m60 3.0 vs. 4.0

[chris_e34]

It has been a while. i would like to say hello to everyone. this forum has changed alot...well i have aquired many parts for my 540 race engine, but the biggest concern is the differences between the m60 3.0 heads and 4.0 heads. are they interchangeable?.pros, cons,differences if any. i have an extensive parts inventory for many e34's, but the best condition heads i have for an m60 are 3.0 heads. my plans are for a highly modified 1000hp+ supercharged drag e34 so planning is key. please any input appreciated. thanks

[Barney Paull-Edwards]

Various european tuners use versions of the M60,Ascari,Morgan,Noble proto,etc,outputs from some are legendary,Overfinch used to sell a 480hp Range-Rover with M60.A German tuner by the name of Heini Mader tunes them to good effect in loads of race cars. With forced induction you should see four figures with reliabilty, not for shopping but not a grenade job! Somebody near here has a 740 Sport manual with a weaver dry sump pump,you can hear the pump coming way before the car!It has "guard" features so needs the power.

[chris_e34]

they are definitley good for some serious power. my inspiration is from v.s. motors supercharged 1290hp e34 m5. not an m60 but i like the way these cars handle with more weight up front

[chris_e34]

anybody know if i can use 3.0 heads on a 4.0 block? 3.0 and 4.0 heads look the same sitting next to each other.

[Antrieb]

I have heard of people using the 3.0 heads but I don't think there would be any gains. The 3.0 heads don't flow as well as the 4.0 ones. Also putting on the 3.0 heads will raise the compression quite a bit which would be bad for forced induction. I would say don't do it.

[chris_e34]

im not looking for gains, just trying to save money on rebuilding the 4.0 heads i have. i have a freshly rebuilt pair of 3.0 heads. how much do you think it would raise the compression?

[Antrieb]

I'm not exactly sure what the final compression would be but I know it would be a little too high for FI.

The differences are :

Valves are 2mm bigger on 4.0
Intake and exhaust ports are large on 4.0 heads
Maf is bigger on 4.0
Displacement goes up ion 4.0
Everything is forged internally on 4.0
OEM ECU programming is different...

...

Cams are the same, intake manifold is the same, exhaust is the same.

[stevie s]

nice to know someone else is building a non m5 drag e34.. what sort of spec were you thinking of using?
Steve

[Ferret]

exhaust is the same.

Really?

I was under the impression that the 4.0 had a bigger exhaust bore - hence the different part numbers, and the fact it's almost impossible to get one in the UK...

On a side note, as someone who's fitted smaller heads to an engine, it's NOT a good idea. Usually the compression chambers are smaller diameter - even slightly - producing a lip on the edge of the piston bores. If you start to get ANY play in the bottom end bearings, and at that compression you will within 2 months/immediately, the pistons will strike the heads and it's game over.

My first E34 was a 525i with a 520 head on it, it was insanely quick, but didnt last!

[chris_e34]

its an ongoing process, lots of money being poured into raising power from a 4.0 m60. not going into specifics (i am a thoroughbred Virginia drag racer that likes his **** to remain a secret regarding racing.) forced induction is the last bit of my strategy. pure engine power is hopeful of at least 460-500 hp. with nitrous i am hoping for 560-600. and with forced induction another few hundred horses. these numbers are complete estimates and the farthest i have come on this project is assembling the block with performance internals. i have yet to source another e34 to drop it into. my inspiration is that of the v.s. motors m5 squatting like a champ and then stomping a 7 second quarter.