Advancing the ignition on a bog standard 3.9 Rover V8

[Horse_Apple]

Advancing the ignition on a bog standard 3.9 Rover V8

The car doesn’t used much but I noticed this weekend that it is utterly gutless after a recent service.

It’s almost certainly down to insufficient advance. I like to run my RV8s just to the point of pinking when the pedal is buried.

Rather than take it all the way back to the garage for them to do, it seems like a relatively simple job of trial and error.

The sort of job that would fill a Saturday afternoon most rewardingly.

The issue, therefore is what on earth do I do to actually change the advance? Obviously, it involves furtling around with something in or around the distributer but other than that I am pretty much in the dark.

If anyone can’t point me to an idiot’s guide on the web I would be very grateful. All the pages I’ve found so far have been about tuning performance RV8s and not normal ones.

Thanks.

[GreenV8S]

Horse_Apple said:

I like to run my RV8s just to the point of pinking when the pedal is buried.

...

The issue, therefore is what on earth do I do to actually change the advance? Obviously, it involves ...

There's a discrepancy between the two bits quoted above. On the one hand you seem quite nonchalant about running very aggressive timing. How good do you really think you are at hearing detonation? By the time it's heavy enough to hear over the engine at full chat it's very heavy indeed, and if you rely on an untrained ear to notice it you are liable to end up with long term detonation and a broken engine.

On the other hand you don't sounds as if you have any first hand experience of changing the timing, so what does it mean when you say "I like to run ..."?

To finally answer your question, the procedure is exactly the same on a mildly tuned engine as on a highly tuned one, except that you may find you find MBT before you reach the knock limit.

[Horse_Apple]

GreenV8S said:

Horse_Apple said:

I like to run my RV8s just to the point of pinking when the pedal is buried.

...

The issue, therefore is what on earth do I do to actually change the advance? Obviously, it involves ...

There's a discrepancy between the two bits quoted above. On the one hand you seem quite nonchalant about running very aggressive timing. How good do you really think you are at hearing detonation? By the time it's heavy enough to hear over the engine at full chat it's very heavy indeed, and if you rely on an untrained ear to notice it you are liable to end up with long term detonation and a broken engine.

On the other hand you don't sounds as if you have any first hand experience of changing the timing, so what does it mean when you say "I like to run ..."?

To finally answer your question, the procedure is exactly the same on a mildly tuned engine as on a highly tuned one, except that you may find you find MBT before you reach the knock limit.

Cheers Green.

I have ears that remind people of a wingnut, so hearing is pretty good

Whether TVRs or RRCs I've allways had them set to the point that they pink on full throttle, under load and then brought back a degree or two. That has allways given me what I've wanted.

With one of the RRC's the timing is far too retarded meaning it won't even climb a hill without having to bury the throttle and kick right down.

What I've done in the past is pay someone to advance the timing, then I test, they advance a bit more, then test, then advance on and on until we find the pinking point and just bring it back a bit.

This RRC is an old car that doesn't get rassed, full throttle rarely if ever used and I fancy tinkiering with the advance myself. Whenever the mechanic does it it is a simple twiddle of something that takes less than a moment, so it can't be mechanically complicated. It is that aspect I'm looking for help with rather than the actul guaging of the sweet spot as I can do that easily enough.

[gog]

Slacken the screw on the distributor clamp with a 9/16th socket, then turn the distributor anticlockwise to advance.

[GreenV8S]

Horse_Apple said:

Whenever the mechanic does it it is a simple twiddle of something that takes less than a moment, so it can't be mechanically complicated. It is that aspect I'm looking for help with rather than the actul guaging of the sweet spot as I can do that easily enough.

Well in that case, assuming you have a timing light and know how to use it (so you can find the current setting and get back to it just on the off-chance that things go horribly pear-shaped), all you need to do is slacken off the dizzy clamp bolt and swing the body (anti-clockwise to advance) then re-tighten. Before you do it, make sure you know what a 1 degree movement looks like. It's not very much at all. You don't need to turn it very far to get so far away that the engine won't run.

[Horse_Apple]

Thanks Chaps.

Seems simple enough. Will let you know if it works or whether there is an nice RRC non runner going up on the ads.