M52 vs M54 vs N52

UK forum for general and technical discussion about the Z3 roadster
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Blacknight
Joined: Fri 10 Apr, 2015 12:23
Posts: 18

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Location: South Wales

M52 vs M54 vs N52

Post by Blacknight »

I'm just wondering, forget actual power differences, what are the actual differences / benefits v
Between the two engines.

For example, I understand the M54 is fly-by-wire, but is this actually a real world benefit? I remember going to my first fly-by-wire car and the throttle felt rather odd compared to the previous cable operated cars.

Also, are all UK M52 and M54 blocks fundamentally the same? Could a 2.0 block be bored and lined to accept 84mm pistons from a 2.8 or have a crank from another unit installed?
Last edited by Blacknight on Mon 22 Aug, 2016 12:40, edited 1 time in total.
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Southernboy
Joined: Thu 07 Oct, 2010 12:39
Posts: 6436

  Z3 roadster 3.0i
Location: Johannesburg

Re: M52 vs M54

Post by Southernboy »

Some basic info... It would seem the 2.2 block will not accommodate the longer stroke of a 2.8 (75mm vs 84mm)

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NZ00Z3
Joined: Thu 23 Jun, 2016 01:26
Posts: 95

  Z3 roadster 3.0i

Re: M52 vs M54

Post by NZ00Z3 »

The blocks are fundamentally very similar and will take parts for both engines. There are differences.

It starts getting very different when you look at the heads.
- M52, single VANOS, Cooling water fed to the front of the head.
- M52TU (M54 beta test), dual VANOS, Cooling Water fed through to the back of the head and has a completely different flow path through the head and block compared to the M52.
- M54, dual VANOS,Cooling Water fed through to back of head and has same flow path as M52TU.

M54 has different technology sensors for knock, cam position etc.

Things like cams and associated gear are transferable between M52TU and M54.

This covers the basic's. If you are looking at doing a swap of parts between engines, do your home work.
deni2s
Joined: Mon 25 Mar, 2013 22:02
Posts: 761

  Z3 roadster 2.8

Re: M52 vs M54

Post by deni2s »

Maybe I am wrong, but M54 don't like high revs and has more torque at low end as opposite to M52. And for M52 there are more cheap add-on possibilities for increasing power.
peter2b
Joined: Sat 01 Nov, 2014 18:47
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  Z3 roadster 2.2i
Location: cheshire

Re: M52 vs M54

Post by peter2b »

my 2.2 m54 revs very quickly too quick some times I hit the Rev limiter
peter2b
Blacknight
Joined: Fri 10 Apr, 2015 12:23
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Location: South Wales

Re: M52 vs M54

Post by Blacknight »

Thanks guys

My underlying idea is to take a 2.0 M52TU and look to bore out to 84mm or so to accommodate the better head off the 84mm units and then locate the suitable crank to get it to 2.4 or 2.5 hopefully then keeping it revvy like the short stroke 2.0 (would be crazy to just do 84mm bore on std 2.0 crank?? I think that would be 2.2 on a 67mm stroke)) and within the torque limits of the smaller sweeter gearbox.

Would the 2.0 just have the liner bored to 84mm or is the liner different? It seems a lot of material to be able to remove fom a stock engine?

I see from Wikipedia (so it must be true) there were 2.4 units produced for Thailand and the states had a 2.5 both using 84mm bore.

I know it would be simpler to install the 2.8 and box but that's not what I'm after.
NZ00Z3
Joined: Thu 23 Jun, 2016 01:26
Posts: 95

  Z3 roadster 3.0i

Re: M52 vs M54

Post by NZ00Z3 »

You would need to re-sleeve the cylinder after boring it out. Not sure how practical that would be?

