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58mm of Bliss
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Discussion Starter #1 (Edited)
I figured I should start a thread to house the mountain of details I've learned about the M54B30 engine. If anyone has any verified specs that they would like to share, please comment and I'll work towards adding them below. The list will grow shortly....

Combustion Chamber Volume (Head) = 34cc

Intake valve size = 33mm
Intake valve weight = 45 grams

Exhaust valve size = 30.5mm
Exhaust valve weight = 47 grams

Piston size = 84mm
Piston weight (w/rings) = 313 grams
Piston pin weight = 108 grams
Rod + bearing weight = 602 grams

My Arrow rod/ CP piston combo weighed 926 grams....

Cylinder Head Flow:

 

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58mm of Bliss
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Discussion Starter #2
Ever wanted to know what the combustion chamber volume is?

Me too:







Adding water:



I ran into a problem trying to get the last bit of water to fit in. The problem? Surface tension. The solution? A bit of Royal Purple "Purple Ice" coolant treatment which has the same effect as a detergent:



Total volume is 34cc.
 

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Very cool !

And good to know.


Rob
 

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Are those stock heads? I can't see a lot of material being removed if headwork was done.
 

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Maybe I'm thinking incorrectly, but there is no "quench" area to mill down. I think I may be off with my thinking.
 

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58mm of Bliss
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Discussion Starter #8
Maybe I'm thinking incorrectly, but there is no "quench" area to mill down. I think I may be off with my thinking.
That is not something that is normally modified with the head. Normally, if you want to change the quench, you do it in piston design.
 

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Very interesting ...
 

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58mm of Bliss
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Discussion Starter #17 (Edited)
I've measured this stuff a number of times, and I'm still coming up with the same numbers. So here's what's been bothering me:

Cylinder bore = 3.307"
Stroke = 3.528"
Combustion chamber volume = 34cc
Piston/cylinder volume below deck = 17.4cc
Head gasket thickness = 0.030"
Head gasket bore = 3.346"

Plug all those numbers into a compression ratio calculator and you get 9.911:1.

BMW advertises 10.2:1 for the M54B30

The only thing I can guess is that BMW is not including the volume inside the spark plug, and the area above the first piston ring along the cylinder wall. The actual "pour volume" using fluid equals 55.723 inside the combustion chamber with the piston at TDC. Dropping that by just 2cc brings the compression ratio to 10.24:1, which might be the case if you didn't include the spark plug volume ect....

I'm sticking with real world numbers, so the M54B30 in my books is a 9.9:1 engine.

The CP pistons I have pictured above netted a compression ratio of 9.26:1 with a "pour volume" of 60.823cc.

Using a well known engine calculation software package, I was able to build a "model" of my engine to represent the actual power it made on the dyno. (252hp/229tq)

I then changed the compression ratio from 9.26 to 11.4:1 and netted a calculated 265hp/241tq @ 6400 RPM which was closer to what I was expecting when I built the engine.
 

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58mm of Bliss
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Discussion Starter #18
Adding the custom Schrick cams/valvetrain to the 11.4:1 engine would have theoretically moved the peak power RPM to 7500 RPM netting 317hp/245tq. Clearly a different intake manifold would be needed than the OEM M54B30 piece to achieve these numbers. It's fun to work with the numbers though....
 

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I've measured this stuff a number of times, and I'm still coming up with the same numbers. So here's what's been bothering me:

Cylinder bore = 3.307"
Stroke = 3.528"
Combustion chamber volume = 34cc
Piston/cylinder volume below deck = 17.4cc
Head gasket thickness = 0.030"
Head gasket bore = 3.346"

Plug all those numbers into a compression ratio calculator and you get 9.911:1.

BMW advertises 10.2:1 for the M54B30

The only thing I can guess is that BMW is not including the volume inside the spark plug, and the area above the first piston ring along the cylinder wall. The actual "pour volume" using fluid equals 55.723 inside the combustion chamber with the piston at TDC. Dropping that by just 2cc brings the compression ratio to 10.24:1, which might be the case if you didn't include the spark plug volume ect....

I'm sticking with real world numbers, so the M54B30 in my books is a 9.9:1 engine.

The CP pistons I have pictured above netted a compression ratio of 9.26:1 with a "pour volume" of 60.823cc.

Using a well known engine calculation software package, I was able to build a "model" of my engine to represent the actual power it made on the dyno. (252hp/229tq)

I then changed the compression ratio from 9.26 to 11.4:1 and netted a calculated 265hp/241tq @ 6400 RPM which was closer to what I was expecting when I built the engine.
Adam,

I was getting something close to those numbers, with a 33cc combustion chamber volume. I may have some insight to add tomorrow when I go to the machine shop. I have some printed calculation sheets with some of the numbers that CP uses, such as compressed gasket thickness (I believe .025). Also, aren't your CPs 84.5mm? My cylinder bore was 3.328. I'm guessing you were referring to the measurements for the stock pistons?
 

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58mm of Bliss
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Discussion Starter #20
Adam,

I was getting something close to those numbers, with a 33cc combustion chamber volume. I may have some insight to add tomorrow when I go to the machine shop. I have some printed calculation sheets with some of the numbers that CP uses, such as compressed gasket thickness (I believe .025). Also, aren't your CPs 84.5mm? My cylinder bore was 3.328. I'm guessing you were referring to the measurements for the stock pistons?
For the OEM calcs, I used 84mm bore.

I measured used gaskets that had already been compressed, and found them to be 0.030" thick. I have a new gasket at the shop I could measure for reference as well. (I'm amazed how much "new" stuff I still have)

Were you measuring the head with the spark plug installed?
 
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