Hey yall,Just need your opinion regarding M40B18 and M20B20 engine. Which of these 2 is...1. more reliable?2. cheaper to upgrade or mod?3. Any piggy back ecu or performance chip recommended?Btw, i'm not a topspeed kind a guy. Just need a car with more power in low rpm so I can get fast, faster.Not willing to go for any engine above 2000cc also.Danke.
M40B18 vs M20B20
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fabianyee
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The M40 would be cheaper to maintain and seemingly a bit more reliable.
However, these 2 engines pale if u throw in another wonderful BMW engine, the M42B18.. Ths engine used for the E30 318is and E36 318is.
Reliable engine.
Duplex timing chain.
140hp (vs 115hp for M40B18 and 129hp for M20B20 motronic)
More mod possibility.
However, these 2 engines pale if u throw in another wonderful BMW engine, the M42B18.. Ths engine used for the E30 318is and E36 318is.
Reliable engine.
Duplex timing chain.
140hp (vs 115hp for M40B18 and 129hp for M20B20 motronic)
More mod possibility.
ALBundy
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Yeah, the M40 engine is cheaper to run with better fuel mileage than the M20B20. In my honest opinion, no point modding these two engines, upside potential is rather limited. Best mod is an engine transplant.The M42 is a great engine, wonder why BMW doesnt make such 4 pot engines anymore. Rev it pass 5000 rpm and you will know you are driving an honest to god BMW. Stock Rev limit is close 7000rpm, and it comes with variable intake length (DISA) with forged crankshafts and con rods, timing chain and individual coils.
kevster30
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1. more reliable?
- Both engines are reliable but it all depends on the general condition of the engine
-the M40 is prone to premature camshaft and lifter failure, the M20 is prone to vacumn leaks, oil leaks and wiring related issues.
- the M40 is more fuel efficient, the M20B20 drinks as much if not more than the M20B25.
2. cheaper to upgrade or mod?
- There is no such thing as cheap mods. However that being said it is easier to obtain mod items for the M20.
3. Any piggy back ecu or performance chip recommended?
- only go down this road with an intrinsic knowledge that your fuel consumption and reliability will suffer.
Agree with the earlier comments, neither engine will yield comensurate returns when modded. How do I know? I hv owned both.
In conclusion, if these two engines meet with your personal criteria, My vote would go towards the M20B20, it provides better drivability, but do try to source the motronic version. Then look for the throttle body and intake manifold frm the M20B25 and bolt it on. Also consider replacing the ECU with the one frm the M20B25. Remember, these only work on the Bosch MOTRONIC engine managment systems.
Hope this helps.
- Both engines are reliable but it all depends on the general condition of the engine
-the M40 is prone to premature camshaft and lifter failure, the M20 is prone to vacumn leaks, oil leaks and wiring related issues.
- the M40 is more fuel efficient, the M20B20 drinks as much if not more than the M20B25.
2. cheaper to upgrade or mod?
- There is no such thing as cheap mods. However that being said it is easier to obtain mod items for the M20.
3. Any piggy back ecu or performance chip recommended?
- only go down this road with an intrinsic knowledge that your fuel consumption and reliability will suffer.
Agree with the earlier comments, neither engine will yield comensurate returns when modded. How do I know? I hv owned both.
In conclusion, if these two engines meet with your personal criteria, My vote would go towards the M20B20, it provides better drivability, but do try to source the motronic version. Then look for the throttle body and intake manifold frm the M20B25 and bolt it on. Also consider replacing the ECU with the one frm the M20B25. Remember, these only work on the Bosch MOTRONIC engine managment systems.
Hope this helps.
fabianyee
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There are a few M42B18s running around...et5 said:
The M42B18 has a more advance TB with 2 butterflies. The M42B18 from the E36 has a 3rd butterfly to provide better low and mid range torque and opens up at 5000rpm for higher flow.
metalrizca
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kevster30 said:
1. throttle body..
2. intake manifold..
3. ecu..
what happen next..?
looks interesting..
tell me sifu..
racun me more,
pliz..
kevster30
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metalrizca said:1. throttle body..
2. intake manifold..
3. ecu..
what happen next..?
looks interesting..
tell me sifu..
racun me more,
pliz..
What happens next is a nice set of extractors and get ready to fuel up frequently at ur local gas station. Also beg, borrow or steal a LSD as you now need to lay down the power effectively........ekekekeke
kevster30
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et5 said:TQ Sifu for enlightenment.. wonder if any body dropped it in a local E30? Guess most ppl would prefer choosing a M20B25 for the performance rush
There are at least 3 members here who have successfully plonked a M42B18 into late model 4-door E30s. They rock! Power to weight ratio is impressive, consumption is the same with the replaced M40B18, and YES.....it is a lot of fun and the four-pot engine allows for better wieght distribution.
E
elwine30
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well, actually i believe depends what the driver wants.
For driveability and relaxing drive, the M20B25 would be the good option.
For fun, track and yeeehhaaa driving, M42B18 is the one. Baby M3
For driveability and relaxing drive, the M20B25 would be the good option.
For fun, track and yeeehhaaa driving, M42B18 is the one. Baby M3
kevster30
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et5 said:TQ Sifu for feedback
OK can guess that Fabian and Elwine are 2 out of the 3 conversions ..
care to share experiance of the conversion process?
Bro,
I don't mean to be rude but u r effectively trying to hijack this thread. If u would like to learn more about the M42 and the transplant procedure, pls start a new thread. It is unfair fot the starter of this thread.
Cheers.
zaskar
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popgun, actually there has been quite extensive discussion betewen the pro's and con's of the m42b18 vs the m20b25 for e30's in the states. Worth having a look if u have e time.
But bottom line, if in the country where bigger is better (big CC's rule) for them to actually consider a 1.8ltr engine tells u something about how highly they rate the m42.
But bottom line, if in the country where bigger is better (big CC's rule) for them to actually consider a 1.8ltr engine tells u something about how highly they rate the m42.
teejay
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my thoughts....
you won't get much performance out of the m20b20, cause power to weight ratio isn't too great
reliability however should be better then the m40/42
for low end torque, just use a short ratio , i.e 4.45 or something
basically you want a car with character, drivebility etc.
i'm guessing you would be itchy to upgrade once you settle in, power is never enough......
but it boils down to when will you wanto stop modifiying your car, as both engines has its limits ,pros ,cons and we will probably go on till we are grand-dads before we could finish......
you won't get much performance out of the m20b20, cause power to weight ratio isn't too great
reliability however should be better then the m40/42
for low end torque, just use a short ratio , i.e 4.45 or something
basically you want a car with character, drivebility etc.
i'm guessing you would be itchy to upgrade once you settle in, power is never enough......
but it boils down to when will you wanto stop modifiying your car, as both engines has its limits ,pros ,cons and we will probably go on till we are grand-dads before we could finish......
