how do I determine the year of my L20B motor

[DAK]

How can I determine the year of my L20B motor? I need to set point gap and see if there is an electronic igniton change overkit available.

[datzenmike]

Point gap 0.022" is close enough. Timing is more critical.

 

 

 

These engines easily outlast the cars they came in and it's common to find a swapped L20B into a car that either had one or an L16/18.

 

I would say if the head casting located along the bottom of head between #1 and #2 plugs is...

 

A87 ... tough to say having never seen this combination but is they ever came on an L20B it was a very early one like the '74 610. This is the earliest L20B car I know of.

 

U67 head then '75-'77

 

W58 head '78-'80. These all had electronic ignitions

 

Keep in mind heads can also be swapped.

 

Next might be the carb and pollution controls used. The BCDD changed over the years

[racerx]

check your dwell also.  Been awhile but I think 52 degrees.  You can also go matchbox setup or pertronix. The latter have gone down in price since I bought mine like 12 years ago.

[distributorguy]

If your distributor is in good condition, you will find that your truck runs better with points than an electronic conversion.  

Dwell can be measured, but given that I have well over 30 dwell gauges and none of them hold their "tune" longer than 1-2 uses, I'd recommend to just do an accurate job setting point gap with a feeler gauge.  To adjust dwell, you use a feeler gauge to change the point gap, so...

[racerx]

Points or running EI is to each his own.  I've had Pertronics on 4 cars and no problems.  I've had it on my Datsun for like 12 years, no problem and it's a bitch setting dual points. That's why I went Pertronics which is more like a Hall affect than EI. BTW, they have gone down in prices.  Now if I had points, how many times would I have to change them.  Just don't get the HOTsparks one on Ebay, heard people having issues with them - Knock offs of Pertronics from China. If you do get a pertronics, you will need a single point distributor.  Good Luck!

[banzai510(hainz)]

Who cares what year the motor is .

Whats the year of vehicle? then you know if its wired for points or the later EI type.

 

How about photos of the distributor and the coil.

[DAK]

Internet gurus call out different spark plugs and different point dwells for different years-that's why I ask.

[Doctor510]

Internet gurus call out different spark plugs and different point dwells for different years-that's why I ask.

That is why they are internet guru's, only know how to read, have no practical knowledge of how and why...

[datzenmike]

As long as the points open it will run. Not the best way to run but it will run. 0.022" is good enough and will run for a couple of thousand miles before needing to be gaped again. And that's the problem with points.. they wear down (erode) and the gap changes and this affects the timing. EI distributors are virtually maintenance free. Set and forget them. Change the cap and rotor ever 3-5 years. The EI system also has a hotter spark than points. Good for higher compression, high RPM, lean mixtures.

 

Don't stress the points gap..... set something 0.018"-0.025". The timing is much more important.

[DAK]

Still need to know the year of my L20B if I order a EI conversion kit.

[datzenmike]

No you don't. Just order one for any year L20B. That would be '75-'77 truck for a points distributor. Just make sure it's for an L20B.

[bilzbobaggins]

Do you have a single point or duel point distributor? That's most likely what your vendor is looking for

[datzenmike]

Just thought of something.

 

Look on the side of your distributor for the part number. It begins 22100- ????? It's stamped on the side of the case. Get me that number and I can easily look it up to find what years and vehicles it was originally installed on. All L series 4 cylinder distributors will fit all other L series engines. It could have anything on it even converted to the later EI.

[banzai510(hainz)]

photo of the distributor inside would be best.

 

The L20s had a ring above the point lobe that needs to be machined off so the magnet ring in new kit will fit.

If you dont have tht eskill to do this and take the distributor completely apart then just learn to adajust the points till you fine a later Matchbox distributor with the timming mount(all together)

 

Or soembody has a L series points with a Pertronix already together with the mount and install that when one come up for sale.  I just got 1 and a spare point one I can convert. Keep falling in my lap. But I wont give them up as I got thru them.  Dsit failure is the msot common proplem(out of time ,points, bushing wear, spring broke)