Intake manifold to change or not to change

[stewart in slc]

Are there advantages to removing the log intake and changing to a later intake manifold?
Are some years more beneficial than others?
thanks
stewart
528i m90 3.5 stock l-jet

[T.Hanson]

Haven't heard of changing the log, but some change ribs. I think those from 320i (?) are shorter, offering more torque.

Too bad I'm a pragmatic old grouch. 80 at the bottom of a ramp bone stock. If that's not enough to get tickets, buy a kart and go racing.

[GripGreg]

Stewart, I've noticed that T-Han stumbled & everyone else on this website says the intake runners that make a differance are the ones from any 320 from the years '77, '78, & '79 only. The main thing I get is to make sure the engine is the 2.0 litre, NOT the 1.8 litre engine.
The intake runners are fatter & longer. More air in? After that I can't help ya. Greg

[Peter Florance]

Stewart, I've noticed that T-Han stumbled & everyone else on this website says the intake runners that make a differance are the ones from any 320 from the years '77, '78, & '79 only. The main thing I get is to make sure the engine is the 2.0 litre, NOT the 1.8 litre engine.
The intake runners are fatter & longer. More air in? After that I can't help ya. Greg

Longer. Moves tq peak to lower rpm. You have to remember that it's not just larger smaller issue. At certain RPM's resonances occur in the intake, favoring those areas. But nothing is free; it probably hurts top end a tiny bit. I have them on the US car and top end is still pretty good.

[Brian Smith]

I think that since stewart has an M90 3.5 liter motor, he might be wondering not about just changing the log-style runners, but changing to the later m30b34/35 style manifold.

I'm not sure if this is a consideration, but I can tell you for sure, Stewart, that it makes accessing the cold start injector much more of a pain!

I think there may be potential clearance issues with the brake booster, but I'm speaking strictly from internet overhearing swap considerations, and probably mixing my e28 memories with e12 memories...

How about instead a custom dual AFM arrangement with a new log to improve flow distribution upstream of the log instead of concentrating on the path from the log to the intake valves?

Another theory - why not take advantage of the crossflow head and move all the intake related junk onto the driver's side of the engine bay, visually cleaning up the valve cover area and perhaps getting rid of the igintion wire crossfire bundle, making room to also allow visual access to the exhaust manifold/header area?

[Pete K]

In case you're not in the US or (by some chance find one) those intake runners are also off the early 4 cylinder 520i (the one with Kuggelfischer injection).

Cheers

[Odometergears]

If you want I have a whole log and runners with throttle body in a box ready to ship.

Greg, I am sorry but if you want these things back, it's time to clear up our business. I still have your cluster that is fixed and ready to go. The runners will go to whoever wants them at this point. $100 firm. plus shipping. We are close to a year waiting on you.

The 320i runners are attached to the log and ready to go on any m30 engine.

The disadvantage of logs vs solid intake is just that. All the joints. If you don't seal up all the connections, you will have a vacuum leak. I do have an extra B34 intake also. Same cost if you want that one.

Call me, either of you.

Jeff Caplan
Odometer Gears Ltd
757-593-3478