spark scatter

[ecamiel]

Hi All

What amount (in degrees) of spark scatter is acceptable? How much vertical play is normal for the dist shaft?

I'ver checked old posts about reducing vertical play including plastic spacers, roller thrust washers etc. What works? What kind of plastic? How much free play should remain?

Thanks
Eric 64 S1 Hart

[paddy]

I would also try to eliminate other possible sources of scatter before putting it all down to the distributor. I found that as soon as the timing chain tension is just slightly out of spec, it seems to make a big difference to the scatter.

From experience, a few (3 or 4) degrees of scatter, measured at the crank, starts to have an adverse effect on how smoothly it idles but I don't won't have too much of an impact on driving.

Paddy

[Tonyw]

Eric,

I would suggest that 60 degree's plus or minus 3 degrees should be about right. Lucas distributors are notorious for being "sloppy" and frankly from experience not real easy to fix long term. Your dwell meter will show the variance then it is just a question of if a problem manifests itself. I have usually run the dwell at 50 degrees to allow for a bit of play myself.

TonyW