Opposite Knock

Kinja'd!!! "razorbeamteam" (razorbeamteam)
06/15/2018 at 09:39 • Filed to: None

Kinja'd!!!0 Kinja'd!!! 6
Kinja'd!!!

The ignition issues continue in the Rover after installing the MSD 6A, a new coil, and a new set of plugs. I have a new cap and rotor on the way as well, but last night I tried some things and managed to get rid of the missing/stumbling. I cleaned the buildup off of the inside of the cap contacts, and checked all the wire terminals. #4 looked a little rough as I had previously repaired the distributor end of that wire. I redid my repair and all cylinders seem to be firing. Now the only issue I have is a bad knocking throughout the rev range, but it is worst at idle.

I’ve done some research and now I believe my plug gaps may be to blame for this. I set them at ~0.042 when I installed the MSD and the coil, stock specs are 0.033-0.038. I’m wondering if I went too big or if I should bump it up further. Timing is set at ~7 deg. advanced. Any obbos have opinions/experience on this?


DISCUSSION (6)


Kinja'd!!! punkgoose17 > razorbeamteam
06/15/2018 at 10:31

Kinja'd!!!1

This is interesting. The knock would indicate your spark is early. With it improving at higher rpm it would indicate your spark is early. I think a wider gap would make a later spark, just guessing. Timing is at -7. Idk what stock is. I would keep dialing back the timing -9 -11 until the knock goes away. Looking for the timing. Your timing marks are lying to you:

!!! UNKNOWN CONTENT TYPE !!!

Keep dialing back the timing until there is no knock.

http://www.v8engines.com/electrics-1.htm


Kinja'd!!! razorbeamteam > punkgoose17
06/15/2018 at 10:42

Kinja'd!!!0

Interesting... Timing is 7 deg. before TDC, stock is 6 degrees before. Are you saying advance it more so its 9-11 deg. before TDC, or to retard it so its actually after TDC?

And if the timing marks are off, I suppose I could time it by “feel” and just adjust the timing til I get no knocks.


Kinja'd!!! crowmolly > razorbeamteam
06/15/2018 at 11:03

Kinja'd!!!1

What kind of timing light are you using?

Certain ones don’t work with an MSD box.


Kinja'd!!! razorbeamteam > crowmolly
06/15/2018 at 11:13

Kinja'd!!!0

The timing light is an older hand-me-down from my dad’s high school hot rodding days. It’s pretty basic. I set the timing with the MSD disconnected though, just on the stock ignition.


Kinja'd!!! punkgoose17 > razorbeamteam
06/15/2018 at 11:17

Kinja'd!!!1

Adjust it so the timing is actually before TDC by “feel”.


Kinja'd!!! brianbrannon > razorbeamteam
06/15/2018 at 12:14

Kinja'd!!!0

If you have knocking at idle and through the rev range its probably a bearing knock