Engine conversions and 'need more power' information thread
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    Engine conversions and 'need more power' information thread

    This topic has been discussed on many occasions which is why a "Sticky Thread" has been created.

    An engine conversion is often the Best Value For Money when trying to squeeze more hp under the bonnet of your BMW..

    What engines produce good horsepower???

    Here are figures for the E36 3 Series to give you an idea of power increases.


    316i 1990-98 102
    318i 1990-98 115
    318is 1991-95 140
    318tds 1995-98 90
    318ti 1994-96 140
    320i 1990-96 150
    323i 1994-98 170
    325i 1990-94 192
    325td 1993-98 115
    325tds 1993-98 143
    328i 1994-98 193
    M3 1992-95 286
    M3 EVO 1995-98 321

    What parts are required?

    There are factors to consider when choosing a replacement engine.

    Firstly you need to know if the car you have and the engine you have chosen has EWS.

    What is EWS?

    See the attached document here...... Attachment 50
    If your EWS systems match then the parts you require to get the engine working will be:-

    Complete engine

    Engine loom


    If your car is EWSII you will need additional parts:-

    As well as those listed above you will need... Transponder key, ignition barrell and EWS module. Your car will normally have EWS is it is a 1996 Y.O.M (year of manufacture) or later..

    Other considerations:-

    When increasing the cars performance you should consider the uprating of:-

    Braking System


    Prop, Differential, Drive Shafts, Bushes and Engine Mounts.

    What if the EWS systems are different?

    This is a common mistake.

    I performed an engine conversion on my own 1992 318is 16v Coupe.

    I replaced the engine with an EWSII 1995 3.0 24v Motorsport engine.

    Here are the parts I had to replace to overcome the problem...

    Complete Engine
    Engine Loom
    Complete Car Loom
    EWS Module
    Transponder Key
    Transponder Ring
    Ignition Barrell
    EWS Transmitter
    Steering Column
    Brake, Discs, Pads, Calipers and Hubs.
    Suspension (318is struts pushed the front wheels too far towards the front bumper)
    Diff Housing
    Engine Mounts
    Chassis Reinforcing plates for Gearbox and Diff housing
    Exhaust Manifold
    Exhaust System
    Drive Shafts
    Suspension Bushes

    When replacing a 4 cylinder engine with a 6 cylinder you will also need to replace the instrument cluster.

    Where can I obtain the parts I require?

    LK Spares new recon used BMW car parts, BMW Breakers, BMW Dismantlers, BMW Servicing

    These Breakers were not listed in any particular order... Contact them all to get the best qoutation

    What do I need to consider?

    Most importantly........... COST!!!

    Is it cheaper to buy a more powerful car?

    When I was asking for information on my conversion on other less informative forums I was disgusted to hear "Just go and buy an M3"

    They were missing the point, my car was already completely modified. It had been featured by PBMW magazine and Redline magazine and was just in need of extra hp!

    There was no way I was going to consider selling my pride and joy that I'd spent many thousands on just to buy a bog standard M3 and have to do it all again.

    I'm sooooo glad I found the parts donor car (a damaged E36 M3) for £1800. The problem was that a parts donor doesn't give you all the parts you need and causes further costs.

    My car has cost me thousands of pounds more than it's value but i'm happy. It's unique and to me that's what modifying is all about.

    Yes... I could have Turbo'd or Supercharged my original engine but it would have cost me thousands more and probably still wouldn't get near to the 286 normally aspirated horses that I have galloping under the hood!

    I hope this helps you guys (and girls) and I certainly hope it reduces the number of questions we have regarding this conversion..

    PS Information is available on how to get around the EWS system but it will not be posted willy nilly for all to see. It will be disclosed to only those that are in Dire Straits AND genuine modifiers

    But I don't want to go to the trouble of an engine swap! What other modifications are possible?

    There are a variety of modifications that can performed on your existing engine in order to gain extra BHP and torque. But when you are starting out with an NA (naturally aspirated) engine (e.g. non turbo) the gains are minimal in real world terms.

    Modifications Include:-

    Air filter replacements and Induction kits (the merits of these are dubious and we would not advise removal of your stock BMW airbox or filter...as performance can and does suffer)

    Performance Exhausts - Always a good option

    ECU chips/remaps - if done by the right person/company, a very good option for more power.See the ECU forum for more detailed info.

    Supercharger/Turbo's - See the relevant subsections for these conversions. But beware, they are EXPENSIVE and for a lot of BMWs a lot of custom fabrication and parts making is needed, hence the high cost.

    Electric superchargers and 'power valves' - ONLY mentioned here to warn you NOT to buy or fit these complete junk items.

    The BMW is very well catered for by aftermarket manufacturers. The problem being that the gains expected and the gains acheived are more than often not matched and cost per hp is much lower in many cases to drop a larger sized engine in.

    Beware though, unless an engine swap is declared to your insurers (and the DVLA) you will effectively be driving uninsured and should the worst happen (and you kill or maim someone) you will be in a whole world of pain (and prison). The same goes for some modifications if undeclared.

    Big thanks to RYM for permission to use his thread

  2. The Following User Says Thank You to Ferret For This Useful Post:

    E36 lover (03-04-2012)

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