Keep in mind, that you will need to sort out the ECU (DME) to match the new engine capacity. Several options are available:
- Re-map the fuel trims in your existing ECU, Will take some trial and error and you'll need good experience at this sort of thing.
- Buy a M52TU ECU that matches your final engine capacity. Make sure that it is programmed for the same type of transmission as is installed in the car. You'll need to align it with the EWS (security module) or do a EWS delete.
- Convert your car from a M52TU ECU to a M54 ECU that matches your engine capacity. Information is on the web on doing this. Same precautions as buying another M52TU ECU.
deni2s
Joined: Mon 25 Mar, 2013 22:02
Posts: 761

  Z3 roadster 2.8

Re: M52 vs M54

Post by deni2s »

peter2b wrote:my 2.2 m54 revs very quickly too quick some times I hit the Rev limiter
peter2b
Hitting rev limiter on m54 probably is safe. On m52 is common practice to increase rev limit, but I heard that on m54 that is not recommended.
Blacknight
Joined: Fri 10 Apr, 2015 12:23
Posts: 18

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Location: South Wales

Re: M52 vs M54

Post by Blacknight »

NZ00Z3 wrote:You would need to re-sleeve the cylinder after boring it out. Not sure how practical that would be?

Keep in mind, that you will need to sort out the ECU (DME) to match the new engine capacity. Several options are available:
- Re-map the fuel trims in your existing ECU, Will take some trial and error and you'll need good experience at this sort of thing.
- Buy a M52TU ECU that matches your final engine capacity. Make sure that it is programmed for the same type of transmission as is installed in the car. You'll need to align it with the EWS (security module) or do a EWS delete.
- Convert your car from a M52TU ECU to a M54 ECU that matches your engine capacity. Information is on the web on doing this. Same precautions as buying another M52TU ECU.
Or, I suppose, just get a 2.8 block/pistons (accepting that the engine block number will have to be changed on the records) and try to find one of the shorter 2.2, 2.4 or 2.5 cranks. 2.2 crank and 2.8 block would give an OEM 2.4 combination (https://en.wikipedia.org/wiki/BMW_M52).

Looking in to this further it looks like what I am actually after is the M52TUB25 from a M46 323/ E39 523. Shorter stroke with the 84mm bore. Couple this with the benefits of the better head that can go on the 84mm bore and then hope to keep it within the limits of the 2.0 gearbox. ECU problem solved there as well then.

Does anybody know which gearbox the 2.3 / 2.4 / 2.5 (non-UK) models used?
330indy
Joined: Tue 28 Jun, 2016 06:11
Posts: 6

  Z3 roadster 2.5i

Re: M52 vs M54

Post by 330indy »

M54B30 also has a forged crank
Others (non M) are cast
Blacknight
Joined: Fri 10 Apr, 2015 12:23
Posts: 18

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Location: South Wales

Re: M52 vs M54

Post by Blacknight »

330indy wrote:M54B30 also has a forged crank
Others (non M) are cast
Is this of any significant benefit unless you are chasing the large torque of 3.0+ ?
330indy
Joined: Tue 28 Jun, 2016 06:11
Posts: 6

  Z3 roadster 2.5i

Re: M52 vs M54

Post by 330indy »

Probably not
The newer N55 has a cast crank and it's 300/300 hp/tq
Blacknight
Joined: Fri 10 Apr, 2015 12:23
Posts: 18

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Location: South Wales

Re: M52 vs M54 vs N52

Post by Blacknight »

Amendment to the original thread ...

I've just started looking further in to the lineage of the 6cyl engine and go to the N52 which replaced the M54.

https://en.wikipedia.org/wiki/BMW_N52

Some interesting 'improvements' here being the magnesium alloy block, variable valve lift and the variable length intake manifold.

So, would this slot into the Z3 if the cable throttle parts were retro-fitted to get it into a 2.0 / 2.8? Would the variable valve and inlet need to be deleted if its not using the N52 brain?

Seems like a good straightforward upgrgade (as long as you get a post 2008 unit) seeing as the 2.5 is 210ps and the 3.0 270ps (several states of mapped tune available as standard depending on original application).
NZ00Z3
Joined: Thu 23 Jun, 2016 01:26
Posts: 95

  Z3 roadster 3.0i

Re: M52 vs M54 vs N52

Post by NZ00Z3 »

Interesting approach. Hope you have good Electrickery skills or know someone who has.

About this time you should get a full wiring diagram of your car and the donor car. Tack every wire and connection between the ECU/DME and all other systems. Work out if you should remake the connection or delete the connection (and know the work arounds). You'll then have a very good idea of the potential success.

The newer the ECU/DME the harder it is to re-program for work arounds.
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
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  Z3 roadster 1.9

Re: M52 vs M54 vs N52

Post by BladeRunner919 »

What is your end-goal with the car? I assume you have a reason for wanting to do this?
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