Basic timing questions from a complete novice.

eadmr04

eadmr04

Member
Just starting to try and get my head around basic timing on my "68 P6b. Here is what I know.

I bought the car about 10 years ago off of a well known previous member John Glinn who had a very good knowledge of most things P6 wise. I know that he set the timing at TDC (zero degrees) rather than the normal 6 degrees BTDC to allow for modern day fuels etc. I run the car on super unleaded as much as possible and also add Castrol valvemaster and octane booster. I'm thinking of changing over to electronic ignition and what to get all my facts straight before I do.

I have being doing a bit of reading and I think I've read that when the timing pointer is at firing point it should be firing on plug one and the rotor arm should be pointing at the lead going to plug number 1. Is this correct? I have managed to use a socket on the crank pulley bolt to turn it to line TDC with the pointer but when I do this I remove the distributor cap and the rotor arm is pointing at the lead which goes to the 3rd plug back on the left hand side looking from the front of the car, I think this is plug number 6?

Can anyone shed any light on this and if I'm being a complete idiot can anyone give me a bit of a basic guide so I can start checking things out?

Many thanks.
 
Cheers Harvey......once again. Does the timing setting I'm running sound sensible or should I head a bit more towards the 6 degrees BTDC?
 
I'd start off at 6BTDC and then if it pinks at that retard it a bit at a time until the pinking stops.
 
Maybe it´s worth to check, if your pointer TDC mark really is TDC. Take plus out of cyl 1, put a straw in, turn the engine and compare TDC pointer mark with piston on top position. You might need more than one turn to get familiar with your engine...
I do not know the qualities in the UK, but I read Premium is 95 oct and Super is 98 oct. If you use Super, why the octane booster ?
 
I can remember my dad resetting his
10/5/1 at TDC when 5 star fuel stopped. Which I think rover dealers used to do as well. (I think it knocked off 6 BHP! )
He noticed a lack of sparkle it used to have.
Some engines require experimenting on timing settings due to wear / maintenance differences.
I use Harvey's method once running it on 98 Ron fuel with no problems.
Have even had one engine timed to 8 BTDC with no pinking or overheating.
Clive.
 
mtb_tuli said:
Maybe it´s worth to check, if your pointer TDC mark really is TDC. Take plus out of cyl 1, put a straw in, turn the engine and compare TDC pointer mark with piston on top position. You might need more than one turn to get familiar with your engine...
I do not know the qualities in the UK, but I read Premium is 95 oct and Super is 98 oct. If you use Super, why the octane booster ?
Click to expand...
So would I just be looking for where the piston is at it's upmost and the straw is pushed it's furthest out?
 
You wrote, you are a novice, and that´s where everyone started. Harvey gave you the firing order, so it´s a learing course i.e. To check if your rotor arm moves clockwise (you do not have to move it, just start with rotor arm on cyl 1) to the next position Harvey informed (follow the lead and you will arrive at the right cylinder). As your car runs "good", nothing will be wrong, it simply helps understanding. The check of the TDC pointer with comparing if the piston here is really in his upper position will give you some safety because you start now on this position with all further work and then it should be ok. The pointer is fixed with two bolts to vary its position. Normally none has changed it, but who knows.
To put a straw in (take a long one !!) is a simple method and it does not damage anything. It should be a long one, not that it falls in when the piston is down :confused:. When you are not sure, wrap tape around at the outer end, which is thicker than the plug opening. Be careful with tightening spark plugs, less is better, you have an aluminium head. Don´t take a ratchet, use a simple T-bone plug socket.
 
