engine and drivetrain I bought the "American Gangster" car

[JsnPpp]

Nice car! Interior looks great and from the photos the Inka looks spot on.

$3K seems to be a fair price to me.

~Jason

[Scott Sislane]

Do you still own the car? You’ve got piano tops, interesting.

 

Scott

[Conserv]

Scott,

 

E12 heads took piano-top pistons. And E12 heads were originally on all U.S. 2002’s from mid-1972 through the end of production in 1976 (except 1976 49-state versions, which used E21 heads).

 

Piano-top pistons came in a range of compression ratios, ranging from, perhaps, 8.3:1 to 9.5:1. The height of the piano obviously determines the compression ratio.

 

Best regards,

 

Steve

 

Edited May 31, 2020 by Conserv

[Scott Sislane]

4 minutes ago, Conserv said:

Scott,

 

E12 heads took piano-top pistons. And E12 heads were originally on all U.S. 2002’s from mid-1972 through the end of production in 1976 (except 1976 49-state versions, which used E21 heads).

 

Piano-top pistons came in a range of compression ratios, ranging from, perhaps, 8.3:1 to 9.5:1. The height of the piano obviously determines the compression ratio.

 

Best regards,

 

Steve

 

 

Thanks Steve, I didn't realize any of the carb'd 02's came stock with piano tops. (my 76 did not)

Scott

[Conserv]

1 minute ago, sislane said:

 

Thanks Steve, I didn't realize any of the carb'd 02's came stock with piano tops. (my 76 did not)

Scott

Scott,

 

My ‘76 is a 49-state, so E21 head. It’s original 8.3:1 pistons (maybe 8.1:1) were flat tops. Is your ‘76 a 49-state version, or a California version?

 

Best regards,

 

Steve

 

 

 

[Scott Sislane]

2 minutes ago, Conserv said:

Scott,

 

My ‘76 is a 49-state, so E21 head. It’s original 8.3:1 pistons (maybe 8.1:1) were flat tops. Is your ‘76 a 49-state version, or a California version?

 

Best regards,

 

Steve

 

 

 

I think mine was CA. (My original motor is sitting in my shed.)

 

It looks like his piston is mark 89.47, 2nd over bore?

[Conserv]

1 hour ago, sislane said:

I think mine was CA. (My original motor is sitting in my shed.)

 

It looks like his piston is mark 89.47, 2nd over bore?

Scott,

 

Yep, second overbore, so not the original pistons. Somewhere on here there are dimensions for the various piano-top heights and how they correlate to compression ratio.

 

The U.S. 1974 models are showing an 8.3:1 compression ratio (first photo). The U.S. 1976 models are showing an 8.1:1 compression ratio (second photo), and not distinguishing between 49-state (E21 head) and California (E12 head) compression ratios, even though, elsewhere in the specs, there is recognition that both versions exist. 
 

So... could 1975-76 2002’s share a flat-head piston between E12 and E21 versions, to achieve that 8.1:1 compression ratio? (The combustion chambers of an E12 and E21 head, however, might be sufficiently different in volume that flat top pistons would yield somewhat different ratios, when used with the different heads. I don’t know.)

 

My factory service manual was last updated September 1975, and it is blissfully unaware of the 8.1:1 ratios we find advertised for the U.S.-spec 1975-76 cars. And the specs in the 1976 sales brochures suggest that the 49-state and California versions produced exactly the same horsepower, torque, etc. If that were true —I doubt it is — why would BMW have gone to the trouble of having two versions for 1976, with different heads, different cams, etc.?
 

So... un-answered questions!

If your ‘76’s original engine has an E21 2,0 head (assuming the head’s casting date is close to but no-later-than the car’s manufacturing date), it was a 49-state version. The original pistons were flat tops. If your 76’s engine has an E12 head (assuming the head’s casting date is close to but no-later-than the car’s manufacturing date), it was a California version. The original pistons were... well, that’s what we need to determine!

 

Best regards,

 

Steve

 

 

 

 

Edited May 31, 2020 by Conserv

[Scott Sislane]

I guess I found it interesting that  mike472 did not appear to have realized the motor had been modified... (8 year old post, I know)

 

Scott

[Conserv]

15 minutes ago, sislane said:

I guess I found it interesting that  mike472 did not appear to have realized the motor had been modified... (8 year old post, I know)

 

Scott

You’re right. We only know for certain, however, that the engine had been rebuilt and “re-pistoned.” I can’t tell whether those are 8.3 (original compression ratio) or 9.5 (maximum available OEM) pistons.

 

Now I need to find those piano-top heights!

 

Best regards,

 

Steve

 

[COOP]

3 hours ago, sislane said:

I guess I found it interesting that  mike472 did not appear to have realized the motor had been modified... (8 year old post, I know)

 

Scott

 

Well...with all respect to mike472, given that he gushed that “This car is in such good original condition I almost cant believe it“ while describing a car with an auto-to-manual conversion, a Sahara-to-Inka color change and a non-oem reupholstered interior, you can’t find his knowledge level about the motor specs to be all that surprising! Just sayin’. Cool story though, what with the movie history and all...I wonder if he still has the car.

[Scott Sislane]

5 minutes ago, COOP said:

 

Well...with all respect to mike472, given that he gushed that “This car is in such good original condition I almost cant believe it“ while describing a car with an auto-to-manual conversion, a Sahara-to-Inka color change and a non-oem reupholstered interior, you can’t find his knowledge level about the motor specs to be all that surprising! Just sayin’. Cool story though, what with the movie history and all...I wonder if he still has the car.

 

I was wondering the same, if he still has it. Planning to DD it, possibly not. And yes, far from original anything but great find.

[mike472]

10 hours ago, sislane said:

Do you still own the car? You’ve got piano tops, interesting.

 

Scott

Scott

 

i still own the car. 9 years now. Runs great with the new Korman rebuilt head I put on it. CR is 8.31-1 I think.  It needs a paint job but it’s still in great shape 
I still have my estorilblau car too.  Don’t use me as an authority on the fine points regarding compression ratios. The car is certainly not original but was in great shape when I bought it. Still is

Mike

[mike472]

 Just got exercised along with the one behind it

[Scott Sislane]

Excellent! thanks for the update & glad you still have it. Your other 02 looks very nice as well.

 

Scott Sislane

[mike472]

10 hours ago, sislane said:

Do you still own the car? You’ve got piano tops, interesting.