IGNITION TIMING AND SOLEX 30 FAI ADJUSTMENTS

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digcot65
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IGNITION TIMING AND SOLEX 30 FAI ADJUSTMENTS

Post by digcot65 » Wed Apr 20, 2022 3:36 pm

Im helping a friend,with his 1947 Rover 12 HP I want to check the ignition timing and also set up the carb I don`t think either have been checked for quite a few years Len

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luli
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Re: IGNITION TIMING AND SOLEX 30 FAI ADJUSTMENTS

Post by luli » Thu Apr 21, 2022 12:48 pm

See here the official Rover instructions:
http://www.rover-forum.thersr.co.uk/vie ... 032#p11766
I am also adding the official ignition instructions:
THE ROVER COMPANY LIMITED A. 466
Sheet 1 of 4 sheets.
SERVICE BULLETIN.
SUBJECT : valve and ignition timing.

MODELS : All models 1934-47

Engines used on the above models fall into two groups for tappet clearance, two groups for valve timing and three groups for ignition timing as follows :-
Tappet Clearance.

Group 1. 10, 12 & 14 h.p. 1934-37 Group 11. 10 & 12 h.p. 1937-47
16 & 20 h.p. 1937. 14 & 20 h.p. 1938-47

Valve Timing.

Group 1. 10 & 12 h.p. 1934-47 Group 11. 14 hp 1934-38
14 h.p. 1939-47
16 h.p. 1937-47
20 h.p, 1937-40
Ignition Timing.
Group 1. 10 & 12 h.p. 1934-36 Group 11. 14 h.p. 1934-38
Group 111. 10, 12 and 14 h.p. 1939-47
16 h.p. 1937-47
20 h.p. 1937-40
Before timing is commenced, reference should first be made to Part 1 Flywheel Marking, after which the group concerned for the subsequent operation should be ascertained and attention transferred to the correspondence section of the text.

PART 1 FLYWHEEL MARKING (ALL MODELS).

The markings on the flywheel .are as follows:-

The mark T.D.C. indicates when No. l and No.4 (4 Cylinder engines) or No (6 Cylinder engines) pistons are at the top of their stroke.

The mark E.P. when brought opposite the pointer on the clutch housing indicates that the No.l. EXHAUST VALVE should be at the peak of its lift (fully open).

The letters F.A.4 (4 Cylinder engines) or F.A.6 (6 Cylinder engines) indicate-the FIRING POINT. When the mark accompanying these letters is brought opposite the pointer on the clutch housing, the distributor points should just commence to seperate.

As flywheels, for 4 cylinder and. 6 cylinder models are dimensionally identical, some may be found bearing both F.A.4 and F.A.6 marks; Care should be taken to use the correct mark when timing.

NOTE: In some instances the letter S.F. Adv. have been used instead of F.A.

Firining Order.
All 4 Cylinder models 1,2,4,3.
All 6 Cylinder models 1,5,3,6,2,4,

PART 11 TAPPET CLERANCE.

The correct tappet clearance on both inlet and exhaust with the engine HOT are :-

GROUP 1, Tappet clearance .005”.
GROUP 11, Tappet clearance .010”.

NOTE : The later type camshaft as used in GROUP 11 may have been fitted to models in GROUP 1, thus necessitating .010" tappet clearance on engines irrespective of their year of manufacture. It is essential, therefore, when cabling with GROUP 1 models, that reference bo made to the instruction plate on the rocker cover for details of the correct clearance.
It cannot be emphasized too strongly that the clearance must be correct and the engine must be hot. If anything less than the indicated clearance is used, a fall in power output will follow and any greater clearance will mean noisy tappets.

PART 111 VALVE TIMING.

A. TIMING CHAIN OIL SPRINKLER.

All models 1934-46

It is important that the timing wheels and chain obtain adequate lubrication from the oil sprinkler, This point should be checked at all times when the front cover is removed, particularly when new wheels or chain are to be fitted. Whenever there is any evidence that the oil flow is insufficient a new sprinkler unit should always be fitted, or the life of the new parts is likely to be considerably shortened.

B. RE-TIMING THE ENGINE.

If the chain should have boon removed the procedure to re-time the engine is as follows:-

GROUP 1. The mark E.P. is 108 before T.D.C. (29 Flywheel teeth).

1. Set tappets as instructed in Part 11.
2. Rotate camshaft in running direction until No.l. EXHAUST VALVE is fully open.
To use of a dial indicator is the only reliable method of determining this point. It should be mounted on an adjacent rocker shaft stud by means of a small right-angle bracket and with its aid the possibility of an error in determining the exhaust peak is eliminated. It is possible to do the job correctly without a dial indicator, but much time is wasted and the possibilities of an error very much magnified.
3 . Rotate engine until E.P. mark on flywheel is in line with the pointer in the clutch housing aperture.
4. Fit timing chain.

The camshaft chain wheel is fitted with several keyways, that if the timing will not come correct in the first position, alternatives are provided.

GROUP 111. The mark E.P. is 108° before T,D.C. (29 flywheel teeth).

