N55 swaps/interchangability

Bnks334

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Dec 1, 2016
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No one said anything about swapping the tensioner. They are unique for the each of the two styles of fuel pumps. So if you were to get a block with the wrong style of tensioner for your pump then you may run into issues. I ran into an issue using the older E chassis N55 in an F30. Oil pump chain kept coming off and we narrowed it down to the pump being the only difference that could cause it.


That is interesting. Its actually the vacumm pump that the chain drives. Havent heard of anyone else having this issue and quite a few have used late model blocks and swapped in their early n54 style hpfp.

And, if what your saying wasnt related to a weak tensioner or stretched chain the , yes, you are saying that it has to be swapped...
 

silverstreak18

Corporal
Jan 3, 2018
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Charlotte, NC
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2016 M3
That is interesting. Its actually the vacumm pump that the chain drives. Havent heard of anyone else having this issue and quite a few have used late model blocks and swapped in their early n54 style hpfp.

And, if what your saying wasnt related to a weak tensioner or stretched chain the , yes, you are saying that it has to be swapped...
You can not swap them, and once again I never said anything about swapping them. The hydraulic tensioner in the late model blocks is probably more than adequate for the older style pumps. I stated that I was having issues with the older motor in a newer F30 which uses the piston style fuel pump. The issue we suspect is that the leaf spring style tensioner wasn't strong enough.
 

Bnks334

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Dec 1, 2016
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You can not swap them, and once again I never said anything about swapping them. The hydraulic tensioner in the late model blocks is probably more than adequate for the older style pumps. I stated that I was having issues with the older motor in a newer F30 which uses the piston style fuel pump. The issue we suspect is that the leaf spring style tensioner wasn't strong enough.

You're referring to part #8?: https://www.realoem.com/bmw/enUS/showparts?id=UC93-USA-12-2010-E82-BMW-135i&diagId=11_4464

I remember seeing that part on realoem and TIS but have not had to mess with it. My own car is pre 12/2011 build date so it's not there. I don't see why it can't be retrofitted? Does it need an oil galley there or something to feed it that isn't there on the older style block? The guide appears to be the same. I've always gone the other direction as most others do... newer style blocks in older cars. I have the newer style cylinder head mated to my bottom end (with the top mount injectors). Much easier to service than the bottom mount style injectors from 2010-2011 build date cars.

I don't remember, can the N54 style HPFP be retrofitted for these situations? Taken everything from the old block from the vacuum pump up to the injectors?
 
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silverstreak18

Corporal
Jan 3, 2018
129
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Charlotte, NC
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2016 M3
You're referring to part #8?: https://www.realoem.com/bmw/enUS/showparts?id=UC93-USA-12-2010-E82-BMW-135i&diagId=11_4464

I remember seeing that part on realoem and TIS but have not had to mess with it. My own car is pre 12/2011 build date so it's not there. I don't see why it can't be retrofitted? Does it need an oil galley there or something to feed it that isn't there on the older style block? The guide appears to be the same. I've always gone the other direction as most others do... newer style blocks in older cars. I have the newer style cylinder head mated to my bottom end (with the top mount injectors). Much easier to service than the bottom mount style injectors from 2010-2011 build date cars.

I don't remember, can the N54 style HPFP be retrofitted for these situations? Taken everything from the old block from the vacuum pump up to the injectors?
Yes that's it! See how it has two bolts into the block? The older blocks have nowhere to mount that tensioner.
 

Afastboy

New Member
Feb 19, 2020
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My mechanic as an upgrade option installed an n54 crank in my 2011 n55...now belt alignment is all out of whack and needs spaced. No information on the net of anybody running into issues with this retro fit but clearly there is no direct swap.
 

Bnks334

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Dec 1, 2016
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My mechanic as an upgrade option installed an n54 crank in my 2011 n55...now belt alignment is all out of whack and needs spaced. No information on the net of anybody running into issues with this retro fit but clearly there is no direct swap.

N54 crank swap should not affect belt alignment at all.
 

