engine and drivetrain 76 E21 2.0 Head on my motor?

[72_02]

I am still ironing out issues with my engine and how it runs. It's a lot smoother, especially after a quick sanding of the points as I'm waiting for a new dizzy cap.

 

But I would like to replace the spark plugs - I ordered ones thinking I had the original engine. (my car is a '71 2002 - recently found out it's actually not a 72...)

 

But, it has a 76 E21 2.0 stamped on the head. I pulled a plug, it's a WR7BP. I ordered WR7DC+. Is that even the original head? Or is it is so simple - an e21 head from 1976?

 

The BP is much shorter. Does this still matter?

[jrhone]

Your engine may not be original or it may have the original block bot a new top end. That's the thing about 45 year old cars. No two are alike and lots of things have been done to them. I'm not an expert but I thought spark plugs should be the same for all 02s.  Differnent heat ranges are available but a plug for a 71 should be the same for a 76. 

[Conserv]

22 hours ago, jrhone said:

Your engine may not be original or it may have the original block bot a new top end. That's the thing about 45 year old cars. No two are alike and lots of things have been done to them. I'm not an expert but I thought spark plugs should be the same for all 02s.  Differnent heat ranges are available but a plug for a 71 should be the same for a 76. 

 

+1

 

What he said!

 

Just below or near the "E21" and "2,0" castings is the casting date for the head, a two-digit year date surrounded by one to twelve nubs representing the month in that year.  Here's the original April 1976 (4 nubs around "76") head from my April 23, 1976 car.

 

(By the by, a 1972 U.S. model BMW was a car manufactured after July 1971 and before September 1972.)

 

Regards,

 

Steve

 

 

 

Edited August 28, 2016 by Conserv

[TobyB]

Then look at what's on the VIN pad on the block right next to where the starter bolts to it.

If it matches the VIN on your car, it's original.  If it has something else there, it's not.

A pic helps- BMW used a bunch of codes throughout the years to identify replacement

blocks.

 

Your head's not original, but your block may be.

 

You want an extended plug- the short plugs aren't right for the head.

May I suggest NGK BP6ES?  Part number 7333 in packs of 4...

 

t

 

[jrhone]

That Bosch plug will work fine...although I think I have had better luck with the NGK BP6ES plugs.  NGK has this new fangled Iridium plug I am trying in my car and they are working pretty damn good!  They are BPR6EIX.

[72_02]

I'll see when I get it back

 

Drove all day Saturday, went really well, even up to 70mph, then while driving home it gave up. Jolting started an hour from it's home. Tow truck came and took it to the shop... 2nd visit to a mechanic ever! (Could be a sign)

 

Hopefully it's something simple that happened. I re-did timing by ear on the highway and limped about 6 miles, but then jolting started in 1st and 2nd gears at low speeds, and the car totally stalled. Ah well, I tried! New rotor and cap replaced on the highway too, re did timing again, nothing. The coil was very hot.

 

BTW I measured my coil on idle fluttering around 11.7 up to 17v. I thought I read it wasn't meant to go above 12... ?

 

 

I shall see.. hope it's not damaged from driving :/

Edited August 30, 2016 by 72_02

[TobyB]

Bosch plug wires can do that.

 

Points, too...

 

t

[Simeon]

Check your low tension wiring.

 

Jolting, as you describe it, sounds like the ignition cutting out entirely.  Could also be your coil lead I suppose. 

 

If if you are seeing 17V at the coil then you will need to check the voltage regulator is working. 

[ray_]

WR7BP are platinum plugs. I foul them rather quickly in M10's.

 

Lake test them, IMO.

 

Cheers,

[Simeon]

What points gap do you have? The hot coil may be a sign of incorrect dwell. 

[72_02]

No points, im using a pertronix ignitor series I.

 

I wonder if the voltage regulator is wired wrong.

 

I did rewire it. Checked, double and triple checked that wiring, too.

 

I will look at the diagrams in my manual.. 

 

Regards low tension wiring- where will that wire come from exactly ?

 

[TobyB]

If you're metering the coil primary with a DC DVM as the car's running,

you 'll see some pretty high, probably erratic voltages-

when the power to the coil's unhooked by the pertronix,

the magnetic field in the coil collapses, and makes the spark on the secondary.

However, the primary's wound right in there too, and it gets some share of that magnetism.

So there'll be a spike on it.  That's why points style ignitions had a condenser- it

kept the primary from kicking back through the points, arcing them, and in the process

pulling energy from the secondary.

As any points- experienced person will tell you, without the condenser, the car won't run.

Without the right value condenser, the points won't last very long.

 

Try metering it AC, and seeing what you get!

 

t