Innova Digital Dial-Back Timing Light...1 Week

[bunnspecial]

I bought one of these fancy digital dial back/tach combo lights last week.

I went to use it today only to find that now, for whatever reason, the dial-back function won't work. Regardless of where it's set, it still flashes with the spark. That kind of kills the point of it, as I already have a handful of standard lights that I'd dare say are nicer than this one...

Hopefully they'll warranty it, but it's still a pain.

 

[Motu]

Still flashes with the spark ?...? Of course it will. So pointing at the crank pulley it isn't retarding the mark ? Like, set the dial at 10 deg and it will strobe on the TDC mark, when it is 10 deg with the dial at zero ?

 

[bunnspecial]

Still flashes with the spark ?...? Of course it will. So pointing at the crank pulley it isn't retarding the mark ? Like, set the dial at 10 deg and it will strobe on the TDC mark, when it is 10 deg with the dial at zero ?

Correct. Pointing at the crank pulley shows the mark at the same position(in this case 15º at idle) as a plain non-dialback light. Changing the setting on the back of the light does not move the mark at all. I'm sure you know this, but if it were working correctly if the ignition is 15º BTDC and I set the dialback light to 15º, the timing mark should move to the TDC mark.

My preference/practice on this engine, per several MG mechanics, is rather than set idle advance, set max mechanical advance to 32º BTDC(vac disconnected). Since the engine timing marks only go to 20º, a dialback light is the easiest way to set it.

I may revert to the old set-up I had before the rebuild where I rotate the engine to TDC then put an orange mark at the 20º BTDC mark(I always paint the crank notch white). You can then use the second mark to measure out to 40º with the timing scale on the valve cover.

 

[Motu]

I used to always set motorcycles to max advance, and some Euro cars were set at max...but most cars were set at idle, and that's what we did. But when these adjustable timing lights came along, then yes, setting to max advance was an added check. Some engines only had a TDC mark, and we had to calculate the degrees and mark the pulley...static timing with those. They say 32 degrees for those engines ? I used to set my Kent engine to 38 max, and then bring up mid range and idle even more over stock...it had a pretty wild cam and low vacuum at idle. The BMC head was very prone to ''pinking'' (English term) and you didn't want to over advance them...you have a modified head though ?

 

[bunnspecial]

My head's been ported and polished. The guy who did it, IIRC, did round off some sharp edges in the combustion chambers, but at least I'm told that's more to reduce run-on(another notorious problems on these engines). You don't want to get too aggressive with it, either, since one of the primary goals of this build was increasing the C/R(target 9.5:1, actual measured/calculated 9.6:1) and all that corner rounding increases combustion chamber volume.

The 32º number came from John Twist, who's something of an MG guru stateside. He went to London in the 70s and worked for University Motors for a few years, then came back home to Michigan and opened a repair shop under the same name that he ran up until just a couple years ago. He says it's for every B series engine except a Twin Cam, although I've gone a bit over it when I found that my car ran better and knocking wasn't an issue with high octane gas.

 

[Motu]

We used to take the point off the ''heart'', that was one of the contributors to running on, and became a factory mod....also used to get rid of the projected nose (N9Y) and fit a normal plug (N5 I think). But modern tech should have these things running well without our bodge ups from back in the day. I tried to run one of my 1800 (Landcrab) on regular, and had to retard it so far I couldn't get up my drive.

 

[JeffKeryk]

I use a timing tape on my classics.
I have a nice dial back light; I kinda like my old Sears Penske best.

 

[George7941]

I have had a Innova digital adjustable timing light for the last twenty years and it still works well.