Dwell Angle on a 2.25 Petrol

[pvkd]

Extract from a posting on the web "The only way to properly set up ignition points is with a dwell meter."

So when setting the points on a 2.25 petrol do you try for the gap setting recommended by Land Rover or go for the dwell regardless of the gap measurement?

Also I have been using 57 degrees - what do you use?

However when I use 57 degrees I measure the gap at 0.012" versus Land Rover recommended at 0.015" is this OK?

Thanks

Paul

[I Leak Oil]

I don't think I've ever seen a official, published dwell spec. for a series truck. I went through this several years ago. Came to the conclusion that, yes, dwell is more precise than just a gap measurement but let's face it, it's not a race car and most of us only carry a feeler gauge. The points gap method is more than enough for a series truck.
Click..(that's me opening a can of worms....) go electronic ignition and forget about it.
Jason T.

[gudjeon]

I'll second the advice^^^^. I have yet to find a dwell value for L/R as well. Point gap has always been sufficient. The biggest thing with any points system is to check them periodically to make sure rubbing block wear has not closed this value. A little dab of grease (I mean small) helps with this.

I went with Pertronix a few years back and I was one who swore up, down, and sideways that I would never get rid of my simple points system.

[scott]

...most of us only carry a feeler gauge. The points gap method is more than enough for a series truck.
Click..(that's me opening a can of worms....) go electronic ignition and forget about it.
Jason T.

feeler gauge! geeze i just carry a book of matches, the carbord thickness is a pretty good gap setting devise and if it wasn't the point gap that stopped you, you've got the means to start a signal fire...

[pvkd]

Well I re-set the gap to 0.015" and the dwell changed to 51 degrees (and of course I re-set the timing). I will drive it like this to set how I like it.

So what timing setting are you using? - I am using 6 deg BTDC

Paul

[scott]

...
So what timing setting are you using? - I am using 6 deg BTDC

Paul

i've heard lots of things will affect the optimal timing setting, like octane and quality of spark. when i tune, i set fuel mix first, then idle and third the timing which i adj 'til it idles the smothest. i've made jokes on this board about beer timing but it is how i do it

[junkyddog11]

Paul, I checked my notes and the dwell should be 50 +/- 2 deg as acceptable (no idea where I got that other than generally accepted basics). Which would agree with the result that you have. It seemed as if the 57 deg would be a little high. Never experimented with small gap /long duration as the standard point setting has generally achieved excellent results.

[pvkd]

Matt,

Thanks for checking.

Paul

[daveb]

I thought it was 57 or 58. Or get a Pertronix...

Matt,

Thanks for checking.

Paul

[pvkd]

Dave,

When I set it to 0.015" the dwell is about 50-51 degrees. I did have it at 57 but the point gap goes to 0.012" or so.


Paul

[junkyddog11]

I thought it was 57 or 58. Or get a Pertronix...

I've heard that and don't pretend to be a points expert by any stretch but as Paul mentioned (and had asked me earlier) when dwell is set at 57-58 deg the points gap gets very small.

I did a little messing around with a victim this past week and the seat of the pants / coffee mug / truck wisperer determination was that it ran best somewhere in between with the points gap at .014 and the resulting dwell of about 55 deg. This was during the setting up of a spanky new distributor.

[ghettoct]

dwell

been trying to figure the bugs out on my land rover and came upon an article in "land rover owners" magazine, spring of 2001 under LRO workshop and there the engine data for the project they are doing with a 2.25 petrol and the article said that the dwell angle reading is 60 degrees +/- three degrees. well with in what previous posts are with. iam right at 60.4 and it runs pretty good. had initially set with feeler gauges at 14 and 16 but it didnt run that great. threw gauges out and set by eyeball and then adjusted per dwell meter.