Engine swap

[jmy60]

Hey I know there's been a lot of discussion about the difficulties of doing an engine swap on an E39. I have a 528i and would like to install a 3.0L, M54 engine but they are not really compatible. Better to sell the car and buy a 530i... less hassle etc etc. But here's my question: what if I just change the bare motor...IE block and cylinder assembly? Will it trick the car (ECU etc) or is there something mechanically different that sends a different code to the ECU? Maybe a dumb question but I'm prepared to cop it for asking!

[blackknight530i]

Hey I know there's been a lot of discussion about the difficulties of doing an engine swap on an E39. I have a 528i and would like to install a 3.0L, M54 engine but they are not really compatible. Better to sell the car and buy a 530i... less hassle etc etc. But here's my question: what if I just change the bare motor...IE block and cylinder assembly? Will it trick the car (ECU etc) or is there something mechanically different that sends a different code to the ECU? Maybe a dumb question but I'm prepared to cop it for asking!

I'm not sure why people would think it's easier or even possible to just swap blocks, when changing the engine entirely is actually much easier. Putting a M54b30 in place of a M52TUb28 is not really all that difficult, just time consuming and requires a few extra parts that doing a straight M54-M54 or M52TU-M52TU would be. Mainly it's just running the wires for and installing the e-gas pedal in place of the mechanical one. You'll likely need the transmission from it as well, but even that I'm not sure is required, though I've been pretty happy with my ZF 5hp19 with replaced torque converter over the last 140k miles or so. You'll also need the MS43 from the donor engine, along with the EWS and keys/locks, unless you plan on doing an EWS delete (supposedly can be done) or ISN swap (much more complicated).

Another option I've heard of is people installing the M52TU heads on the M54 block and keeping all the wiring from the M52TU. Check the e46 forums for more info on that as it is more common among those guys. This would allow you to keep the mechanical gas pedal and EWS/locks/keys.

[jmy60]

Thanks blacknight for the insights. Every thread I've seen says it is too hard. ..Your last paragraph is kind of where I was heading. Having said that I believe the M54 has different valves, springs and camshafts but I'm happy to be corrected on that.

[balidawg]

Why do you want an M54B30, when an M52TUB28 is a direct swap? Are the extra 200cc really worth the hassle?

[auaq]

Not sure on the valves and springs but the cams are definitely different at least for the B30 engine.

[TerraPhantm]

I'm not sure why people would think it's easier or even possible to just swap blocks, when changing the engine entirely is actually much easier. Putting a M54b30 in place of a M52TUb28 is not really all that difficult, just time consuming and requires a few extra parts that doing a straight M54-M54 or M52TU-M52TU would be. Mainly it's just running the wires for and installing the e-gas pedal in place of the mechanical one. You'll likely need the transmission from it as well, but even that I'm not sure is required, though I've been pretty happy with my ZF 5hp19 with replaced torque converter over the last 140k miles or so. You'll also need the MS43 from the donor engine, along with the EWS and keys/locks, unless you plan on doing an EWS delete (supposedly can be done) or ISN swap (much more complicated).

Another option I've heard of is people installing the M52TU heads on the M54 block and keeping all the wiring from the M52TU. Check the e46 forums for more info on that as it is more common among those guys. This would allow you to keep the mechanical gas pedal and EWS/locks/keys.

The heads are the same as is the bulk of the wiring. Intake manifold is different (M54 flows much better), and throttle body mount is different (adapters exist).

Fuel system is also a bit different. M54 is atmosphere reference with a non return fuel rail. M52TU is vacuum reference with a "normal" fuel rail. If using the M52TU management, better to use be M52TU fueling parts.

[jdjg]

I stroke my M52TUB25 to a M54B30 specs, using block and cylinder head from my M52TU, I can tell you, both are equal but the internals

the only differences between two motors are:
- internals (camshafts, pistons, rods and camshafts, oil pump) *
- intake manifold
- fuel injectors
- fuel riel (but you can still use your current fuel riel and FPR, thats what I did in my car, still using the M52TU fuel system, just only put the M54B30 injectors)

for sure you can use the long block m54b30 in your car, but you need to use your current intake manifold, throttle body (I did this for a few months in my car, 0 issue)

[rdl]

...
Fuel system is also a bit different. M54 is atmosphere reference ... M52TU is vacuum reference ...

