diesel engine, logical swirl flap fix?

[Wideboy]

i've been looking at the controversial swirl flap design on the E46 motors, this is a swirl flap for those that down know, it sits in each inlet manifold, all connected to a arm thats attached to a servo.
8670

the fault is that the flap made is made of week plastic that deteriorates and breaks down resulting in it going into the cylinder, or the 2 machine bolts come loose resulting in the flap and bolts going down into the cylinder. picture of a failed one
8669

Mej sent me a link to a company that provides blanking plates so you can take the whole assembly out and block the hole, but they are £14 + vat each (how about nooooooooo). been trawling the interwebs all evening trying to find sizes for them as i could get them made for free but couldn't find them. bloke on ebay is selling them individually for 6 quid so i could buy one and have it coppied, but.........
8671

this is what i cant seem to understand, I've not taken them out yet and had a look but to me, why couldnt you just take the two bolts out, remove the flap and put the assembly back into the manifold? :confused: or or cut of the arm?. am i missing some grand design plan here? can anyone see why that wouldn't work?

i know its not a car place but the BMW forums are full of crap

[Specialone]

Why are they there if not needed?

[Wideboy]

they lower the emissions slightly and i think they improve boost pressure a tiny amount, but most people have said they don't notice any difference when they're gone, nor have the emissions been flagged up on MOT's

[Bibio]

you could if you filled the hole where the shaft goes threw with JB Weld.

[Wideboy]

Well I was thinking not even gojng thay far, just taking off the flap and two machine bolts leaving the shaft there, only thing I can see it affecting is fueling but just having a shaft there cant effect it anymore than having nothing there what so ever. Going to have a closer look at them at the weekend, I reckon thread lock and some epoxy should suffice.


Just all seems odd that peoples first reaction is to pay 60 quid on parts that's not even authentic BMW parts, when you don't have to. Some have even paid 400 quid for a new designed manifold from hem that gets rid of the swirl flaps completely

[Dicky Ticker]

If I read this correct they are on induction air?[Sorry don't know that particular engine] and would probably assist in the air atomised fuel mix in the chamber giving better ignition,cleaner and less carbon deposit in the chamber with a even air intake to all cylinders.Yes the engine would probably run reasonably well without them but more than likely a lot better with them.
Lots of engines have bits on them that they can run without but in my experience they are usually there for a good reason,be it efficiency,emissions,cooling,air fuel mix whatever.

[Wideboy]

Any idea on how to better fix them to the arm? I'm thinking thread lock and epoxy over the head and bottom of the machine bolt. They're the only thing I'm particularly worried about going through the system (for obvious reasons). I reckon the plastic breaking up would just pass through

[Dicky Ticker]

Turbo blades are metal and can cause severe problems when they break up but as these are plastic I would imagine that any plastic fragments would melt and burn off due to the heat of the ignition,possibly why they are plastic in the first place.I dont know how they are fixed but providing that they are secure what is the problem as they are a static fixing

[kwak zzr]

buy my petrol one it doesnt need this mod :)

[mikerj]

Turbo blades are metal and can cause severe problems when they break up but as these are plastic I would imagine that any plastic fragments would melt and burn off due to the heat of the ignition,possibly why they are plastic in the first place.I dont know how they are fixed but providing that they are secure what is the problem as they are a static fixing


Swirl flaps breaking have caused major damage to numerous BMW engines. They don't just start breaking up into tiny bits, the whole flap parts company with the spindle and gets ingested. It's a very well known problem, and not only on BMWs.

The flaps are only effective under very light load (low boost) conditions where soot generation is more prominent. Removing them may have a small impact on economy and driveability at low speeds, but most people don't notice a great deal of difference.

[Fade]

As mentioned above they would increase tumble into the ports which gives better fuel/air mixture giving better combustion.

If they partially block a portion of the intake port then using them to increase the gas velocity at lower engine speeds would give torque gains.

As a Fix a PROPPER permanent thread lock (not some ****ty stuff you buy down halfords) to fis the screws the plastic if it goes will melt/burn off.

[barwel1992]

have the flaps made up out of metal then rivet them on to the arm ....

if thread locking use 648 PS to remove you will have to use alot of heat

[Wideboy]

What would you recommend as the ultimate thread lock?

[Wideboy]

have the flaps made up out of metal then rivet them on to the arm ....
that would made the risk wors and rivets wouldnt hold

[barwel1992]

rivets wouldn't hold ? wings on race cars are riveted and subjected to over 150mph wind and force im sure they could hold some small flaps

see other post for locktite to use

[Wideboy]

Because the rivet would have to be tiny as the bolts are only about 3mm, the swirl flap unit its self is only 22mm in diameter, then if that fails you'd have same metal plate instead of a plastic one going into the cylinder :lol:

Cheers for the thread lock

[barwel1992]

Because the rivet would have to be tiny as the bolts are only about 3mm, the swirl flap unit its self is only 22mm in diameter, then if that fails you'd have same metal plate instead of a plastic one going into the cylinder :lol:

Cheers for the thread lock

22mm ....... hardly worth having them there

and 3mm no wonder they fail

id get rid

[Viney]

Make some out of wood

[punyXpress]

[QUOTE=barwel1992;2501767]rivets wouldn't hold ? wings on race cars are riveted and subjected to over 150mph wind and force im sure they could hold some small flaps
[QUOTE]
Bet wind speed in the inlet throat is a bit more than that.
Only solution is removal of the offending article.

[barwel1992]

[QUOTE=barwel1992;2501767]rivets wouldn't hold ? wings on race cars are riveted and subjected to over 150mph wind and force im sure they could hold some small flaps
[QUOTE]
Bet wind speed in the inlet throat is a bit more than that.
Only solution is removal of the offending article.

i said over 150mph closer to 250mph taking wind speed + car speed

[mikerj]

[QUOTE=punyXpress;2501820][QUOTE=barwel1992;2501767]rivets wouldn't hold ? wings on race cars are riveted and subjected to over 150mph wind and force im sure they could hold some small flaps


i said over 150mph closer to 250mph taking wind speed + car speed

Because race cars often run in 100mph winds? :D

The pulses in an inlet tract caused by the valves opening and closing are extremely strong, it's a completely different environment to a continuous 150mph wind. Race car wings also tend to be held on by more than two tiny rivets...

[barwel1992]

[QUOTE=barwel1992;2501943][QUOTE=punyXpress;2501820]

Because race cars often run in 100mph winds? :D

The pulses in an inlet tract caused by the valves opening and closing are extremely strong, it's a completely different environment to a continuous 150mph wind. Race car wings also tend to be held on by more than two tiny rivets...

no i was refering to a car going at 200 with a 50 wind :rolleyes:

and for a 3 ft wing there are 4 rivets holding the lip on ..

[Stonesie]

The later flaps are a 1 piece plastic design so they will get chewed up and spat out if they fail, but the spindle is also a larger diamiter, it is the metal bits that cause the damage and the best way of pre-empting the problem is to remove them and fit blanking plates.

[Lozzo]

Spend the 14 quid +vat each on the blanking plates. I wouldn't risk anything more getting ingested and possibly wrecking the engine when I knew there was an affordable solution that bypassed the problem before it started. You're looking at spending 60 odd quid to save paying a grand on a replacement engine.