Afastboy

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Feb 19, 2020
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N54 crank swap should not affect belt alignment at all.
This was the attempt at spacing the crank, it wobbled terribly with these .050” thick copper washers, could it be that accessory pulleys are still N55? Should I order N54 accessory pulleys to match the N54 crank? N54 and N55 have different part numbers for accessory pulleys and belt so I assume there either bigger OD or wider, I am hoping that possibly fixes the belt alignment. CC2B3A1B-0512-4659-BE18-8A78D1C7EE6F.jpeg
 

Bnks334

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Dec 1, 2016
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This was the attempt at spacing the crank, it wobbled terribly with these .050” thick copper washers, could it be that accessory pulleys are still N55? Should I order N54 accessory pulleys to match the N54 crank? N54 and N55 have different part numbers for accessory pulleys and belt so I assume there either bigger OD or wider, I am hoping that possibly fixes the belt alignment. View attachment 35288

This thread is not about swapping an n54 engine into an n55 car if that's what you did. If all you did was an N54 crank into an n55 engine then are you using the N54 damper or N55? Try using the N55 damper?

I know for a fact that an N54 tensionor will cause the belt to slip off if accidentally installed on an N55. The belt size thing is weird but I think the 5mm difference in the two available belts has to do with ROUTING. I have ran both length belts on my n55 without issue.
 

Afastboy

New Member
Feb 19, 2020
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You are using the N54 damper? Use the N55 damper?

I know for a fact that an N54 tensionor will cause the belt to slip off if accidentally installed on an N55. The belt size thing is weird but I think the 5mm difference in the two available belts has to do with ROUTING. I have ran both length belts on my n55 without issue.
N54 dampener as the crank is 6 bolt, N55 is 8 bolt so won’t interchange.
 

Bnks334

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Dec 1, 2016
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N54 dampener as the crank is 6 bolt, N55 is 8 bolt so won’t interchange.

So then yeah I would try an N54 tensionor but I can't say whether or not it will actually change anything. definitely don't try to space out the damper you'll throw the crankshaft balance off.
 

Afastboy

New Member
Feb 19, 2020
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Going to use this spacer made out of aluminum if the tensioner doesn’t help/work..it’s obvious that the crank pulley is significantly further in towards the motor then the ps/alternator/ac compressor pulleys. The spacer will be hub concentric but about .05” is the max I think I can safely space.
image.jpg
 

chrisirvine

New Member
Oct 9, 2019
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How did it work with the coding on your DME, my swap is all done but it still needs to be coded and BMW told me to kick rocks
 

Chrisirvine1

New Member
Feb 26, 2020
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You should be fine, Much less work than my automotive adventure. I’d double check/cross reference the following part numbers with realoem:
Oil pan
Wastegate
Vibration Damper
I got a little carried away with my motor swap. It’s turned into a kind of restoration + virtually every conceivable bolt on (a bit of exaggeration).
I’ve found this particular forum extremely helpful to a BMW neophyte like myself.
If you have any questions, feel free to ask.

Mike


Did you finish your swap yet? Mine is done but i can't get the car to start because of the DME and it needs to be coded, BMW told me to kick rocks
 

mjg0915

New Member
Feb 26, 2020
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I can confirm there's a belt alignment issue with the N54 crankshaft in an N55 engine. Its a matter of the belt rubbing on the bedplate/block without some kind of shim to bring the crank pulley/vib dampener out somewhere in the 2mm range. I'd be interested in seeing the dimensions of the single piece shim. I was thinking of using copper but aluminum is probably better for this application.
 

mjg0915

New Member
Feb 26, 2020
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This was the attempt at spacing the crank, it wobbled terribly with these .050” thick copper washers, could it be that accessory pulleys are still N55? Should I order N54 accessory pulleys to match the N54 crank? N54 and N55 have different part numbers for accessory pulleys and belt so I assume there either bigger OD or wider, I am hoping that possibly fixes the belt alignment. View attachment 35288
Did this fix the belt alignment issue though or could you tell with it wobbling so badly?
 

JarJarKIll

New Member
Jul 3, 2020
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So im trying to prepare for the inevitable. I have a 2012 135i dct and wondering what n55 engines would be interchangeable with this car. I hope the forged 235i/M2 engine would be a easy swap in this car. Have intentions of added a big turbo so looking to have some forged internals. Ive read this forum i understand how a n54 to n55 would potentially be a issue but would n55 to n55 or this black cap for hydraulic on the 235i/m2 motor?