1. Set tappets as instruetructed in Part 11.
2. Assemble timing chain and chain wheels in any position, using one set pin only.
3. Adjust timing chain by slackening the dynamo bolts and pulling the dynamo away from the engine.
4. Rotate engine in running direction until No.l. EXHAUST VALVE is fully open.
The use of a dial indicator is the only reliable method of determining this point. It should be mounted on an adjacent rocker shaft stud by means of a small right-angle bracket and with its aid all possibility of an error in determining the exhaust peak is eliminated. It is possible to do the job correctly without a dial indicator, but much time is wasted and the possibilities of an error very much magnified.

5. Remove set pin from camshaft wheel.
6. Rotate engine until the E.P. mark on flywheel is in lino with the pointer in the clutch housing aperture.
7. Three of the holes in the camshaft wheel should now correspond with in the camshaft iteslf. If they do not, lift off the wheel and rotate one tooth in either direction, taking care that nothing else moves also. In one or other of those positions the bolts will register.
8. Fit bolts, check timing again and if accurate, fit new locking wire through the holes provided.

PART IV IGNITIOIN TIMING.

If the distributor has boon removed for any reason, it becomes necessary to retime as follows:-

GROUP 1. The F.A.4 mark 11° before T.D.C. ( 3 flywheel teeth).
1. Rotate the engine until the F.A.4 mark on the flywheel is in line with the pointer in the clutch housing aperture with both valves on No.l. Cylinder closed.
2. The rotor arm of the distributer should now correspond with No.l Cylinder H.T. lead terminal. Should the engine have been stripped and re-assembled the rotor may be up to 180 away from the No.l. Cylinder position; in such cases remove the oil pump and rotate the pump and distributor driving shaft in the required direction until the correct position is obtained. The oil pump is inside the sump, which should not, therefore, be fitted until the timing is definitely correct.
3. Set the ignition lever en the steering column in the FULLY ADVANCED position.
4. Set the distributor points just opening; to do this, slacken the pinch-bolt on the ignition lever under the distributor head and rotate the head bodily the required amount and re-tighten the pinch-bolt. The correct gap for the points when fully opened, is .012".

GROUP 11. The F.A.6 nark is 16° before T.D.C. (4-1/2 flywheel teeth).

The procedure is the same as for Group 1. except that the sump need not be removed in order to rotate the oil-pump through 180.

GROUP 111.The F.A. mark is:-
10,12 h.p. 1939-47 11° (3 flywheel teeth)
14 h.p. 1939 8° ( 2 flywheel teeth)
14 h.p. 1940-47 11° ( 3 flywheel teeth)
16 h.p. 1937-39 8° ( 2 flywheel teeth)
16 h.p. 1940-47 11° ( 3 flywheel teeth)
20 h.p. 1937-39 12° ( 3 flywheel teeth)
20 h.p. 1940 11° ( 3 flywheel teeth ) P.T.O.
before the T.D.C. mark on the flywheel.
1. Rotate the engine until the F.A. mark on the flywheel is in line with the pointer in the clutch housing aperture with both valves on No. l cylinder closed.
2. The rotor arm of the distributor should now correspond with No. l cylinder H.T. lead terminal. Should the engine have been stripped and re-assembled the rotor may be up to 180 away from the No. l cylinder position; in such cases remove the oil pump and rotate the pump and distributor driving shaft in the required direction until the correct position is obtained. The oil pump is inside the sump, which should, not, therefore be fitted until the timing is definitely correct.
3. Set the octan selector at '0' on the sliding scale.
4. Set the distributor points just breaking by slackening the 1/4” pinch-bolt at the base of the distributor head and rotate the distributor bodily in the required direction. Do not forget to re-tighten the pinch-bolt. The correct gap for the points when fully opened is .012".

Octane Selector.

The octane selector is fitted direct to the disttibutor head and comprises a sliding portion controlled by an adjusting screw. A calibrated scale marked with R (retard) and A (advance) with a number of divisions between is provided.
The ignition is normally set with the line on the sliding portion against the '0' on the scale, thus leaving two divisions further possible advance and five divisions further possible retard. This position is correct when using a high octane value petrol and with a clean engine, but should it be necessary at any time to use a low grade petrol or should pinking develop as a result of a need for decarbonising, the control can be retarded a little by turning the screw in an anti-clockwise direction. Do not forget to revert to the original position when again using high grade fuel or after decarbonising, as only in that position will the maximum performance be obtained.
Rover 10 1946 RHD
Rover 10 1947 LHD
Rover 12 1947 tourer LHD
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digcot65
Posts: 360
Joined: Sun Apr 19, 2020 1:34 pm

Re: IGNITION TIMING AND SOLEX 30 FAI ADJUSTMENTS

Post by digcot65 » Sat Apr 23, 2022 12:48 pm

Thanks for your excellent help He had a problem on his engine where a valve stuck in the guide and the result was it became bent .I have a feeling,that the valves are not being lubricated in their guides .My Wife has to go into hospital Monday,to have a pacemaker fitted so I am going to be busy for a while .When time allows I want to check the small holes in the rocker arms are clear I take it these are the there to supply oil to the valve stems .I can`t think of any other easont the valves should stick in their guides

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