1980 Euro 728i

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canada karl
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Joined: Tue Jan 06, 2009 3:50 pm

1980 Euro 728i

Post by canada karl »

Is there any difference between the M30 motor
in this model and the one in a 530i? Do they have the same ECU?
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
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Mike W.
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Re: 1980 Euro 728i

Post by Mike W. »

A Euro 728 would have a higher compression 2.8 engine, probably 9:1 instead of the 8.3:1 of a US spec 530i. About the same power but a touch less torque. The euro car might have a hotter cam and would have a different curve on the distributor, and of course would not have come with all the smog equipment that was on US cars. Different ECU, but I bet you could interchange them and they'd run just fine. Very similar engines, but not exactly the same.
Mike W.



02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
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tlake
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Joined: Wed Feb 03, 2010 6:33 pm
Location: WA

Re: 1980 Euro 728i

Post by tlake »

Mike W. wrote: Sun Oct 23, 2022 12:41 pm A Euro 728 would have a higher compression 2.8 engine, probably 9:1 instead of the 8.3:1 of a US spec 530i. About the same power but a touch less torque. The euro car might have a hotter cam and would have a different curve on the distributor, and of course would not have come with all the smog equipment that was on US cars. Different ECU, but I bet you could interchange them and they'd run just fine. Very similar engines, but not exactly the same.
For 1980 model year in Europe the e23 7 series went completely fuel injected. in 1977-79 they had the single carb 728 & 730, and the injected 733i (3.2L). For 1980 it was 728i, 732i, 735i & 745i.

Euro 1980 528i/628CSi & 728i all used a 184 hp M302.8 with 9.3:1 comp ratio. The earlier Euro carb engines were 9.0:1. The higher comp ratio, and weight cutting program (thinner glass, hoses, panels etc) was all to boost fuel efficiency in the wake of the 2nd fuel crisis. Tachs even had a green segment, in the lead up to the pending swinging fuel economy meter needle. 8)
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