6 replies to this topic

[Jimmyarm]

Hi All,

I bought me on of these http://www.maplin.co...e...ll&doy=1m11
today

I checked the dwell on my points and it was reading 47.2 degrees, is this normal as haynes says is should be 57 +/- 5 degrees !

She runs ok (ignition wise) at the moment but I was going to change the points prior to my RR session on friday so everything is tip top

Jimmy

[fikus01]

if you're going on a rolling road they should check and change all heat if required anyway!! they mite put it back to 47 degrees because that gives better performance!!

[dklawson]

If your car is fitted with the correct distributor and you're supposed to have 57 degrees of dwell but you have 47... no, it's not right. Dwell is a way of electronically measuring the gap of the points. When you open up the gap, the dwell number goes down so your measurements would be consistent with points that have eroded a bit without building up the little stalactites that sometimes form. Fit your new points and adjust the gap/dwell before your rolling road.

[Jimmyarm]

Thanks Guys,

I am not 100% I was measuring it right to be honest, will have another look at it tonight and adjust as required Or I might just take the whole lot to Slarks and ask Neil to show me how to do it ! lol

[dklawson]

I seldom work (or worked) on American cars as I grew up working on German, Japanese, and British cars with my friends. However, in the 1970s my father owned a typical General Motors family sedan and I agreed to tune it up for him once. I was truly impressed by one feature on 8-cylinder Delco distributors, something I wish every other distributor manufacturer had incorporated.

On the side of the Delco distributor body was a little sheet metal window that could be slid open. You could insert an Allen (hex) key through the opening and use it to adjust the dwell of the points WITH THE ENGINE RUNNING. Instead of using feeler gauges and taking the dizzy cap off several times, setting the points was as easy as setting a gap good enough to start the engine, hooking up your meter, and turning a hex key... one time. The whole process took less than 10 minutes. It was a brilliant idea.

[Jimmyarm]

Do you reckon I can bodge one of those into the minis dizzy hole ?

So are you supposed to check the dwell with the engine running ? Thats what I was doing and it was the 47.2.....

That new multimeter I bought is great, so many things you can do and it tells you how to do it all in the manual ! For £26 I think everyone should get one

[dklawson]

Yes, you must measure dwell with the engine running. It's basically measuring the the amount of time the coil is charging so you can't measure it unless the points are opening and closing.

I've got a few multimeters. I have a couple of old, but nice, ones I use for most tasks. I also have a couple of dirt cheap Chinese ones that I bought from Harbor Freight. I think Harbor Freight would compare to a low budget version of your Machine Mart stores. Those Chinese meters are cheap enough to carry in the boot of the car (just in case). Of course, they don't measure dwell like your new meter!