Firstfives.org

I have a 1980 528i motor and a 1977 530i motor.

I am trying to look up some specifications on each motor to help me decide if there are any advantages of running one over the other.

They both have about 150k on them.

The 1980 528i was a BMW replacement motor. It feels strong, but that may be due to the 5 speed transmission that let's me keep it in the power band.

They both seem to have an appetite for oil.

Where can I find specifications on these motors?

This is not really thorough:

http://en.wikipedia.org/wiki/BMW_E12

This link tells me a little more:

http://www.globalcar.com/datasheet/BMW/ ... W_528i.htm

-528i has 9.3:1 compression ratio (181 bhp, 177 lbft)
-530i has 9.0:1 compression ratio (177 bph, 188 lbft)

I plan to use the injection, emissions and ignition systems from the 1980.

Those spec's are wrong for US cars, we got lower compression. 530's were overrated IMO, at 176HP with 8.3:1 CR. 528's were quicker but due in part to better engine management even though they were only rated at 169HP due to a 8.2:1 CR. I have never gotten around to finishing it, but more spec's are below, though I seem to lose a lot of the formatting so it's hard to read. More than you ever wanted to know about M30s.


Engines
HP RPM Torq. RPM Bore Stroke C/R
530i 176* 5500 188 4500 89 80 8.3*
528i 169 5500 166 4500 86 80 8.2

Other M30's, US spec cars
2500 150 6000 155 3700 86 71.6 9.0
2800 170 6000 174 3700 86 80 9.0
3.0 carb 170 5800 188 3700 89 80 8.3
3.3, 78/79 173 5500 192 4000 89 86 8.0
3.3 80/81 174 5200 184 4200 89 86 8.0
3.3 82-84 181 6000 195 4200 89 86 8.8
3.5 85-88 182 5400 214 4000 92 86 8.0
3.5 88-93 211 5700 225 4000 92 86 9.0

Euro M30's
3.0 carb 180 6000 188 3700 89 80 9.0
3.0 D-jet 195 5500 200 4300 89 80 9.5
3.0 L-jet 190 5500 188 3500 89 80 9.0
3.3 carb, 3299cc
190 5500 217 3500 89 88.4 9.0
3.3i 200 5500 210 4250 89 86 9.0
2.8i to 81 177 5800 86 80 9.0
2.8i 82 on 184 86 80 9.3
3.5, thru 82 218 93.4 84 9.3
3.5, 83-87 218 92 86 10.0
3.5, w cat 185 92 86 8.0

Turbos
M102, 3.3 252 89 86 7.0
M106, 3.5 252 5200 279 2200 92 86 8.0

M88/S38
E28 euro 3.5 286 6500 251 4500 93.4 84 10.5
E28 US 3.5 256 6500 243 4500 93.4 84 9.8
E34 euro 3.8 340 6900 295 4750 94.6 90 10.5
E34 US 3.6 311 6900 265 4750 93.4 86 10.0

These are as "Official" of ratings as I can find. E12 US spec 530i's are a little confusing, my BMW manual lists compression ratio as either 8.1 or 8.3:1 depending on weather Mahle or Kobenschmidt manufactured the pistons, yet listed all other spec's the same. I'm also skeptical of the 176HP rating on the same 530i, given that 528i's were always regarded as quicker, yet rated at only 169HP, also 3.3's of the era were only rated at 173 with the same engine management, though a slightly lower compression ratio of 8.0:1, or 174HP with the later Lambda FI. Something doesn't make sense there. The magazines raved about the increase in power when early E24's went from 3.0 to 3.3, yet they were rated at lower power?

There is also some confusion about 3.0 Bavaria's. Some literature lists them at 9:1, but they were rated at the same power as 2800 Bav's with 9:1 compression. Even more confusing is 2800 Bav's were actually rated at 192HP, but that was a SAE gross number, DIN on the euro engines was 170, and BMW kind of made a point about power being "unchanged" when they went from 2.8 to 3.0 and listed the 3.0 carb Bavaria at 170.

I've also seen as assortment of different ratings for euro 3.3's, seeming to depend of what car it came in perhaps. 190, 194, 197 and 200.

High compression euro 3.5's were rated the same early and late at 218, but the late one had significantly higher compression though missing 23CC's, but the early one is the "L" block that is regarded as ultra desirable. Makes no sense to me, but I haven't driven one of the early ones either. Starting in about 85 there was a "green" euro 3.5 with a cat that was basically a US spec smog engine, although rated at a miniscule 3HP more. Getting into the very late M30B35 engines that came in E32/E34's, even though it was a "World" engine, with common spec's everywhere, there is some talk that there was a slightly higher compression version with an added 2 or 4 Horsepower more. That's a "maybe," don't take it as fact, just as a possibility.

Mike:

Thank you for taking the time to answer my question. It is interesting to read the spec's that you list.

The euro motor numbers sure look appealing. I guess I did not realize how low the compression ratio is on my motors. I suppose that there is no need to run the higher octane fuels.

Interestingly, you point out that the 528 has the reputation of being quicker.

That leads me to wonder if my 530 with the 528 management system would do even better?

Are the heads different?

Sorry for all of the questions....I am trying to learn as much as I can.

Blaise wrote:Mike:



Interestingly, you point out that the 528 has the reputation of being quicker.

That leads me to wonder if my 530 with the 528 management system would do even better?

Could be, but not by much. Slightly larger engine with infinitesimally higher compression. Longer duration cam but with less lift.

Are the heads different?

Outside of the different cam the head is the same. Same valves, same ports, same same.

Quick question;

How can one tell what the ratio of a differential is? Are they labelled?

I am curious to know if my 1980 528i has the same differential as my 1977 530i.

In case you could not tell, I am trying to make a plan as to what will be swapped into my 1977.

Blaise wrote:Quick question;

How can one tell what the ratio of a differential is? Are they labelled?

I am curious to know if my 1980 528i has the same differential as my 1977 530i.

In case you could not tell, I am trying to make a plan as to what will be swapped into my 1977.

It should be a 3.45 on both. 75/76 530s had 3.64, but later 530s and all 528s had 3.45. The ratio is stamped on the side of the diff, but by number of teeth, not the ratio. I don't remember which number comes first, the ring or the pinion, but it would be something like 38/11.

[quote="Mike W."

It should be a 3.45 on both. 75/76 530s had 3.64, but later 530s and all 528s had 3.45. The ratio is stamped on the side of the diff, but by number of teeth, not the ratio. I don't remember which number comes first, the ring or the pinion, but it would be something like 38/11.[/quote]

My 1977 had 1976 struts on it...so I will see about the diff.

Blaise wrote:My 1977 had 1976 struts on it...so I will see about the diff.

Even with these 1976 struts, but on '77 model, as Mike have said - the ratio is 3.45.
The stamped numbers are really 38/11. On the old LSD models there is a white paint mark on the housing "S" - for German "Sperre". If you are not sure - check the both differentials for limited slip. Maybe you'll have some luck... I wish you have it.