731 head?

[eko]

Am I right in thinking an M20 731 head is the prefered choice for 2.7 build?

[fowler]

885 bert !!! alll the way depends how you are building it of course

[eko]

885 bert !!! alll the way depends how you are building it of course

Cheers Ben

[fowler]

nay probs mate 731 is 2.0ltr head FYI

[eko]

nay probs mate 731 is 2.0ltr head FYI

Yeah I knew that part already

[daimlerman]

885 bert !!! alll the way depends how you are building it of course

Depends on what you want from your engine and what bits you have to hand,and on how much you want/can afford to spend.If you are using a standard eta short motor,731 head is best as it has the same combustion chamber shape as the eta's 200 head.If you are using 325 pistons,then the 885 head's chambers are better suited.BUT,using 325 piston opens up the can marked 'decking the block' and it's mate marked 'vernier pulley',all adding to the cost o the build.IMO,the best choice is standard eta short motor with 731 head modded to take 325 valves,your choice of cam will dictate where your power band is,stock 325 will give a wide spread of grunt from silly low engine speeds whereas a lumpy aftermarket item will give a poor idle but rocket ship grunt above,what,4000rpm.The big difference with a 2.7 is the increase in torque at low engine speeds,this gives a car with plenty of 'usable' power just where you need it for overtaking.Best decision I made when my 320 needed a new engine was to build it a 2.7.

[eko]

Ah so my thinking was infact correct

[antony]

Sorry, off topic, but what head gasket do you use with the 731 head?

Will a 325i (885) one work?

[daimlerman]

Sorry, off topic, but what head gasket do you use with the 731 head?

Will a 325i (885) one work?

Use the gasket to suit the bore size...

[antony]

A 325i (885) gasket is the right bore size, but doesn't it have more water jackets? (think I've used the right terminology)

Would that effect it? or should I use a 525ee head gasket?

It's just that that gaskets come in sets here, and would be much easier just to get a 325i set. (I have the inlet manifold).

[daimlerman]

A 325i (885) gasket is the right bore size, but doesn't it have more water jackets? (think I've used the right terminology)

Would that effect it? or should I use a 525ee head gasket?

It's just that that gaskets come in sets here, and would be much easier just to get a 325i set. (I have the inlet manifold).

Seem to remember that my last gasket set was marked 325i/525e...you can always compare the gasket to the head/block and punch out any missing holes,extra holes in the gasket will not matter.

[antony]

Thanks.