NA 55 vs 55k Internals (pics inside)
#1
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NA 55 vs 55k Internals (pics inside)
Since I have 55k rods/pistons and NA 55 rods/pistons I decided to share with the board what I've found.
Both rods are crack forged. The biggest difference is the oiling port in the NA 55 rod (bottom) which weakens the rod
Notice the difference in wrist pins (NA 55 on top)
The NA 55 (bottom) has higher compression as expected.
NA 55 on right
The 55k pistons look to have really low compression. I have an 06 E55 engine on it's way to me and I will tear it down and put higher compression forged pistons, ARP head studs, and rod bolts in it. This should beef it up a bit. I want higher compression than stock because I want more power per psi and off boost power. I can post differences in the heads, blocks, etc if I get the time. The NA motor was able to hold over 650whp and in my CLK55 was able to trap 138.71 before letting go. I would expect the 55k motor to be able to hold more power but I'm not willing to put the stock 55k motor in my car and risk it blowing up and putting me and the car into the wall.
Both rods are crack forged. The biggest difference is the oiling port in the NA 55 rod (bottom) which weakens the rod
Notice the difference in wrist pins (NA 55 on top)
The NA 55 (bottom) has higher compression as expected.
NA 55 on right
The 55k pistons look to have really low compression. I have an 06 E55 engine on it's way to me and I will tear it down and put higher compression forged pistons, ARP head studs, and rod bolts in it. This should beef it up a bit. I want higher compression than stock because I want more power per psi and off boost power. I can post differences in the heads, blocks, etc if I get the time. The NA motor was able to hold over 650whp and in my CLK55 was able to trap 138.71 before letting go. I would expect the 55k motor to be able to hold more power but I'm not willing to put the stock 55k motor in my car and risk it blowing up and putting me and the car into the wall.
Last edited by blackbenzz; 04-29-2014 at 12:06 PM.
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#4
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You're both welcome. I will post pics of Mahle forged "SLR" pistons later as well as some other pics like ARP rod bolts and ARP head studs. I no longer have the Mahle forged pistons so I don't have many pictures of them and they were already in a 55k block. But it's better than nothing. I will have side by side pics after my custom forged pistons are made comparing them to the NA 55 and 55k pistons.
#5
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what do you think the cost on building your new block will cost?
also was the 55K piston used? Why so much discoloration between the two?
also was the 55K piston used? Why so much discoloration between the two?
#6
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Yes 55k Piston came out of my old E55. Had ~82k miles on it. I cleaned it up and it has been sitting in basement for 2 years or so. The NA 55 is fresh out the block and not cleaned up (~102k miles). Probably should have cleaned it up, sorry.
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#10
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Nice thread, plus you forget to mention the difference in weight between both pistons, as i remember when i built my engine that the n/a 55 piston alone is less weight then those of 55K(580g for 55k and 530g for n/***).
also the heads differ in volumes the 55k ones are slightly bigger.
n/a 55:
Attachment 285458
55k:
Attachment 285459
also the heads differ in volumes the 55k ones are slightly bigger.
n/a 55:
Attachment 285458
55k:
Attachment 285459
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Dirt Scooters
The N/A heads and S/C heads have the same combustion chamber volume. The intake runner volume is actually more on the N/A head but I don't remember the exact volumes of the runners but the CC volume on both heads is 60cc's.
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Yes the can be run on a 55k bottom end. I actually bought a set of N/A heads for my build thinking they were the same and found out after having them ported and taking the 55k heads off. My head porter ended up porting a 55k set also and then took a spare set of N/A heads and S/C heads and played with several ports trying things on both and said the N/A head was the way to go in his opinion. I think Ahmad might have pics of the intake ports of both to show the difference. The 55k heads have a raised divider that the n/a heads don't.
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Getting pistons and rod bolts through Weistec. Ceramic coated tops with teflon coated skirts. 9.8:1 C/R is what I decided to go with.
Yes the can be run on a 55k bottom end. I actually bought a set of N/A heads for my build thinking they were the same and found out after having them ported and taking the 55k heads off. My head porter ended up porting a 55k set also and then took a spare set of N/A heads and S/C heads and played with several ports trying things on both and said the N/A head was the way to go in his opinion. I think Ahmad might have pics of the intake ports of both to show the difference. The 55k heads have a raised divider that the n/a heads don't.
I agree! You're welcome
Just to add a bit more info and pics to this thread. First off if you plan on running NA heads please make sure you run the shorter plugs because if you run 55k plugs they are too long and will hit!. You will do alot of damage on first start up. This is why I always recommend to hand turn the crank several times before starting the car after doing any engine work.
Pic of NA 55 head ported intake
Pic of unported NA 55 head intake (I will get comparison pics of all 3 when my 55k engine gets here to disassemble)
I promised a pic of the Mahle forged "SLR" pistons so I found a couple on my phone. I bought the block with them in it and was told not to remove them so the pics I took were with the pistons still in the block sorry. There's an obvious difference from the bottom (and they are lighter)
NA 55 piston from bottom in block
From the top they look like a compromise between the NA 55 and 55k pistons... but forged. So the compression is somewhere between the 2.
