E34 520 engine conversion

[thomask]

Dear all si-fus,I’m quite new here and I’ve been trying to look for a good E34 520 24V manual version, but so far couldn’t find one. Therefore, I’m thinking to buy a cheap 12V manual version and convert to 24V (maybe the venos version). Being very new in BMW and car modification, I would like to seek your advice in the following items:1. What are the components involved in this type of engine modification?2. Where to find a good BMW engine and mechanic?3. What is the price range for this type of conversion?Any of the si-fus done this before? Is it worth it? Is it advisable to do so? Really appreciate allll si-fus advices….

 

[Lionel_Koh]

Originally posted by thomask@Apr 28 2005, 02:42 AM
Dear all si-fus,

I’m quite new here and I’ve been trying to look for a good E34 520 24V manual version, but so far couldn’t find one. Therefore, I’m thinking to buy a cheap 12V manual version and convert to 24V (maybe the venos version). Being very new in BMW and car modification, I would like to seek your advice in the following items:

1. What are the components involved in this type of engine modification?
2. Where to find a good BMW engine and mechanic?
3. What is the price range for this type of conversion?

Any of the si-fus done this before? Is it worth it? Is it advisable to do so? Really appreciate allll si-fus advices….

My opinion is get a cheap 520,12V 89-90 around 15-25K.......seach for M50b25 halfcut and convert it.......less headache.........right zoggee ko ko? :nyehehe:

 

[Ghostrider-SG]

Originally posted by thomask@Apr 28 2005, 03:42 PM
Dear all si-fus,

I’m quite new here and I’ve been trying to look for a good E34 520 24V manual version, but so far couldn’t find one. Therefore, I’m thinking to buy a cheap 12V manual version and convert to 24V (maybe the venos version). Being very new in BMW and car modification, I would like to seek your advice in the following items:

1. What are the components involved in this type of engine modification?
2. Where to find a good BMW engine and mechanic?
3. What is the price range for this type of conversion?

Any of the si-fus done this before? Is it worth it? Is it advisable to do so? Really appreciate allll si-fus advices….

Not sifu....just share info.

From M20 convert to a M50 can. Just be sure that your transplant is from a halfcut. You need all the wiring and harness....ECU....gearbox and driveshaft.

If you get the engine only, whoever doing the conversion for you will have a almost impossible task.

If you insist that you want a manual....lagi jialat....cos most halfcuts are automatic. I dun think the manual can be just swap like dat. This you better check with those stick shift brothers.

If you are keen to do your engine conversion....I think over at Johor...it can be done for around RM10K odd. Remember to ensure that the workshop knows what they are doing.

I dun know if posting workshops names is a taboo subject here or not....I know someone doing conversion in JB if you are keen. Drop me a PM and I can share with you.

 

[MeanStreak]

Originally posted by Ghostrider-SG@Apr 28 2005, 05:07 PM

If you get the engine only, whoever doing the conversion for you will have a almost impossible task.

If you insist that you want a manual....lagi jialat....cos most halfcuts are automatic. I dun think the manual can be just swap like dat. This you better check with those stick shift brothers.

I think you can't swap a manual tranny from a 12v to a 24v engine, if thats what it means

 

[teejay]

Originally posted by MTek1318+Apr 28 2005, 06:23 PM-->QUOTE (MTek1318 @ Apr 28 2005, 06:23 PM)

 

[MeanStreak]

Yes TJ, what I meant was its not a direct swap..

 

[thomask]

Hey, thanks for all the advices.

Ghostrider, thanks for your invitation but I’m from KL and I’d prefer to find a mechanic in KL cos it’s easier for me if something wrong after the installation.

Teejay, what about M20 boxes on 24V 520/525 venos engine?

 

[Ghostrider-SG]

Originally posted by thomask@Apr 29 2005, 10:18 AM
Hey, thanks for all the advices.

Ghostrider, thanks for your invitation but I’m from KL and I’d prefer to find a mechanic in KL cos it’s easier for me if something wrong after the installation.

Teejay, what about M20 boxes on 24V 520/525 venos engine?

Auto or Manual ?? If its auto...I dun think so....

M20 2.0L box cannot use for the M50...one is a 4 speed and latter a 5 speed.

If you up the engine...you need to strenghten the torque convertor...some pple I know get away with this using a ATF cooler but its not a ideal solution. Best is you get a 2.5L box as the torque convertor is much stronger than the 2.0L ones.

 

[Zoggee]

huh..!!?? :blink: now I'm confused..!!! what is the subject again...M20 or M50 slush box or stick..?? :blink:

 

[Lionel_Koh]

Originally posted by Zoggee@Apr 29 2005, 05:12 AM
huh..!!?? :blink: now I'm confused..!!! what is the subject again...M20 or M50 slush box or stick..?? :blink:

Ko Ko...the topic is "engine convertion" but some ppl off topic sikiiiiiiiiitlah h34r: h34r: ????????

