m30 head rebuild and porting

[constantproject]

i need to change my head as soon as the ice melts for more than a few days and would like to port/polish and cam my m30 so i have a few questions for the masses


does anyone have any measurements and or flow numbers for their ported(probably polished as well) m30 head?

i will be getting the head (already have a second) inspected, a valve job, a cam( open to suggestions for an aggressively driven street car...please ), and depending on what they look like, new rockers.


are there certain companies i should avoid parts/machine shop -wise?

and going with my first question, where would i go to find such people who would divulge their dimensions...who dont do it with a cnc because i cant lol(i dont need to hear the dont do it yourself shpeel, i know how to do it, just not how big i can go safely for this engine)

[ClarkWGriswold]

Can't help just yet as I just dropped off my M30 head yesterday to be cleaned up so that we can start the porting process this month. Working the head over in preparation of the upgraded 745 turbo install. If the flow bench is open I will get a stock base line so that we have some thing to compare against the finished product and I will try to get a photo tour of the process once I get the head back next week.

[constantproject]

awesome dood, keep me updated please! i love to watch other builds because it makes the hamster start running again and i come up with all kinds of other ideas(the kind that make me wish i could draw worth a crap lol) and gives me more of an exact direction i want to go. i dont want to copy/imitate but i do need somewhere to start, and i appreciate any help!

[constantproject]

anyone else have any tips or tricks or anything?

[Binjammin]

You're not going to pick up much, as the intake manifold is a large restriction as well. Best advice would be to gasket match it and keep the porting as uniform cylinder to cylinder as possible. Stick mostly with the polishing unless you have a lot of experience in porting.

[NY Bimmers]

putting a cam in an m30 isn't worth it. Like bin said, the intake is a major restriction, if you can't get more air into the motor, anything you do will be pointless. HP for dollar on adding a cam makes it not worth it.

[constantproject]

between porting and a cam i should see a few hp, but i know it wont be alot.

is the intake the biggest restriction because the runners are small? because they looked plenty bigger than the intake ports when i had it off last fall... does anyone know how much i can take out of the runners and not have to worry about cracking or heat soak(any worse than it already is anyway lol)

the one thing i noticed as a very probable restriction is the throttle body being too small for the engine in general, i have heard a mustang tb is useable...is this correct? i would think as long as i could bolt it up and put the proper tb sensor on it it would work yes?

with a tb, cam, p/p, it should net me some relatively inexpensive hp and torque, and maybe some mpg if i can keep my foot out of it...which isnt likely lol

but i do need limits as to how far i can port both head and manifold
also, does anyone run an oil catch can on their m30? i was thinking about moving the port on the valve cover to accomodate one better but was curious if anyone had a different idea of putting one in

[Binjammin]

The throttle body isn't a restriction, no more than anything else in the intake tract. Going to a larger throttle body you lose resolution in the pedal action, it makes it more on/off than gains you power.

The intake isn't so much of a restriction due to port size as it is due to runner length and layout. Long, twisted runners and a small plenum.

[constantproject]

long runners typically add up to low end torque but restrict top end, which describes this engine to a tee lol. but i dont really appreciate the runner layout no matter what. it looks nearly impossible to port or polish unless i cut it, and then welding it back together appears near impossible as well if i want to keep the runners separate.

the only other manifold options i have seen are for turbo applications where runner length is kind of a moot point unless your building a race specific engine.

i was thinking maybe a tube fabricated aluminum "log style" manifold might be a legitimate option and, depending, decently priced to make/have made. the few manifolds i have seen fabbed up on here were for turbo apps, im not ready to go turbo yet so those arent really an option.


i might play with paint tonight at work and see if i can show you what i mean.
if i can come up with a reasonably affordable fabbed mani, then the larger t/b and cam would make more of a difference.

im not looking for a race engine, but i want to play with this engine before i get pissed off at mediocre power and put in a v8(most likely not a bmw mill).

[MattMc1]

Almost about to start the work on my head now that the block is sorted and will hit the machine shop some time next week.

So I will be watching this with interest. Porting and polishing is a bit of a black art in my book.

I will have 1mm oversize Valves and a Cam to suit the build, though the Cam is still been discussed, along with single billet rockers arms and springs to suit.

Regards M

[darknezz7]

sounds to me like you need millers new m30 turbo intake (it goes to the drivers side for inter cooler setups) and the miller maf and chip all 3.5in intake with a k&n filter shielded from the engine. total free flowing intake.

that would take some SERIOUS advantage of porting, cams and bigger free flow exhaust.

:drool: :drool: :drool:

hopefully thats what I will get to do one day, then the full engine build and turbo.

oh but the m30 will be in a plastic bumper 2dr e30 :devillook

[Binjammin]

sounds to me like you need millers new m30 turbo intake (it goes to the drivers side for inter cooler setups) and the miller maf and chip all 3.5in intake with a k&n filter shielded from the engine. total free flowing intake.

that would take some SERIOUS advantage of porting, cams and bigger free flow exhaust.

