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Timing question


MiketheBike

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I have always thought that to adjust timing by ear, with the engine idling, you advance the timing until it just starts missing, then back it off a bit?

 

On a ferret, the two bolts that hold the distributor down, are through two slots in the mounting bracket, with a limited amount of mevement, about 15 degrees?

If I advance the timing as far as it will go (rotating the dist anti-clockwise) it never gets to that point where the engine starts to miss or slow down.

 

Could it be possible that the oil pump has been replaced, and has not been put back in correctly? How far out would it be, if the skew gear was 1 tooth out?

Do you think I could move all the leads around one place and then fully retard the dist, just to see if that advances the timing enough?

 

I could just get cylinder one to TDC and check the distibutor driving slot on the top of the distributor drive shaft, but my starting handle appears to be the wrong one.

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I read recently that the B-series RR engines have a static timing of 0 to 2 degrees After TDC to facilitate hand starting (this prevents kick-back through the starting handle) up to about 300rpm when the timing goes back to "normal". Since the engine idles at 550 rpm min, you can't set this at idle. Maybe best to start by setting static timing to a gnat's after TDC?

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The only way to time a B series Rolls-Royce is STATIC between 1 to 2 degrees AFTER TDC. Any other way will result is poor performance, hard starting when hot and burnt valves. Another point to remember on the B80 / 81’s is to synchronise the two set of points to fire exactly at 45 degree intervals.

Sorry to sound a bit harsh but it really frustrates me the amount of people who slag off the Rolls-Royce B series engines especially the 8 cylinders, and most of the time its down to incorrect setting up. The B series is quite forgiving but when set up right the difference is quite amazing.

Timing an engine by ear is ok for a get you home, like setting your points with a bit of fag packet.

Come on lads give your engine a bit of respect and set it up properly, it deserves it.

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Hi Grumpy...reality check :)

 

I guess all those things I have been told when I was younger are being dashed...I thought that with older engines static timing was a bit hit or miss due to wear, but I can see your point...doing it by ear will almost guarantee hit or miss...

So I set the timing mark to 1 or 2 degrees ATDC, and the points should be just opening?

 

Anyhow...I checked the position of the slot at the top of the distributor drive shaft with the timing mark at TDC and it appears to be in the correct position (parallel to engine), so the oil pump appears to inserted OK.

 

One set of points did seem kinda burnt (the ones NOT directly attached to the capacitor) . I checked the continuity between the posts on the two sets of points and there is continuity. I will keep playing.

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The only way to time a B series Rolls-Royce is STATIC between 1 to 2 degrees AFTER TDC. Any other way will result is poor performance, hard starting when hot and burnt valves. Another point to remember on the B80 / 81’s is to synchronise the two set of points to fire exactly at 45 degree intervals.

Sorry to sound a bit harsh but it really frustrates me the amount of people who slag off the Rolls-Royce B series engines especially the 8 cylinders, and most of the time its down to incorrect setting up. The B series is quite forgiving but when set up right the difference is quite amazing.

Timing an engine by ear is ok for a get you home, like setting your points with a bit of fag packet.

Come on lads give your engine a bit of respect and set it up properly, it deserves it.

 

Agreed. Of course I've only used the by ear method when no other equipment is available.

As you say twin points makes for a decent dwell angle, time for capacitor to give a decent spark if a else is O.K. Better than the standard Rover V8 set-up anyway.

 

Probably worth while getting a proper tune up done in fuel savings alone. If not at least do what I have and invest in a multi meter with dwell angle and a xenon timing light.

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I cannot stress the importance of synchronisation of the points; it can only really be done with the dizzy out. You will need a protractor mounted on the shaft and a pointer.

 

I use a normal plastic half round protractor with a hole drilled in the centre. You then take out the screw that holds the cam to the shaft and use a slightly longer screw to fix the protractor to the top of the cam, one off the dizzy cap is just the right length. Make a pointer from a bit of welding wire ground to a point and fix it to the side of the dizzy enabling you to read the protractor.

 

The procedure I normally use is:

 

 

  • Take the dizzy out and mount it in a vice.
  • Clean, dress & gap both sets of points (try to get the points gapped as equal as possible)
  • Mount the plastic protractor on the spindle & fix the pointer as above
  • Rotate the shaft in the correct direction (clockwise) until the first set of points just open. (use a multimeter or battery & bulb)
  • Zero the protractor & pointer
  • Continue to rotate the shaft until the second set of points just open
  • The protractor should be reading exactly 45 degrees for a 8 cylinder engine and 60 degrees for a six cylinder engine
  • If not, adjust the sliding set of points in the right direction until you get exactly 45 or 60 degrees between the opening of the two sets of points.
  • Finally seal the set screws securing the sliding points with paint.
  • Re-fit dizzy and adjust timing to between 1 to 2 degrees ATDC

One point to remember, there are two types of points fitted, one with a wide shoe that runs on the cam and one with a narrow shoe. Either will work but you cannot mix a narrow shoe with a wide shoe as there is not enough adjustment in the sliding points to achieve the 45 or 60 degrees between firing. If you are stuck you can file a wide shoe down with a needle file.

 

If you want to do a quick check with the dizzy still on the engine you can do the following to see if the point’s synchronisation is even close (six cylinder only)

 

 

  • Clean both sets of points and ensure both are gapped equal and correct.
  • Turn the engine with the plugs out until the fixed set of points are just opening on number one firing stroke
  • Note the timing mark on the flywheel
  • Turn the engine through one complete revolution until the sliding set of points are just opening number 6 firing.
  • The timing mark should now be in exactly the same position as with number one firing; if not the point synchronisation needs to be adjusted as above.

