Early 325i engine help needed !

[Gav1234]

Hi , new on here , have a few questions I could do with some advice on with my new project car .

I recently pick up a 1986 325i 3 door chrome bumper in zinnobar red . It's sat in a barn for ten years , has a really clean straight body and has only covered 75k with a well documented service history .

Unfortunately the blessing that is dry storage that has preserved the body so well has also , due to previous mechanical issue ruined the engine .
It appears to have been left with moisture in the barrels so the walls of the cylinders are rotted out and so is the cylinder head .
It seems to me and my mechanic that the engine is scrap .

Questions are , what is the better block to use , the older high comp or the std comp later type ?

Which head is the better one to use ? Are any of them stronger than others as head failure seems quite common . Is that the reason that bmw dropped the high comp ratio ?

If my car runs the older Bosch motronic 1.0 is it worth updating to the later 1.3 type while it's all in bits ? If so is it worth installer the later style m20 engine along with it ?

Would installing a later type engine and management de-value the car in the eyes of a enthusiast ?

I'm definitely into keeping this car as I recently restored a 316 e30 4 door and love driving it .
Rather than pulling the 325 straight into the workshop and doing a complete resto I'd like to get all the mechanicals ironed out first , get it running right driving nice and handling propperly before we strip it out to repaint it all .

I have been up for hrs trying to read as much as possible as I'm not from a Bmw background , so I do apologize if these are old well documented questions , any help will be much appreciated

Cheers

[HairyScreech]

No difference to the blocks.

All 885 heads are nearly identical.

The CR was dropped for the US market and markets with poor fuel, they dropped it across the range rather than make 2 versions.

Yes the engine management upgrade is a huge improvement.

99% of people would not be able to tell the difference between the two engines as the only difference is the pistons.
An early engine with late management looks nearly identical to a late engine.
It would only reduce the value if E30s start to get like american muscle cars were they obsess about matching numbers

Your best option is to build a 2.8 with a fresh block from the high comp lump and use the late management.
You will have to pull the engine apart to check everything and replace the block anyway so you may as well do something that is considered an "accepted" modification while you are in there.

Edit - just to clarify, get a new block, an m52b28 early crankshaft and some M20B20 rods and use all the other parts of the high comp engine you have now.

[pacerpete]

Unlike many here, your car has the potential to be worth quite a bit more than you will inevitably spend on it ! To maximize that potential, you need to keep it ORIGINAL ! There is nothing wrong with a good pre facelift 325 and they are faster than a facelift car, even with their 'prehistoric' engine management !

This is the answer to your problem !

http://www.ebay.co.uk/itm/BMW-325-prefa ... 1873651216?


You may buy a cheaper engine, you will not buy a better one !

I also have an excellent pre facelift hi comp bottom end if you wish to build a good engine utilising bits of yours.

[Mitchen]

Sounds like Gavs got a good'un.. any pics?

[daimlerman]

What I want to know is this the rarest of the rare 3 door chromes.......

Rare these three door cars.They were only built on Friday afternoons.This is because they had to wait until the Quality Control Inspector finished for the weekend.

Is the OP's car one with two doors on the n/s,or the ultra rare version with two doors on the o/s?



If originality is not top of the OP's wish list,then fitting an M50/52 from a cosmeticly challenged E34/36 is worth thinking about.

[Gav1234]

Hi all , thanks for the replies , really helpful many thanks .

On closer inspection , the block bores are toast , the pitting is really really deep .
The head is also wasted as the rot has eaten through from the combustion chamber or squish band whatever you prefer to call it through to the water jacket .

I would love to build a 2.7 or 2.8 but my finances and plans for this car at the present time do not allow me to go that far with it unfortunately !
I am also restricted by time as I'll need another car that i can use on the weekends sooner rathern than later .
I have my trusty 316 that I'll have to sell to finance all of this , which is my current weekend car .

The upgrade in injection system seems to be universally agreed as a worhthy upgrade from what I currently have so that is something I shall do .

I'm assuming to do so I will need the later style engine as from what I can fathom the dizzy , inlet , loom , ECU and sensors are slightly different .

So can I use the hi compression pistons (provided they are serviceable) in a later engine , with the uprated injection system and be assured nothing will meet in the middle ? As I'm guessing the higher compression is achieved by a domed piston ?

I'll happily post some pics up , is it easier to do that via Tapatalk or another app as all the pics are on my phone ??

Thanks again , hope I can be of help at some point in the future