Ok so my 2.7 will have an Alpina profile cam and there the similarity ends......
but out of interest what were the specs of the original C2, i.e Compression Ratio, BHP, lbft, what block head piston crank combo was used. And what fuelling was used, was it just remapped 325 motromic and injectors?
I'm just trying to decide what sort of power/torque my 2.7 will produce in comparison,
Cheers guys
Alpina 2.7 C2 specs anyone?
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M5pilot
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268 cam
Steel Crank 81mm
Alpina Specified Mahle pistons
Compression ratio a claimed 10.2:1
320i/ETA rods (Same thing)
325i Head with additional work and apprently bigger valves
Fuelling: Exactly the same as the 325i but with a different mapping to suit the 2.7
Claimed output:
210bhp @ 5800 rpm
213 lb.ft @ 4500 rpm
In reality its more like 200 bhp and 200 lb.ft
All 2.7's will have the same sort of power if the correct compression ratio and piston type are used.
Steel Crank 81mm
Alpina Specified Mahle pistons
Compression ratio a claimed 10.2:1
320i/ETA rods (Same thing)
325i Head with additional work and apprently bigger valves
Fuelling: Exactly the same as the 325i but with a different mapping to suit the 2.7
Claimed output:
210bhp @ 5800 rpm
213 lb.ft @ 4500 rpm
In reality its more like 200 bhp and 200 lb.ft
All 2.7's will have the same sort of power if the correct compression ratio and piston type are used.
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Widge
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Cheers mate,
That's just what I wanted to know. So realistically with out head work and special pistons I should be able to get 185bhp + if I'm lucky, and a bag of torque. I calculated my compression ratio to be 10.6:1, but that depends on the machining.
That's just what I wanted to know. So realistically with out head work and special pistons I should be able to get 185bhp + if I'm lucky, and a bag of torque. I calculated my compression ratio to be 10.6:1, but that depends on the machining.
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M5pilot
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Head work wont give you 15bhp!
You should still get 200bhp
Your CR is very very high! You will need a remap 100% otherwise its pinking time.
You should still get 200bhp
Your CR is very very high! You will need a remap 100% otherwise its pinking time.
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Widge
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That;s good news, I get the impression on here that the M20 head flows weel as a standard unit. I think the compression ratio will be more like 9.8:1 it's only my dodgy maths and a few dodgy assumptions that got me to 10.6 
Just as long as it's highter than the 8.8:1 some of the M20's have I'll be happy 
I think my lump could turn out to be quite good, I'm more interested in torque than out and out bhp really.
Just as long as it's highter than the 8.8:1 some of the M20's have I'll be happy I think my lump could turn out to be quite good, I'm more interested in torque than out and out bhp really.
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Karan
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i believe mine to be slightly over 10:1 and it seems fine.....aparently it used to pink but it seems fine sinced i bought it....
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Widge
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Well I suppose it depends on the setup fuelling and timing Karan, and as you said in another thread you'rs has been developed alot.
I got to the 10.6 CR by using 44cc as the combustion chamber size and 2692cc as the swept volume, but obviously these will both change sutbly when I have the block decked. It'll only take a small combustion chamber size change to lower the CR.
I got to the 10.6 CR by using 44cc as the combustion chamber size and 2692cc as the swept volume, but obviously these will both change sutbly when I have the block decked. It'll only take a small combustion chamber size change to lower the CR.