon Sep 22, 2008 8:30 pm

hmm at a loss then

i take it the dizzy roter arm is turning and all ok

Post by **alzax3** » Mon Sep 22, 2008 8:37 pm

Yup, the rotor is turning, and it was the choice of about 5 distributers in terms of not being 'loose and sloppy'.... 'at a loss' is exactly how I'm feeling! (I just keep hoping I've missed something obvious!) I turned over the other spare engine I have here today, do discover it's got a very serious 'clunk/lock solid' which could well be a broken conrod so I really have to get this one running!

linearaudio · Post by **linearaudio** » Mon Sep 22, 2008 8:39 pm

When you say the bulb is just about to go out, is the other side to +12v? I ask as I usually run the test bulb across the points, ie to ground, so it would light when the points opened. Silly question probably, but when you're really scratching your head, you have to ask! Also(probably even more silly) you are assuming anti- clockwise rotation of the distributor? I remember struggling years back timing my first a series, till I realised it turns anti-clockwise. Somehow I'd got it fixed in my head it would turn the same way as the engine (from the front). Sorry if I've insulted your intelligence, but sounds like you've done all the obvious things!! Good luck.[/u]

Post by **alzax3** » Mon Sep 22, 2008 8:50 pm

I don't mind how much my inteligence is insulted if it gets the problem sorted! I've connected the bulb to the same coil terminal as goes to the distributer, and then to earth (it's a negative earth car) with the square of the shaft just about to move the heel as it turns anticlockwise (if I didn't know which way it went when I started, I've been fiddling with it for so long I do now!)

Post by **alex_holden** » Mon Sep 22, 2008 8:52 pm

I've only had kicking back when I accidentally connected the HT leads out of sequence (duh!).

Post by **alzax3** » Mon Sep 22, 2008 8:57 pm

And since I've worked on VW Beetles recently I could easily have done just that - but Morris's have the lovely cast - in firing order on the manifolds.......... I'm going to have a lie down and recover - hopefully somebody will come up with the magic answer while I'm asleep!

Post by **Shawn** » Mon Sep 22, 2008 9:45 pm

Are you positive you're at TDC on the compression stroke? Twice now I've wasted a day looking for other problems when in reality I was trying to set the timing at TDC on the exhaust stroke.

Post by **bmcecosse** » Mon Sep 22, 2008 11:21 pm

Firing order 1342 (anticlockwise round the dizzy) - but of course - #1 lead must be on the correct spark plug when that cylinder's valves are closed! So set it up and note where the rotor arm is pointing !

Post by **alzax3** » Tue Sep 23, 2008 8:24 pm

Well - finally got it firing, (by dint of removing the manifold, turning over and watching the flames come out of the inlet holes(!) then fiddling around until they were coming out of the exhausts.......But the starter motor really isn't going to play much longer, and is now so slow that It's not going to do the job. So I'll have to get a replacement for that before I can progress any further.

On a happier note, the clunk/sieze problem with my other spare engine is not a con-rod, it's the fact that the timing gears and chain are sat in a cardboard box rather than hiding away under the bolted down timing cover

- you just never know what you're getting when people throw in a load of spares with a purchase!!

Post by **rayofleamington** » Tue Sep 23, 2008 10:55 pm

If you've had the rocker cover off, then I hope you've checked that the valves are fully closing (i.e. the rocker has some slack - prefferably the right clearance)

Are you positive you're at TDC on the compression stroke? Twice now I've wasted a day looking for other problems when in reality I was trying to set the timing at TDC on the exhaust stroke.

From your description of TDC when #4 valves are rocking sounds right, however, I always add an idiots check (for my own benefit) to make sure #1 is on compression stroke.
Take the plug out of #1 and rotate the engine using the starting handle with a finger lightly over the plug hole. When it blows past your finger when approching TDC, then you've got the compression stroke. Continue to somewhere about 6 degrees before TDC, then 12v through a bulb to the points and set the dizzy until the points are just opening.
That's never failed to get an A-series started for me. Your problem would annoy the heck out of me if that didn't work!

Post by **alzax3** » Wed Sep 24, 2008 8:28 am

Thanks Ray, I've been through the 'annoyed as hell' past the 'I'm obviously not as mechanically adept as I thought' and even the 'cussed thing has been invaded by gremlins'

.............but things do look a little more positive now, just a pain not being able to prove the point because of the failing starter.

All the clearances that can be set have been - so there is .012 clearance on the rockers as I'm setting the timing.....The only other engine that has given me this much trouble was a rebuilt Standard 23c diesel on a MF35 and I beat that in the end, so I'm still hopeful!

Post by **bmcecosse** » Wed Sep 24, 2008 2:20 pm

Sure it needs a new starter - and not just charging up the battery ? The timing must have been miles out to get flames in the inlets - ! I thought you said you had set it up ?

Post by **alzax3** » Thu Sep 25, 2008 7:14 pm

Well after a fruitless half day when whatever I did I couldn't get more than a backfire wherever I put the distributor - even though there was a decent spark at the plugs and with them all out and earthed I could see them cycling (made easier by the slow starter motor!) I decided to try a different distributor. They seemed identical, so I set it up so I could do a straight swap. Static timed as I've been doing all along turned the key and instant ignition - set the choke out a bit and it started and ran!

So I have no idea what's wrong with the first distributor, I guess I'll dismantle it and see sometime, but after the three or four days it's wasted for me I won't be in a hurry to experiment! (And I can stop feeling completely incompetent!)

Post by **bmcecosse** » Thu Sep 25, 2008 10:42 pm

It may have been assembled 180 degrees round relative to the offset dog on the drive spindle. Thus the sparks would be 180 degrees out!