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.
MODEL YEAR BHP
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...... EWS.pdf
If your EWS systems match then the parts you require to get the engine working will be:-
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..
When increasing the cars performance you should consider the uprating of:-
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 Car Loom
Brake, Discs, Pads, Calipers and Hubs.
Suspension (318is struts pushed the front wheels too far towards the front bumper)
Chassis Reinforcing plates for Gearbox and Diff housing
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?
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.
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.