:drool: :drool: :drool:

hopefully thats what I will get to do one day, then the full engine build and turbo.

oh but the m30 will be in a plastic bumper 2dr e30 :devillook

Flipping the throttle body from one side of the manifold to the other will potentially give a cooler air charge and make charge pipe routing easier with a front mount intercooler, but it's still the same runner and plenum geometry, and I don't recall hearing miller announcing a new manifold.

[stoney85]

if you have the skills and ability, why not make an intake to suit the M30

is there inlet manifold flanges available for these on the net somewhere?

Why not build one up, like most people do for a turbo setup, but just pay a bit more attention to runner length and plenum size before putting a throttle body on it, and if you keep the setup simple, you could still use the stock ECU with the W.A.R chip or similar installed to tune it.

Obviously a lot of tuning of the fuel maps will be required after a large change of air is available to the engine, plus a nice polished aluminium intake would look nice on an M30

And if designed with some strength/bracing in it, it'll be usable for a turbo setup aswell

[MattMc1]

Or this :devillook

http://img.photobucket.com/albums/v328/awill4x4/Intercoolers/Laminova/Toms%20BMW%20Laminova/TomsBMW3resized.jpg

http://img.photobucket.com/albums/v328/awill4x4/Intercoolers/Laminova/Toms%20BMW%20Laminova/TomsBMW1resized.jpg

[constantproject]

sounds to me like you need millers new m30 turbo intake (it goes to the drivers side for inter cooler setups) and the miller maf and chip all 3.5in intake with a k&n filter shielded from the engine. total free flowing intake.

that would take some SERIOUS advantage of porting, cams and bigger free flow exhaust.

:drool: :drool: :drool:

hopefully thats what I will get to do one day, then the full engine build and turbo.

oh but the m30 will be in a plastic bumper 2dr e30 :devillook

:alrightthats what i want to do, but 800+ for that kit is kind of a stretch for me right now, a couple hundred to a friend to let me use his welder and some tubing would be more fun right now anyway lol it would make me feel like i am accomplishing something haha


Almost about to start the work on my head now that the block is sorted and will hit the machine shop some time next week.

So I will be watching this with interest. Porting and polishing is a bit of a black art in my book.

I will have 1mm oversize Valves and a Cam to suit the build, though the Cam is still been discussed, along with single billet rockers arms and springs to suit.

Regards M

excellent keep us updated


if you have the skills and ability, why not make an intake to suit the M30

is there inlet manifold flanges available for these on the net somewhere?

Why not build one up, like most people do for a turbo setup, but just pay a bit more attention to runner length and plenum size before putting a throttle body on it, and if you keep the setup simple, you could still use the stock ECU with the W.A.R chip or similar installed to tune it.

Obviously a lot of tuning of the fuel maps will be required after a large change of air is available to the engine, plus a nice polished aluminium intake would look nice on an M30

And if designed with some strength/bracing in it, it'll be usable for a turbo setup aswell


this is what i was talking about, in theory not too hard to do... in reality im nowhere near anyone i knew with some sort of shop and a tig welder lol. and my thinking was either thick wall aluminum or stainless...that would look even prettier under any hood



Or this :devillook

http://img.photobucket.com/albums/v328/awill4x4/Intercoolers/Laminova/Toms%20BMW%20Laminova/TomsBMW3resized.jpg

http://img.photobucket.com/albums/v328/awill4x4/Intercoolers/Laminova/Toms%20BMW%20Laminova/TomsBMW1resized.jpg

:eek2:eyecrazy

where are you, you gots skeels, i know it would cost a lot to have it made but i may be willing to spend some(i dont have alot lol) dough to have you make it... i think your the one i looked at a bunch of your work and all i could say was dayum...

[MattMc1]

:eek2:eyecrazy

where are you, you gots skeels, i know it would cost a lot to have it made but i may be willing to spend some(i dont have alot lol) dough to have you make it... i think your the one i looked at a bunch of your work and all i could say was dayum...[/quote]


HB (http://www.advancedhbintercoolers.com/) <---- Link

[constantproject]

pm'd... bump for any other input?

[Brody @ Miller]

Here is a flow chart for our heads vs. stock. You can pick up power especially with a proper cam with that intake manifold. While it isn't gods gift, it does its job well enough to satisfy a decent amount of power N/A.

http://millerperformancecars.com/files/M30%20Flow%20Chart.pdf

[MattMc1]

Here is a flow chart for our heads vs. stock. You can pick up power especially with a proper cam with that intake manifold. While it isn't gods gift, it does its job well enough to satisfy a decent amount of power N/A.

http://millerperformancecars.com/files/M30%20Flow%20Chart.pdf

A little far for me, and only stock valves but a nice increase none the less.

Graph printed for reference.