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Video/Audio of stock M30 motor at Idle?
Posted: Mon Aug 17, 2020 11:01 am
by canada karl
Dose anyone have a video? I'd like to hear how much valve clutter is normal for these motors.
Re: Video/Audio of stock M30 motor at Idle?
Posted: Mon Aug 17, 2020 12:24 pm
by tlake
canada karl wrote: Mon Aug 17, 2020 11:01 am
Dose anyone have a video? I'd like to hear how much valve clutter is normal for these motors.
This is a stock standard 2.8L Euro motor with the 4A1 carb.
1977 528 4 speed
Re: Video/Audio of stock M30 motor at Idle?
Posted: Mon Aug 17, 2020 5:59 pm
by canada karl
Nice ride. Makes me miss my 5 speed. Current E12 is an Auto. I think i do need to adjust my valves. Is that a stock exhaust set up?
Re: Video/Audio of stock M30 motor at Idle?
Posted: Wed Aug 19, 2020 11:57 am
by tlake
canada karl wrote: Mon Aug 17, 2020 5:59 pm
Nice ride. Makes me miss my 5 speed. Current E12 is an Auto. I think i do need to adjust my valves. Is that a stock exhaust set up?
Yes, apart from the downpipes it is stock. Of course, this car has no pollution controls at all, and a 9.0:1 comp ratio. Like most Euro e12s of the time, except the early 518s, it needed 98 octane gas. Up to the fuel crisis you could buy 100 octane gas, that's what the English Rover V8s used.
Re: Video/Audio of stock M30 motor at Idle?
Posted: Wed Aug 19, 2020 3:00 pm
by canada karl
I removed the polution stuff from my 530i as that was apparently responsible for the cyl head cracking issues. Did only the Euro E12's have the 9.0:1 comp ratio? Do you think your car would perform better or basically the same with the fuel injection?
Re: Video/Audio of stock M30 motor at Idle?
Posted: Thu Aug 20, 2020 12:26 pm
by tlake
canada karl wrote: Wed Aug 19, 2020 3:00 pm
I removed the polution stuff from my 530i as that was apparently responsible for the cyl head cracking issues. Did only the Euro E12's have the 9.0:1 comp ratio? Do you think your car would perform better or basically the same with the fuel injection?
All the Euro M30 2.8L motors had 9.0:1, until 1980 model year when they got bumped up to 9.3:1 to get better fuel consumption.
The change to fuel injection was because of emissions, even in Europe the carb cars were having to run lean idle mixtures to pass, which was affecting driveability. The power boost from the 170 hp Euro 1977 528 to the 177 hp 1978 528i was purely down to the sportier cam profile, not due to fuel injection.
The highest compression ratio BMW used pre Motronic was 9.5:1 on the Euro spec BMW 2002tii and 3.0Si (1972-75). The latter used Bosch D-jet injection.