Thread: 525i Head
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Old 01-27-2011, 09:09 AM
robertobaggio20 robertobaggio20 is offline
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Join Date: Oct 2009
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Mein Auto: car
It sounds like he's just buying you a replacement head instead of doing any repair....nonsense.

Cracks in heads can only be repaired by certified experts in such things. Its not a simple matter of heating the area with a blowtorch, pouring some metallic filler in and waiting for it to cool nicely. In fact, its very difficult to do, and its much cheaper to just buy a head. Hell, you can get an engine for something like $400-$500.

I'm sure this mechanic is not going to recast the entire head and give you new valves and stuff. Buy a new head yourself, use the money saved to :

1. Check the new head for straightness
2. Conduct a pressure test to make sure its not cracked, if it is, return it for a refund and a reimbursement on the pressure test
3. Have it skimmed down ever so slightly for some added compression. RESIST the urge to compensate for this by using a thicker head gasket.
4. Purchase an M50 Non vanos exhaust cam and swop it with your current vanos exhaust cam for some added power at higher rpms. This should only cost you something like $50-$80.
5. If you've got some money left over, purchase an S50 intake cam for higher lifts. Check with the shop first to see if it will fit a vanos motor. This could set you back up to $200.
6. Take the leftover cams from your old engine and throw it at the dude who claims he can repair your cracked head for $850.

Here's some cam duration in degrees and Lift information that you might find useful (and take your time to do some intensive research on this over the weekend before if you find the idea interesting) :

Motor.........IC/L.................EC/L
M50NV........240/8.8L..............228/9.7L
M50TU........228/9.0L..............228/9.0L
M52............228/9.0L..............228/9.0L
S50............252/9.3L..............244/9.5L
S52 (US M3)....252/10.2L.............244/10.2L
M50NV........240/8.8L..............228/9.7L
M50TU........228/9.0L..............228/9.0L
M52............228/9.0L..............228/9.0L
S50............252/9.3L..............244/9.5L
S52............252/10.2L.............244/10.2L

Euro
s50b30........260/11.3L..............260/11.3L
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