E30 Zone

Hi, just wonder how big is the difference between
the 2 heads the 200 bhp , AND 215 bhp, apart from the
price the 200 bhp one is the grand , and 215bhp one is over 2.5 grand
the inlet ports size is the same , just the middle a touch shaved
off,
, the overall height is the same

this is 215 bhp vew, the middle shaved off



but it can't be the reason behind the price deference or can it?
200 bhp head

if this bit in the middle is the only thing , the one could just take it to the machine workshop and
grade sharp corner off ??

it's not just the bit in the middle, it's the whole shape and size of the port, although you'd need to offer up a throttlebody rubber block from a 215 car to a 200 head to see just how much meat would need to be removed.

not sure whether theyre the same basic casting or whether the later head is modified internally to allow for the larger ports.

if they start the same then there's no reason why an early head couldn't be opened up to 215 spec (or beyond) however, decent headwork isnt cheap.

If the difference is 1.5k then that cash could be spent on the cheaper head to produce something even better than the 215hp head.
1.5k buys a lot of large valves, welding and porting.
Anything mass produced can be improved upon, even superbike and aftermarket billet heads.

Here are two heads side by side.





The casting is also different, the 215hb heads offers the option of running larger valves as they are very slightly further spaced apart, this is also true for the cam box tappet spacing between the 'early' and 'late' engines. The early 195hp heads have 26mm ports and the later 215hp heads have 28mm ports. You can most certainly port out a 195hp head to 215hp spec.

You would also be shocked at the fuel and ignition maps between the two heads, a 195hp engine wont even idle with a 215hp ecu.

Andrew

Demlotcrew wrote:Here are two heads side by side.





The casting is also different, the 215hb heads offers the option of running larger valves as they are very slightly further spaced apart, this is also true for the cam box tappet spacing between the 'early' and 'late' engines. The early 195hp heads have 26mm ports and the later 215hp heads have 28mm ports. You can most certainly port out a 195hp head to 215hp spec.

You would also be shocked at the fuel and ignition maps between the two heads, a 195hp engine wont even idle with a 215hp ecu.

Andrew

Andrew thank you , for help,
so from what i understand , the valves are the same size ,
all i have to do is bore the inlet ports out a bit , and it shouldn't cost me 1,5 grand , the inlet valve size the same,
the reason i strarted this thread is , in case i ever need to change cylinder head on my M , all i have to do is buy 195 bhp head. and save a lot of money.
by the way , retrimmed my interior , some time ago,
she had respray as well , few weeks ago too,

Nice motor