As a matter of interest, I don't think this is really true; technically yes, practically not.

The M54 takes reference pressure for the fuel pressure regulator off the boot between the MAF and throttle body. That will be atmospheric pressure less any pressure drop across the engine air filter. The drop would be virtually zero at idle. I've read that typical values for passenger car engines are 10 - 15 millibar at WOT.

The M52TU takes reference pressure on the crankcase side of the CCV. Which, assuming the CCV is operating properly, is a constant 10 - 15 millibar vacuum.

For comparison 10 millibar = 0.15 psi & TIS says fuel pressure tolerance is +/- 0.2 bar or +/- 2.9 psi. The "vacuum error" and difference between the two engines is a very small fraction of the tolerance.

I suspect that BMW goes to the bother & expense of running the hose from the engine to the fuel pressure regulator is to ensure a filtered, clean supply so that the regulator's pressure reference port isn't exposed to dirt & corrosive road spray at the filter/regulator location. And they probably moved the location on the M54 after learning that CCVs commonly fail with the result that the reference pressure could go seriously +ve or -ve, depending on the CCV failure mode.

[jdjg]

As a matter of interest, I don't think this is really true; technically yes, practically not. The M54 takes reference pressure for the fuel pressure regulator off the boot between the MAF and throttle body. That will be atmospheric pressure less any pressure drop across the engine air filter. The drop would be virtually zero at idle. I've read that typical values for passenger car engines are 10 - 15 millibar at WOT. The M52TU takes reference pressure on the crankcase side of the CCV. Which, assuming the CCV is operating properly, is a constant 10 - 15 millibar vacuum. For comparison 10 millibar = 0.15 psi & TIS says fuel pressure tolerance is +/- 0.2 bar or +/- 2.9 psi. The "vacuum error" and difference between the two engines is a very small fraction of the tolerance. I suspect that BMW goes to the bother & expense of running the hose from the engine to the fuel pressure regulator is to ensure a filtered, clean supply so that the regulator's pressure reference port isn't exposed to dirt & corrosive road spray at the filter/regulator location. And they probably moved the location on the M54 after learning that CCVs commonly fail with the result that the reference pressure could go seriously +ve or -ve, depending on the CCV failure mode.
when I was NA and stroke the motor, Im not replace the fuel system and still using the M52 TU fuel pipe and FPR, I connect the vacuum hose from the FPR to the intake boot (after the MAF) and connect the CCV to the one of the vacuum port in the intake manifold, my car run great..
thanks fir the explanation

[rdl]

when I was NA and stroke the motor, Im not replace the fuel system and still using the M52 TU fuel pipe and FPR, I connect the vacuum hose from the FPR to the intake boot (after the MAF) and connect the CCV to the one of the vacuum port in the intake manifold, my car run great..
thanks fir the explanation

The M54 CCV has a cap on the port that an M52TU would connect to the fuel pressure regulator.
Connecting that CCV port to the inlet manifold negates the CCV's control of crankcase vacuum, at least to some extent, since there is a constant, uncontrolled, manifold vacuum applied to the crankcase. One hopes the small diameter limits flow enough that the CCV is able to compensate. It would be worth your while to check crankcase vacuum to ensure it is in spec of 4 to 6" water column.

[jdjg]

The M54 CCV has a cap on the port that an M52TU would connect to the fuel pressure regulator. Connecting that CCV port to the inlet manifold negates the CCV's control of crankcase vacuum, at least to some extent, since there is a constant, uncontrolled, manifold vacuum applied to the crankcase. One hopes the small diameter limits flow enough that the CCV is able to compensate. It would be worth your while to check crankcase vacuum to ensure it is in spec of 4 to 6" water column.
Im FI right now (ESS TS2+), no more CCV for me..... but thanks for the advice