ignition timing

[bob]

Hi. Thanks for comments on chassis cracking. but my chassis has no corrosion whatsoever-no rain in Spain.The cracks appear to be metal fatigue.
Can you help with ignition timing. Are there strobe marks on flywheel, if so is it tickover vacuum pipe disconnected.Any adjustment for unleaded fuel. My car is 1100cc 1989 made in Spain. In our village there are a great number of Renault 4s all pottering about rust free!!!!

 

[malcolm]

Is this page any use for the timing: http://www.renault4.co.uk/tech-points.htm

I tend to set the timing to about halfway between the two marks on the flywheel. Partly to retard the ignition a little for unleaded, and partly because I can never remember which mark to line up with. Ultimately the best setting is as advanced as you can get it before it hints at pinking, and with the effects of wear every car will have a different setting these days.

I'd be very interested to see your chassis crack if you could post some photos. I've never heard of fatigue on a Renault 4 before - they are too softly sprung and damped for any real forces to get into the chassis.

 

[bob]

chassis cracking

Hi. I will take photos in Spain and send them when we get back to England at end of August

 

[bob]

hi have returned from spain here are phtos of cracks in rear chassis legs between damper mountings and axle mountng hope you can see that there is no corrosion,bob

 

[malcolm]

I've never seen anything like that before. Quite right - they do look like stress cracks, and the chassis does look rust free too. It'll be rust free on the inside in that area as well.

Chassis cracks tend to be around damper mountings - there is way more force through the dampers than the springs. Yours look like they were initiated at the end of the weld holding the damper mountings on. UK cars don't have that weld - the damper mountings are spot welded on over here. I suspect seam welding has created a really high stress area which has cracked, and once the crack was there it spread.

It's fixable though. It's worth drilling a hole beyond the end of the crack so it can't develop any further, then welding plates over the crack on each side of the chassis members and at the bottom. The plates should spread the load away from the bit that's causing the cracks so should stop them from happening again.