Hi guys,
Am an avid BMW and E30 fan. This is my first post on here as I need some tech help please.
I have a 1991 318 manual E30 convertible. The engine runs very well and I have never had an problems with it. However, I don't ever plan on selling my E30 so I want a more stronger engine for the long term, especically bearing in mind that my current engine has just done over 150k and is coming to 25 years old.
What engine swap would you all recommend? I want an engine swap that would be as simple as possible, with minimum modifications/fabricating as possible.
I've read a lot about the 1.8is M42 engine. Would that be a straight engine swap with the existing wiring loom and ECU, or would I need other parts as well such as the loom, ECU, gearbox etc?
I know there are tonnes of topic on this, but it becomes overwhelming when trawling through the forums looking for an answer as there are so many posts on this subject.
Would really appreciate any help. Thanks.
Recommendations for engine swap please
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Grrrmachine
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'89 325i Touring | Touring Resto Thread | In-Dash Screen install
The M42 or M20 engines would be the easiest as they were available in the E30, so will be almost plug and play.
Whichever engine you choose, you will need the engine loom and ECU for that engine - your existing loom and ECU will only be good for another M40 engine.
Of the two, you could consider the M42 the easier swap as you can keep your existing gearbox, prop and diff. You would need the complete engine (loom, ECU, AFM), M42 radiator and hoses, engine mounts and complete exhaust including the manifold.
For the M20, you'd need all of the above (for an M20 obviously), but you would also need the M20 gearbox, gear linkage, prop and diff to suit.
For both swaps, there will be some minor differences in the engine bay such as the AFM bracket or coil pack bracket if you went for the M42.
Personally, I'm not sure the rev happy M42 would suit a convertible, I'd prefer to have the 6cyl soundtrack and torque to just cruise around.
Whichever engine you choose, you will need the engine loom and ECU for that engine - your existing loom and ECU will only be good for another M40 engine.
Of the two, you could consider the M42 the easier swap as you can keep your existing gearbox, prop and diff. You would need the complete engine (loom, ECU, AFM), M42 radiator and hoses, engine mounts and complete exhaust including the manifold.
For the M20, you'd need all of the above (for an M20 obviously), but you would also need the M20 gearbox, gear linkage, prop and diff to suit.
For both swaps, there will be some minor differences in the engine bay such as the AFM bracket or coil pack bracket if you went for the M42.
Personally, I'm not sure the rev happy M42 would suit a convertible, I'd prefer to have the 6cyl soundtrack and torque to just cruise around.
James
'91 325i Sport
'93 318i touring 16v
'91 325i Sport
'93 318i touring 16v
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Brianmoooore
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It's true that if you want to get a move on, you have to row an M42 along with the gear stick, but for just cruising along the M42'll do everything that the M40 will, and use considerably less fuel doing so. M20 soundtrack is nice, but it comes at a price at the pumps.jmc330i wrote: Personally, I'm not sure the rev happy M42 would suit a convertible, I'd prefer to have the 6cyl soundtrack and torque to just cruise around.
I'm competent with tools, but have never done an engine swap before and would rather pay a decent technician to do it. I think things like a complete engine swap are left to people who know what they're doing.Phill172 wrote:Are you handy with spanners or are you looking for someone to do it?
Thanks for the input guys, will keep my eyes peeled for a decent M42 318iS engine
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Brianmoooore
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If they know what they're doing, then the old engine will be removed complete with its wiring loom, and similarly, the M42 will go in with loom completely connected to it.
As mechanical jobs on E30s go, an engine swap is fairly easy, as long as you have the equipment to lift heavy objects and to get underneath the car. I'd recommend pulling out the M40 complete with gearbox, and swapping the gearbox to the new engine on the floor. Treat the gearbox to a new oil seal for the selector shaft while its out, and check that the gear linkage isn't worn.
As mechanical jobs on E30s go, an engine swap is fairly easy, as long as you have the equipment to lift heavy objects and to get underneath the car. I'd recommend pulling out the M40 complete with gearbox, and swapping the gearbox to the new engine on the floor. Treat the gearbox to a new oil seal for the selector shaft while its out, and check that the gear linkage isn't worn.
I'd think twice. The M40 1.8 is a good, torquey little engine and whilst the M42 has more power, it's virtually all over 4000 rpm. The engine swap is easy enough - but finding a good one with no issues that's ready to go is less so. I'm not saying it's a bad idea but it may prove to be a lot of money and aggro for little gain.
this sounds a bit like swapping a m50b25 in place of a m20b25 that used to be all the rage. nowadays they use 2.8 and 3.0L engine.
The moral of the story is that unless you add more cubic inches its hardly worth it for a street car.
For this reason the M20 is a better swap, it has its downsides thought its heavier and chews more juice.
otherwise do nothing and enjoy the car and get a better one next time
The moral of the story is that unless you add more cubic inches its hardly worth it for a street car.
For this reason the M20 is a better swap, it has its downsides thought its heavier and chews more juice.
otherwise do nothing and enjoy the car and get a better one next time
E30 325is with M20B31
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jimbom30cab
- Tech 1 freak
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i'd go for a M20B25 with DME 1.3 swap, fairly easy, loads of spares available, cheap and plenty of fun.
you could then always tune it up a bit in the future if you wanted.
you could then always tune it up a bit in the future if you wanted.
My view, if you are going to be paying someone to do the job at least pay for something worthwhile.
I know you will disagree and I know you want to keep your car etc but whats the point in paying someone to do the conversion when the car already exists and you could just sell up and buy it?
If you are not convinced on a M42 then i would look at a M50, power, reliability, fuel consumption, the list goes on. Swapping to a M20 you may aswell flush your money down the toilet in my opinion.
(same for a m42
)
I know you will disagree and I know you want to keep your car etc but whats the point in paying someone to do the conversion when the car already exists and you could just sell up and buy it?
If you are not convinced on a M42 then i would look at a M50, power, reliability, fuel consumption, the list goes on. Swapping to a M20 you may aswell flush your money down the toilet in my opinion.
(same for a m42
)