how do u tell e12/e28?

Whats that bit about shutting the fuel above 1200 RPM when you have your foot off the gas in that article?

When they say 'shuts the fuel supply', I take it it just means the throttle is as closed as much as possible.... which is what would normally happen? or am I wrong.

What is the difference in economy between the two cars (E12/E24 based 6) - I would say engines, but 5's 6's and 7's all have different weights, and thus fuel economies.

Drew21 wrote: good article Ivan, but it doesn't say when the various changes took place. .....it doesn't say whether all of these changes were introduced at the same time or seperately.

2nd paragraph: "similarly updated 635 and 628CSi coupes...began to appear in ....showrooms last month....."

 

That means June 1982.

Edited by Horsetan

good article Ivan, but it doesn't say when the various changes took place. It says that the new engine is smaller capacity and higher compression and has digitally controlled injection and ignition (motronic) but it doesn't say whether all of these changes were introduced at the same time or seperately.

 

 

Jimbob wrote: Don't mean to contradict, coz I know you know your stuff, but my '81 635 with the 3453cc block has the '3.2/3.5' marked inlet manifold. Did I miss read your post?

Not at all. My 635CSi - RUT377W - (the same colour
as yours) had the bunch of bananas inlet manifold
and Motronic. So did an X plate 732i I had a couple of
years ago
Early Motronic M30's such as the 732i have this
arrangement. It may be that BMW started using the
later 745i manifolds as standard from mid 1981
when the E28 came out. I've never seen an E28 with
the old manifold.

Jimbob is right; my parts car ('81) has the one-piece manifold too; all motronic M30s have this type so far as I know and 6ers went motronic in 1980, with the original engine size. Ivan seems sure that the smaller engine came in may '82 but I have yet to see any evidence of this; there is little external difference between the E12 motronic lump and the E28 version that followed it.

cheers

 

The 3430cc unit came out with the May 1982 E28
based E24, not before. It's really a long stroke
version of the 3.2 engine with it's smaller bores. It
was designed to get around the old 3453cc engine's
appetite for head gaskets. The one piece manifold
with '3.2/3.5' is from the 745i Turbo and was first
used on a Euro M30 with the 3430 motor, same part.

But being BMW, nothing is THAT simple..........South
African built E23's had the one piece inlet manifold in
mid 1981.

Early Alpina B9 3.5 cars up to mid 1983 also have
the old 3453cc engine.

Brucey wrote: ... I don't know when they changed over to the 3430cc type.....

May 1982

on the subject, my car is a late E12 based 1982 car and has the 3.2/3.5 manifold casting and motronic engine mangement, though with an auxillairy air valve rather than the idle stabilisation unit of the later motronic systems.

Does this make it a 3430 or a 3453 engine? and what is the engine code for my engine, the B34/ B35 number? I'm looking for a new cam and am trying to work out what will be compatible. Extra info: on the dizzy, the leads all come out of the side rather than the earlier circular pattern of HT leads with the king lead in the centre.

thanks

for telling an E12 car I would look mostly at the interior as here the difference is very marked in the door cards, the heater controls and the clocks unit.

BMW's ETK lists the changeover as 5/82 between E12 and E28-base cars. I daresay there are a few oddballs out  there, maybe they had to use up a few bits and pieces, but a 7/82 build date car should be an E28 base without doubt.

cheers

 

Why don't you post a couple of pics, and then you can end this debate accurately.