320i head for a 327 build

[whipsey]

i've read in the e30 restoration bible that you can use a 320 head for building a 2.7 engine is this correct as every body else seems to be uing a 325 one?

[gooner1]

Well, it.s in the sticky too Sean, so would take it as read mate.

[daimlerman]

As Andyboy writes in the sticky,using a 731 (or 320/520) head is one option.Depends on the depth of your pocket and your requirements of your engine.The basic eta 2.7 short motor(that is to say,the block with 'rods,crank and standard pistons) comes with 'flat' topped pistons,just like a 320,so the 731 head's combustion chamber is suited to the piston.The 885(325) head,has a chamber suited best to 325 pistons,which have a different top shape.The 885 head fits and works fine,Chromiebabe is using this combo,but it is not ideal.Using standard eta pistons,the best combo is 731 head with the larger valves from the 885 head and your choice of cam.

[whipsey]

so if i get some valves from a 325 head and a schrick cam with a525e bottom end it should be a good one then?

[Alex]

from what i know the 731 head (320i) is the easyway to do it fit it on a 525e bottom end and you have an instant 2.7 but top end can be a little flat, will be very torquey tho

iirc the 325i head needs skimming or something to fit a 525e bottom end

[whipsey]

the head i have looks very new to be honest so i may as well make some use of it lol

[cliffybabe]

im running a 325 885 head with a eta bottom end, I think there little difference between the 2 builds using a 2.5 or 2litre head Im running 194torq and 174bhp.

I am running on a standard cam soon to be changed plus im looking into a live remap but 194torq for a straight forward build i think is cracking.

I cant take credit for my build as Nelly done all the work but it does feel very strong threw the gears

I think the main reason people use the 2.5 heads is due to the the fact it has large ports on it etc allowing few more ponys, also using a 2.5 inlet and TB will give u a bit more bolted to the 2ltre head aswell

Good luck with the build buddy

[daimlerman]

so if i get some valves from a 325 head and a schrick cam with a525e bottom end it should be a good one then?

You have the right idea there,of course you will have to let the machine shop enlarge the valve seats to suit the bigger valves.No pain=no gain be aware that the more lift to the cam the more ultimate bhp,but a more tempremental engine with a lumpy idle. I achieved 178 bhp using a standard 325 cam,and a shed load of torque

[cliffybabe]

daim r u running on super unlead or norm?? What air filter u running??

[daimlerman]

Ran my engine in on super,then one day I did'nt have time to queue for the pump so I filled up with standard unleaded.I checked the consumption over a month(about 1200 miles)and on super I gained about .25 mpg,so I decided it was not cost effective.I have a K@N cone filter,sat in a home -made heat shield.Being an old man,mpg is more important than bhp... on normal use,with me commuting to work(a 41 mile round trip on unclassified country lanes ) and my wife's 1 mile trip across the city,the 2.7 returns 34.5 mpg. The 316i youring,used in the same way,gives 32.8 mpg.... hence my current project to insert an M50 into a touring...

[cliffybabe]

good returns on fueling

[whipsey]

so if i get some valves from a 325 head and a schrick cam with a525e bottom end it should be a good one then?

You have the right idea there,of course you will have to let the machine shop enlarge the valve seats to suit the bigger valves.No pain=no gain be aware that the more lift to the cam the more ultimate bhp,but a more tempremental engine with a lumpy idle. I achieved 178 bhp using a standard 325 cam,and a shed load of torque

what sort of cost am i looking at for having the seats enlarged and how much would a new set of valves cost?

[Brianmoooore]

daim r u running on super unlead or norm??

The only reason to run it on super unleaded is if it 'pinks'. If it does when you run it on ordinary unleaded, then you will damage the engine, and, to avoid this, you need to use super.
If it doesn't 'pink' on normal unleaded, then there is NO advantage whatsoever in using super! It doesn't give you more power or more MPG; just a lighter wallet.

[daimlerman]

You will need to talk to your chosen machine shop!! As a rough guide,I paid £25 for a skim and was quoted £5 per seat for the valve mod (multiply by 12) valves are around £12 each new...Tuning costs... think my last head rebuild was about £350 all in... but some work you just cannot do yourself so smile cheerfully and pay up. Brian,your post confirms my findings with super,the small gain in mpg that I recorded is more than outwieghed by the extra cost.

[cliffybabe]

daim r u running on super unlead or norm??

The only reason to run it on super unleaded is if it 'pinks'. If it does when you run it on ordinary unleaded, then you will damage the engine, and, to avoid this, you need to use super.
If it doesn't 'pink' on normal unleaded, then there is NO advantage whatsoever in using super! It doesn't give you more power or more MPG; just a lighter wallet.

cheers brian

[whipsey]

oh and i nearly forgot my business partner is going to port the head for me as well

[daimlerman]

oh and i nearly forgot my business partner is going to port the head for me as well

Good idea!! Can he do the valve seat enlarging as well? Alpina achieved more by working on the exhaust ports..

[whipsey]

oh and i nearly forgot my business partner is going to port the head for me as well

Good idea!! Can he do the valve seat enlarging as well? Alpina achieved more by working on the exhaust ports..

thats a good point lol im going to have a word in his ear