Timing Big 7

[Hobbo]

Hi , I have got one book that say's timing is at T.D.C., and the other saying 12mm measured on the flywheel B.T.D.C.,which is the correct setting for a Big 7 Thanks, Mike.  p.s. All the best to every one what a great forum this is.

[Reckless Rat]

The two differing values probably relate to static timing and dynamic timing. If you're not happy with the car's set up, setting the distributor with points just opening at TDC should allow the engine to start. You can then advance the distributor if necessary to find the best running. The distributor will automatically advance the ignition above tick-over speeds unlike earlier Sevens which had manual control. However..." if it's not broke then don't mend it" is always a good adage.

Don't lose sight of the fact that a Big Seven shares very little in common with the earlier models, apart from the name. The engines are completely different and few, (if any) parts are interchangeable although they may at first appear so. The car was later renamed the Austin 8.

[John Mason]

The short answer is I don’t really know. However all engines I have ever worked on all fire just before TDC so I would try the 12 mm on the flywheel to start. Then when the engine is running slight adjustments with the dizzy until the engine sounds ok.

John Mason

[Barry Townsend]

Be careful when setting up TDC. I initially used the flywheel markings but when I double checked with dial gauge in the plug hole it was quite a way out. I made a little pointer fixed to the camshaft pulley and then used a strobe / bit of a faff  but worth it

[Rogerfrench]

The two differing values probably relate to static timing and dynamic timing. If you're not happy with the car's set up, setting the distributor with points just opening at TDC should allow the engine to start. You can then advance the distributor if necessary to find the best running. The distributor will automatically advance the ignition above tick-over speeds unlike earlier Sevens which had manual control. However..." if it's not broke then don't mend it"  is always a good adage.

Don't lose sight of the fact that a Big Seven shares very little in common with the earlier models, apart from the name. The engines are completely different and few, (if any) parts are interchangeable although they may at first appear so. The car was later renamed the Austin 8.

The Austin 8 was a very different car, though the engine was like the Big7. The 8 had a totally new chassis with semi-elliptic springs, it was almost unit construction.

[Hobbo]

Thanks for all your replies' I think I will just check it first. The engine on start up seems to want to be pushing back I think some people say it's hydraulic-ing  [a bit too far advanced] and work from there.

["Slack Alice" Simon]

It sounds a bit advanced.

Take off the cap, move the engine on the handle to remind yourself which way it rotates.

Loosen the distributor clamp and move the whole distributor a bit in same direction that the arm goes.

How much is a bit? One of the corners moves half an inch or so.

If still kicking back, (its not hydraulicing, that is something different) repeat until it starts easily.

Cheers

Simon

[Hobbo]

Many thanks I thought that may be the problem Mike

[Chris KC]

If in doubt, too far retarded is a much safer place to be than too far advanced.

In the old days you would have driven up the nearest hill and advanced the timing at the distributor until the engine just started pinking, then back a whisker. Sadly(?) with modern fuels this no longer works.