You'd have to be a detective to notice the minute differences between a NA 55 block and a 55k block. One thing I did run into is that the 06 E55 block apparently has a different crank than a NA 55 (I'm not sure about the other years). The flywheel wouldn't bolt to the 55k crank because of different spacing (55k on left)
This pic gives you an idea of NA 55 pistons vs the Mahle forged ones in the block.
Pic of ARP rod bolts on 55k rod
This pic is a comparison of one variation of the 55k oil pump (I wanna say S55 but can't remember right now. Either way it's different than E55 because of the different oil pans to fit different cars) and a W208 CLK55. It's hard to tell in this pic but they are not interchangeable because of the different bolt hole spacing! Also the pickups are in different locations. Just a nice surprise I ran into when trying to do a 55k block in my car before. I had to buy 2 oil pumps (which wasn't exactly cheap) and use the front half of one and bolt it to the back half of the other in other for the correct oil pan to fit... but it works!
You can see the spacing issue in this pic if you look closely. (Na 55 oil pump on a 55k block)
And just for fun here's a pic of the NA 55 piston that broke and got lodged in the cylinder the first time an NA 55 motor let go on me. I haven't removed the piston from the most recent one since I'm leaving it in the block when it becomes a table. It adds character lol
Hopefully all this info will help some people in the future and save them alot of time and $$$
Last edited by blackbenzz; 04-30-2014 at 10:57 AM.
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M113 E50 6-speed, 2005 E55 AMG
MB changed the crank bolt pattern in 05 on most models, others earlier, others later. If you need a flexplate for the newer bolt pattern let me know. Thanks for the pics and descriptions though, awesome information.
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06 E55 AMG, 13 C63 AMG
I am going to be installing a used engine from an 05 S55 in my 06 E55. Is this going to cause me a problem with the crank shaft?
The S55 engine does have the flex plate on it.
Looking at the oil pump in the pictures above. Word is I will need to move the oil pump from the E55 engine to the new/used engine. Will that require removing the front timing chain cover to make the swap?
G
The S55 engine does have the flex plate on it.
Looking at the oil pump in the pictures above. Word is I will need to move the oil pump from the E55 engine to the new/used engine. Will that require removing the front timing chain cover to make the swap?
G
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M113 E50 6-speed, 2005 E55 AMG
The torque converter has to match the flexplate. I'm not sure which models changed and which didn't but I believe S and E both changed in 2005, so you should be ok.
You can change the pump's with just the pans off. Way easier if the motor's out though. I just flipped the whole motor over lol.
You can change the pump's with just the pans off. Way easier if the motor's out though. I just flipped the whole motor over lol.
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M113 E50 6-speed, 2005 E55 AMG
Totally understandable, if you can PM the block number on the S and on the E I can check in the EPC to see if their the same bolt pattern. That would be your only issue, everything else can just be swapped over or around if needed.
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The torque converter has to match the flexplate. I'm not sure which models changed and which didn't but I believe S and E both changed in 2005, so you should be ok.
You can change the pump's with just the pans off. Way easier if the motor's out though. I just flipped the whole motor over lol.
You can change the pump's with just the pans off. Way easier if the motor's out though. I just flipped the whole motor over lol.
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M113 E50 6-speed, 2005 E55 AMG
No clue why they changed, it's actually very irritating and cost me like $1300 in a useless flywheel and clutch from a newer C230.
Matching torque converters to flexplates is a hit or miss. The converter bolt pattern (as far as I'm aware) did change along with the redesigned crank bolt pattern, but like I said, most M113's changed in 05, where as some changed in '04 and some in '06. So it's hard to say if you got lucky, or if the converter bolt pattern mates to all of the flexplate's... Honestly man I can't tell you 100%, I'm basing this off my experience which is limited for the auto's. I have the redesigned flexplate and an older converter, so I'll see if they mate up and text you.
#25
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Thanks
The converter bolted to the flex plate I had. I have an 01 and it bolted to 06 flex plate.
Here is a pic comparison for those who haven't seen it (06 crank on top. Notice the bolt hole spacing and two extra holes).
No clue why they changed, it's actually very irritating and cost me like $1300 in a useless flywheel and clutch from a newer C230.
Matching torque converters to flexplates is a hit or miss. The converter bolt pattern (as far as I'm aware) did change along with the redesigned crank bolt pattern, but like I said, most M113's changed in 05, where as some changed in '04 and some in '06. So it's hard to say if you got lucky, or if the converter bolt pattern mates to all of the flexplate's... Honestly man I can't tell you 100%, I'm basing this off my experience which is limited for the auto's. I have the redesigned flexplate and an older converter, so I'll see if they mate up and text you.
Matching torque converters to flexplates is a hit or miss. The converter bolt pattern (as far as I'm aware) did change along with the redesigned crank bolt pattern, but like I said, most M113's changed in 05, where as some changed in '04 and some in '06. So it's hard to say if you got lucky, or if the converter bolt pattern mates to all of the flexplate's... Honestly man I can't tell you 100%, I'm basing this off my experience which is limited for the auto's. I have the redesigned flexplate and an older converter, so I'll see if they mate up and text you.
Here is a pic comparison for those who haven't seen it (06 crank on top. Notice the bolt hole spacing and two extra holes).