mtb_tuli said:
You wrote, you are a novice, and that´s where everyone started. Harvey gave you the firing order, so it´s a learing course i.e. To check if your rotor arm moves clockwise (you do not have to move it, just start with rotor arm on cyl 1) to the next position Harvey informed (follow the lead and you will arrive at the right cylinder). As your car runs "good", nothing will be wrong, it simply helps understanding. The check of the TDC pointer with comparing if the piston here is really in his upper position will give you some safety because you start now on this position with all further work and then it should be ok. The pointer is fixed with two bolts to vary its position. Normally none has changed it, but who knows.
To put a straw in (take a long one !!) is a simple method and it does not damage anything. It should be a long one, not that it falls in when the piston is down :confused:. When you are not sure, wrap tape around at the outer end, which is thicker than the plug opening. Be careful with tightening spark plugs, less is better, you have an aluminium head. Don´t take a ratchet, use a simple T-bone plug socket.
Click to expand...
Thanks MTB :)
 
Putting a straw into the cylinder is really not very accurate, and the old way of judging when the piston is at the top by looking down the spark plug hole (or watching the valves rock) and moving the engine about is even worse because of the time the piston 'dwells' at the top of its stroke.

When I first tested my engine it was 8° out :eek:, so I adjusted it to the limit on the pointer and it was still out.

I made up one of these from an old spark plug and bolt. Loctited the nut on then ground the nut down on a bench grinder until it fitted into the spark plug hole. I then rounded the tip of the bolt off to avoid scratching the pistons.


IMPORTANT!! Ensure that number one cylinder is nowhere near TDC and insert the piston stop. Remove all of the other spark plugs, then turn the engine slowly by hand until it stops - mine was 17 degrees ATDC


Then turn it the other way until it stops - 15 degrees BTDC



TDC is exactly half way between the two, i.e. the pointer is at 1° ATDC when the engine is at TDC.

So I took the pointer off, cleaned it and the area where it sat, filed a bit off and hit it with a hammer, now it sits exactly on TDC when at TDC, so we know it's accurate.

A bit of a long winded way of doing things but very accurate.

Richard
 
quattro said:
Putting a straw into the cylinder is really not very accurate, and the old way of judging when the piston is at the top by looking down the spark plug hole (or watching the valves rock) and moving the engine about is even worse because of the time the piston 'dwells' at the top of its stroke.

When I first tested my engine it was 8° out :eek:, so I adjusted it to the limit on the pointer and it was still out.

I made up one of these from an old spark plug and bolt. Loctited the nut on then ground the nut down on a bench grinder until it fitted into the spark plug hole. I then rounded the tip of the bolt off to avoid scratching the pistons.


IMPORTANT!! Ensure that number one cylinder is nowhere near TDC and insert the piston stop. Remove all of the other spark plugs, then turn the engine slowly by hand until it stops - mine was 17 degrees ATDC


Then turn it the other way until it stops - 15 degrees BTDC



TDC is exactly half way between the two, i.e. the pointer is at 1° ATDC when the engine is at TDC.

So I took the pointer off, cleaned it and the area where it sat, filed a bit off and hit it with a hammer, now it sits exactly on TDC when at TDC, so we know it's accurate.

A bit of a long winded way of doing things but very accurate.

Richard
Click to expand...

Cheers Richard, coincidently enough I have a piston stop already made which I use when setting the timing on my Lambretta so understand the principle now. The trouble with the Rover is trying to get at everything with the limited space :confused:. Think I'll have a good go at this at the weekend and see if I can get everything marked up. I can see the writing and markings on the pulley but they are not very clear like yours shown. Just a thought, would it work to paint the whole section with something like tippex and then rub the surface down to leave the paint in the recesses?
 
I cleaned it with a small wire brush (careful with the rad) then painted it with tippex, and wiped it off before it dried. Worked a treat :)
 
Right, just getting myself geared up to ready to have a little play tomorrow and had just found that out of the 4 spark plug sockets I've got, none of them fit inside the cylinder heads!!! I can get one of them in on one of the plug holes but that's it. Is there a specific plug socket required?
 
High quality makes like snap-on sell thin wall plug sockets, I've got a selection of cheapies I've had turned down on a lathe over the years.
 
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