engine and drivetrain I bought the "American Gangster" car

[Scott Sislane]

4 minutes ago, mike472 said:

Very Nice!!

[Conserv]

2 hours ago, mike472 said:

... CR is 8.3-1 I think...

 

Pending real information from real authorities, I think the same: 8.3:1. This would be the same compression ratio it originally had.

 

The first photo below is of a ‘76 California version. Assuming these are either the original pistons, or replacements, this extremely-low piano top must give rise to the 8.1:1 ratio the brochures and manuals identify for 1975 and California versions of the 1976 models.

 

The second photo shows the pistons in Mike’s ‘74, a bit higher than the 8.1:1 in the first photo. So I’m guessing his are 8.3:1. And the third photo is of a 9.5:1 ratio piston, which is dramatically higher.

 

Best regards,

 

Steve

 

 

 

 

 

Edited May 31, 2020 by Conserv

[Conserv]

Uh-oh... I hate when facts intrude upon my simple solutions! ??

 

Here’s a set of — let me see, how can we determine the ratio? — 8.3:1 Mahle’s for an E12 head and they look just like the set I identified in my prior post as 8.1:1...

 

A ‘74 originally had an 8.3:1 compression ratio. But the replacement pistons in Mike’s engine certainly have piano tops higher than the 8.3:1 set. So does this make Mike’s set 8.6:1? Maybe.

 

Best regards,

 

Steve

 

 

Edited June 1, 2020 by Conserv

[mike472]

I didn’t really think this was an overbore. The car seemed to have 51k on it from the records it came with and the speedo reading. I wouldn’t have thought it needed to be rebuilt that early and it is the original block.
It was originally delivered in New Mexico. I have the original bill of sale and window sticker that came with the car. I figure I’m the 5th owner from what I see in the records.  Some rust is beginning to surface and it’s time to do this one before the tinworm really ruins it.  Spare tire well and front valance starting to go.  All critical areas are rust free. At least the mechanicals are sorted. As we all know there is always something else left to do.... but it’s fun!  Esty just sent me a rear seat delete kit for the blue car. Working on that tomorrow. 

[Conserv]

Mike,

 

New ‘02’s came out of the factory at standard bore: 89mm. They didn’t accidentally or intentionally bore new engines to 89.5mm. Given (a.) the shocking un-dependability of ‘02 speedometers, odometers, and speedometer cables, (b.) a five-digit odometer, and (c.) the history that is lost with each ownership transfer and simply with time, it’s difficult to know mileage for certain. My ‘76, at 105K miles, has four large volumes of receipts — literally hundreds of receipts — from day one until today. If I, uh... accidentally lose the last 95% of those receipts — or maybe if there was a really minor fire in my office — I’ve just proven that my one-owner car only has 5K... ?

It sure looks like a 5K car to me! ?

 

Just saying... ?

 

Best regards,

 

Steve

 

 

Edited June 1, 2020 by Conserv

[mike472]

Steve,
 

A lot of 74’s had bad engines that had problems with cylinder bores being tapered or out of round. They were fixed by BMW. Maybe they re bored this one before it left the factory. I think the records were good and looking at the cars condition when I got it seemed to bear out its mileage.  
It burns very little oil since I replaced the head and even before it didn’t use that much.  It had a bad crack in one intake runner that didn’t show up on initial inspection. I thought it would be a simple head gasket job. No dice. Had to take it apart again.  One clue I should have picked up was water in my air filter housing. With closed valves and a hot engine it was percolating up into it.   One new head casting later the engine was running great. Having Korman rebuild it for me didn’t hurt either. 
 

Mike

Edited June 1, 2020 by mike472
Got a name wrong

[Son of Marty]

Mike, a lot of 74's had ring problems caused by new guest workers diligently aligned all the ring gaps in a nice straight line causing blow by, depending on the fault any block thats not up to spec is pulled from the line and ether melted and recast of if feasible put into the rebuild pool, if it is a factory rebuild it won't have the same vin as the car the vin boss is ether blank or marked with xxxxxxx. There were a few "soft blocks" in the 72 year but these tended to have the head bolt holes crack or the bolt just to pull out, BMW would not replace these blocks with out return of the defective blocks

[mike472]

Marty,

 

Now that you mention it I remember that story about the rings. I have to go check the block number again to see if it matches the car. I could be wrong. Thanks for reminding me. Damned guest workers!

Mike 

 

 

[mike472]

I decided to start a restoration on my Inka car to keep the car from going off the deep end of rust repair. Here’s the wash down part. Helps to have a fork truck and a good pair of Dollie’s to roll the car around. Marine cleaning in these shots. More to come

[mike472]

Here are a couple of shots of the work I’ve been doing over the last couple months. I have DeVille Autobody doing the job again and it’s looking good. Just test fitting everything up front. I’ve pretty much rebuilt all the sub-assembly’s and have some more work to do dying my door panels and other interior parts. The seats are sitting on the couch in my office slowly being broken in. Got them from Classic Touring Seats.