 

[ehoe]

Just curious too, got a friend whom wants to convert his M20B20 to a M20B25 and his mechanic told him that he can reuse back the existing DME/ECU of the M20B20 for the M20B25. Apparently the DME on the 2.0/2.5 are more of less the same. And since the 2.5 shares almost all identical parts (i.e AFM, alternator, etc,etc) as the 2.0, it is not required to buy a full half cut. Just then 2.5 engine will do so its a little cheaper.

He even went as far to say that the current SuperChip that is being used in the M20B20 DME can be also reused for the 2.5 after the conversion. I'm a little curious, wouldn't the 2.5 use different fuel/air mappings, etc and as such require the 2.5 DME?. Not being so electronically inclined myself but common sense would dictate that the 2.0 DME may not be the optimal DME for a 2.5. Any of the sifu's out there care to verify on this?.

What are the pro's & con's of using the 2.0 DME on a 2.5?. Hope someone can explain in mode detail..... thanks.

 

[Lionel_Koh]

Just to share what i know ...correct me if i'm wrong....U can use back the m20b20 ECU after the convertion....but u won't get the max hp for m20b25 that u converted...Exp...M20b25 shld give u around 168hp....but u use back the m20b20 ECU, the hp u get is less than 168hp cos the ECU can't perform max.......

 

[ALBundy]

Firstly, to perform the conversion as per originally asked by Thomas, many has done it. The cheapest and easiest way as many have suggested, get a half cut, market price now ranges from 6500 to 9000. After the conversion, then you can proceed to the tranny conversion. You have to find the flywheel, manual tranny, clutch set, pedal set (hopefully come with the slave pump, clutch pump, oil reservoir and etc), long shaft (hard to find and in most cases, cut and re-welded), rear diff (which should be available easily since manual and auto both uses 3.23 ratios), gear knob and etc.

As for the M20B20, there are 2 different ECUs employed, one is 172 and the other 173. The 173 is used by both M20B20 and M20B25.

Rgds

 

[ehoe]

Originally posted by ALBundy@Jul 11 2005, 09:18 AM

As for the M20B20, there are 2 different ECUs employed, one is 172 and the other 173. The 173 is used by both M20B20 and M20B25.

Rgds

So if the ECU is the 173 model does that mean the converted M20B25 engine will perform at optimal/max hp?. So how do you tell which model of the ECU is in use?. How to identify the ECU model, got a label or serial number or something ah. :blink:

 

[ALBundy]

Yeah, the serial number of the motronic ECU is printed on the ECU. 173 is used on the M20B25 but some M20B20 has them as well (most of the time, imported units I was told). I have seen one on my mechanic's e34 520i 12V...one day a scruplous customer swapped it when he was not around with a 172 and he complained about the lack in power now!!

 

[ehoe]

Originally posted by ALBundy@Jul 11 2005, 10:29 AM
Yeah, the serial number of the motronic ECU is printed on the ECU. 173 is used on the M20B25 but some M20B20 has them as well (most of the time, imported units I was told). I have seen one on my mechanic's e34 520i 12V...one day a scruplous customer swapped it when he was not around with a 172 and he complained about the lack in power now!!

Just curious, if the ECU 173 can be used on both the M20B20 and M20B25 and is supposedly optimised for max HP on both engines, does that mean its an intelligent ECU that knows which engine its plugged into?.

Common sense would think that a 2.0 & 2.5 engine will use different fuel/air mappings, larger injectors, higher pressure fuel pump, etc. So that would mean the ECU 173 is intelligent enough to know which settings to use in the 2.0 or 2.5 engine. hmm....so canggih one meh the ECU?.

How abt using the ECU 172 on a 2.5? If the ECU follows the 2.0 fuel/air mappings, etc wouldn't the engine be running lean or something?. Very curious.

 

[ALBundy]

The 172 only used for M20B20. I supposed if you use the 173 on the 2 liter engine, you would be running a little rich which should give you better low end torque and no harm done to the engine other than spending a few extra dollars on gas.

 

[Lionel_Koh]

Thanks albuny for the explaination.....Another question here...What the different if use back the M20b20 throttle body n monifold when convert to M20b25? If i'm not wrong..the M20b25 throttle body n monifold are bigger.....Any idea???

 

[Lionel_Koh]

All sifus still not wake up? Albuny...where are u....

 

[ALBundy]

If use smaller manifold and air flow meter, you will get better low end torque (translated into everyday language means better pick up) but sacrifice some mid to top end power. Anyway, M20 stuff veli cheap and who knows the Puchong pimp king may have some spares in his junkyard hehehe h34r: h34r: