1974 tii resurrection, new discovery

[JLENHAM]

Still working on getting this tii to run well.

 

It is probably easier to list what I have NOT done rather than what I HAVE done.  Search for previous posts if you are curious...

 

This weekend I changed out the intake manifold gaskets and discovered that the head is an e21 2.0 from 1983.  

 

After putting everything back together I got no improvement in running.  It starts but misfires like the spark plug wires are not in the correct position or timing is seriously off.  I pulled the plugs and they were all evenly black with carbon.  

 

I am back to thinking I have a spark issue despite having changed out all the ignition parts except the coil (swapped one from another car that is known good,) and the distributor.

 

Pump is set up, fuel pressure good, WUR working, timing on cam, flywheel, crank pulley and K-pump all line up.

 

Is there anything about the 1983 head that should raise suspicion?  The distributor does spin clockwise.

 

 

[jireland2002]

First - You probably know the tii had popup pistons and an E12 head.  So I hope the engine's pistons match the E21 head.  There is nothing wrong with a 1983 head.  It was a replacement for the original that was probably damaged.

Have you checked compression?

[JLENHAM]

I am still learning the various piston/heads that were used.  I thought I understood that the e21 head was correct, not so if I am reading right, that would be correct only on the 1976 and then continue with the 3 series.  

 

I don't know very much about the history of the car.  The owner lent it to his parents sometime in the 90's, they used it until around 1997 when they either got tired of it or in needed repair.  The owner related that when he finally had a place to store it his parents revealed it was in a field near a repair shop.  He had it transported back to his garage where it has sat ever since.  I think he got the car sometime in the mid to late 80's so it is likely the head was changed out prior to his ownership.  Hopefully there was consideration for the pistons/interference as well.

 

Great idea on checking compression.  I should have thought about that very basic check much earlier!  It is easy to get your mind headed in a direction... forest for the trees and all that.  

 

Photo is "as found."

 

Thanks

Edited July 28, 2020 by JLENHAM

[Conserv]

4 hours ago, jireland2002 said:

First - You probably know the tii had popup pistons and an E12 head.  So I hope the engine's pistons match the E21 head.  There is nothing wrong with a 1983 head.  It was a replacement for the original that was probably damaged.

Have you checked compression?

+1

 

An E21 2,0 head with a June 1983 casting date (6 nubs surrounding “83”), and an un-drilled fuel pump boss, could be a replacement head for an e21 (a 320i or 320is) or, conceivably, a 1976 49-state ‘02 — although many of the ‘76 ‘02 replacement heads came with drilled fuel pump bosses.

 

Ordinarily, a 9.0:1 E12 piston (piano top), standard on a 1974 tii, would not work with an E21 head. So either (a.) your block does not have its original pistons, or (b.) the combustion chambers and/or possibly the pistons have been modified to accommodate the pairing of E12 pistons with E21 head.

 

Start with jireland2002’s recommended compression check. Maybe a borescope could identify the pistons without removing the head. Not likely, but possibly.

 

But, given the car’s history, you may find it worthwhile to pull the head just to figure out whether you’ve got the basics for a decent-running tii.

 

Regards,

 

Steve

 

[TobyB]

Oh, you can slap an E21 head onto the mid- lift tii pistons.

 

They only hit a little bit, and only at first.

 

Check the block, though, for casting dates and identifying marks- you could have a different

block, too.

 

A borescope should be able to make sense of the dome shape.

 

+1 for compression, and then leakdown if compression isn't conclusive.

 

hth

 

t

 

[Guest_anonymous]

24 minutes ago, TobyB said:

Oh, you can slap an E21 head onto the high- lift tii pistons.

 

They only hit a little bit, and only at first.

 

For a short period of time, then it stops. Until dissasembly 

 

Fixed this for you

 

[TobyB]

thanks, Da_ron!

 

t

[JLENHAM]

Thanks for the replies!

 

I can confirm that the block is a match for the VIN so is original for the car.

 

I wish I had some insight on why the car was taken off the road.  I mentioned the non-original head to the owner and he doesn't have any knowledge of the change so I assume it was done prior to his ownership and he drove with this set up throughout college and into the early '90s or so.

 

Since I have had the car the majority of the work I have done has been around the fuel system.  When I got the car there was only a few strands of left over belt on the K-pump, gas tank full of "mulch" etc. so that seemed the likely place to start.  I over looked doing the most basic test, compression.  It was all still work that needed to be done though.  The goal is to get the car running and driving reliably then let the owner ponder a complete restoration.  I did not factor tearing the motor apart to get there!

 

I will report back on compression.

 

John

Edited July 30, 2020 by JLENHAM
Corrected "non-original block" to head