M20 manifold air flow into ports seem odd to me

[Chuckcruzin1986]

I have been toying with the idea of building a new intake manifold and noticed that the intake air flow is 90 degrees from the mounting surface BUT when you look down into the port, it seems like the manifold should be at 60 degrees....?????

There is a fairly sharp turn as the air leaves the manifold and goes into the head. It might be that they needed to do this to be able to locate the injectors.

Am I missing something? Frankly I was shocked when I realized this is happening.

Thanks, Chuck

[SpecM]

...and now you know why people swap in m50s

[nando]

have you looked at a B25 manifold? it's a little smoother. The B25 manifold is actually a great design from a factory, cast manifold standpoint. Most of the M20's torque curve from 3k-5k actually comes from the manifold design.

the B27 manifold was never really meant for high power. the angle of the ports probably didn't matter that much.

...and now you know why people swap in m50s

thanks for that useless post.

[SpecM]

thanks for that useless post.

sure thing

I know m20b25 manifolds flow pretty good for what they are, its a good design

they don't flow like an m50 manifold, but then again that's the point of updating engine designs

[nando]

M50 manifolds are completely different; shorter runners, different helmholtz tuning, different everything. Saying it flows better doesn't mean anything.

[T Verdier]

So it's a b27 intake? Your buliding a custom intake for you eta?

[Mfever]

if your all for the 24v motor... why even come into the m20 subforum? honestly im getting sick and tired of people bagging on the m20 and praising m50s and what not. I've got nothing against the 24v motor, hell i would one day like to try it in an e30 but please stop pushing people and saying the m20 is garbage because it really isn't.

[SpecM]

if your all for the 24v motor... why even come into the m20 subforum? honestly im getting sick and tired of people bagging on the m20 and praising m50s and what not. I've got nothing against the 24v motor, hell i would one day like to try it in an e30 but please stop pushing people and saying the m20 is garbage because it really isn't.

I didn't say it was garbage

I have an m20 in my e30 and I love the engine

maybe my first comment was a bit hasty, but I think it's begine taken out of context

[nando]

your first comment was stupid and pointless. There was no context.

[stumble_t]

have you looked at a B25 manifold? it's a little smoother. The B25 manifold is actually a great design from a factory, cast manifold standpoint. Most of the M20's torque curve from 3k-5k actually comes from the manifold design.

the B27 manifold was never really meant for high power. the angle of the ports probably didn't matter that much.

So are you saying you can swap a b25 intake on an eta/seta? If so will it be an improvement?

[nando]

well you can but the ports won't match the eta head so you'd have to port match everything.. not sure how worth it that is when you still have a single cam and ~5k redline. it's a direct fit on the seta though.

[stumble_t]

interesting. Do you think it would be an improvement on a seta?

[nando]

without supporting mods (like all the other "i" stuff), no.

[SpecM]

interesting. Do you think it would be an improvement on a seta?

^ like nando is saying, w/o other b25 bits its just noise

but with a complete b25i settup, like cam/springs and throttle body and afm, its a huge huge difference

your first comment was stupid and pointless. There was no context.

fair enough

[Chuckcruzin1986]

The engine is a 325i

So it's a b27 intake? Your buliding a custom intake for you eta?