Hope the above helps but it isn’t a five minute job, and if checking with the dizzy still on the engine it’s a two man job, which is why I usually find it quicker to take the dizzy out.

Edited by Grumpy
Because my brain is old
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Guest catweazle (Banned Member)

i agree with all thats said,but have found in reality after the initial set up rd testing is the only way to get the best performance,the timing needs trying in different places till the best feel is found.I use this method on all the rover products and the b series engines.I got fed up with customers moaning it went worse after a service than before.the main reason being it was set to manufactures settings.a lot has changed since then especially the petrol.re checking after setting is sometimes surprising and you wonder should it be left like that.What works on one engine may be not what the next one likes.We are dealing with a variety of old engines and like old people they like to be different.I normally keep advancing the spark till the engine pings underload

then back off till it just goes away.I havnt found any damage done to any of the vehicles since 1974.:-D

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,but have found in reality after the initial set up rd testing is the only way to get the best performance,the timing needs trying in different places till the best feel is found.I use this method on all the rover products and the b series engines.

 

We are dealing with a variety of old engines and like old people they like to be different.I normally keep advancing the spark till the engine pings underload then back off till it just goes away.I havnt found any damage done to any of the vehicles since 1974.:-D

 

 

I agree with all CW says on this subject. What is forgotten is that a lot of the manuals and tech info you are reading are basically out of date when used against the formula of petrol as it is today. To start with RR B range, there is a very limited adjustment on the distributor, due to the slots. RR never really updated their tech info, not the engine, from when they first built it. The point about timing being at a point where it will not kick back on a handle, would seem like a compromise point.......how often do we hand crank an engine now, unless it is of a prewar vintage and is a neccessity.

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I think the point to remember here is it’s always best to start off with the factory settings, ignition first and then fuel. Then if you know what you are doing you can have a play and get the best out of your engine like CW says, but you must start from a base point otherwise you will just be chasing your tail.

 

The factory settings are usually safe in regards to detonation (pinking) which is where the damage begins, Richard / CW, you have considerable experience and know what you are listening for when trying to get the best out of an engine, lets face it its hard to hear a B81 pinking in a Stolly going full chat at the best of times.

 

From personal experience I have always found the B series engines run best at around 1 Degree ATDC static especially when starting from hot, but this is probably due to the long stroke and combustion chamber shape rather than a requirement to hand crank / start.

 

Today’s petrol formula has changed but the majority of changes cancel themselves out, for example petrol today burns slower but the octane rating is much higher than the B series was designed for. The biggest problem is getting it into the combustion chamber with a carburettor as opposed to fuel injectors but that’s a different subject.

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Guest catweazle (Banned Member)

Grumpy i did say i agreed with your initial set up procedure mate and i think your point about the twin set up is very well illustrated,and admirally explained by yourself.:-D

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I cannot stress the importance of synchronisation of the points; it can only really be done with the dizzy out. You will need a protractor mounted on the shaft and a pointer.

 

I use a normal plastic half round protractor with a hole drilled in the centre. You then take out the screw that holds the cam to the shaft and use a slightly longer screw to fix the protractor to the top of the cam, one off the dizzy cap is just the right length. Make a pointer from a bit of welding wire ground to a point and fix it to the side of the dizzy enabling you to read the protractor.

 

The procedure I normally use is:

 

 

  • Take the dizzy out and mount it in a vice.

  • Clean, dress & gap both sets of points (try to get the points gapped as equal as possible)

  • Mount the plastic protractor on the spindle & fix the pointer as above

  • Rotate the shaft in the correct direction (clockwise) until the first set of points just open. (use a multimeter or battery & bulb)

  • Zero the protractor & pointer

  • Continue to rotate the shaft until the second set of points just open

  • The protractor should be reading exactly 45 degrees for a 8 cylinder engine and 60 degrees for a six cylinder engine

  • If not, adjust the sliding set of points in the right direction until you get exactly 45 or 60 degrees between the opening of the two sets of points.

  • Finally seal the set screws securing the sliding points with paint.

  • Re-fit dizzy and adjust timing to between 1 to 2 degrees ATDC

 

One point to remember, there are two types of points fitted, one with a wide shoe that runs on the cam and one with a narrow shoe. Either will work but you cannot mix a narrow shoe with a wide shoe as there is not enough adjustment in the sliding points to achieve the 45 or 60 degrees between firing. If you are stuck you can file a wide shoe down with a needle file.

 

If you want to do a quick check with the dizzy still on the engine you can do the following to see if the point’s synchronisation is even close (six cylinder only)

 

 

  • Clean both sets of points and ensure both are gapped equal and correct.

  • Turn the engine with the plugs out until the fixed set of points are just opening on number one firing stroke

  • Note the timing mark on the flywheel

  • Turn the engine through one complete revolution until the sliding set of points are just opening number 6 firing.

  • The timing mark should now be in exactly the same position as with number one firing; if not the point synchronisation needs to be adjusted as above.

 

Hope the above helps but it isn’t a five minute job, and if checking with the dizzy still on the engine it’s a two man job, which is why I usually find it quicker to take the dizzy out.

Super Post, one to keep if you have a B series engine!

 

Thanks Grumpy.

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