Inlet manifold Co flap broken off

[ainarssems]

I don't think it's ideal to run it with one flap missing, either have them all or remove all. That cylinder will be getting more or less air compared to other cylinders depending on rpm but the same amount of fuel as rest on that bank so could be running lean or rich and cause damage to the engine if too lean or cats and O2 sensors if too rich.

[spannerrash]

I've been trying to wrap my head around what effect having one long runner and 7 short ones would have on the engine. I honestly have no idea but I did think that each cylinders fuel requirements was determined individually. I could very well be wrong here but my understanding was that the exhaust manifold is divided into 4 separate tubes internally so that the o2 sensor and ecu can determine which cylinder has just exhausted and thus trim fuel accordingly.

I've ordered a used unit on the evil bay and will see what it is like when it turns up. I may still end up making a good one from the two but let's see what happens.

I'll keep you all posted and if I end up stripping them down I'll post my progress with a bit of a how too guide.

Cheers Frank

[ainarssems]

Originally Posted by spannerrash

I've been trying to wrap my head around what effect having one long runner and 7 short ones would have on the engine. I honestly have no idea but I did think that each cylinders fuel requirements was determined individually. I could very well be wrong here but my understanding was that the exhaust manifold is divided into 4 separate tubes internally so that the o2 sensor and ecu can determine which cylinder has just exhausted and thus trim fuel accordingly.

I've ordered a used unit on the evil bay and will see what it is like when it turns up. I may still end up making a good one from the two but let's see what happens.

I'll keep you all posted and if I end up stripping them down I'll post my progress with a bit of a how too guide.

Cheers Frank

O2 sensors do not work that fast they just measure average and trim fuel for whole bank, you can expect response time 0.5-2sec, in that time each cylinder in idle fires 5-10 times. Plus the glasses already in exhaust are mixing with incoming glasses.

[spannerrash]

Thanks Dean for the link.

It does look like it's been drilled for LPG though.

[Spanker]

Originally Posted by spannerrash

Thanks Dean for the link.

It does look like it's been drilled for LPG though.

Good spot. I should have read the description as it states that there too.

[spannerrash]

Just ordered this one from the US. Gonna be a pain as I had to use a freight forwarding company (shipito) as they wouldn't ship to the UK. I think it will work out at about £1500 landed which was about my limit.

[spannerrash]

I opened up my broken manifold and you can see hear clearly where she broke.

[steamship]

Originally Posted by spannerrash

Gonna be a pain as I had to use a freight forwarding company (shipito) as they wouldn't ship to the UK.

Ain't that the truth. I found a part only on a German site, and because they won't ship to the UK, I got someone in Germany to post to someone in Ireland, who will drive the roughly 10 miles to drop it off with me!

[ainarssems]

Originally Posted by spannerrash

I opened up my broken manifold and you can see hear clearly where she broke.

I am wondering if it would be possible to remove the plastic flap, weld the broken arm, then securely reattach the plastic flap.

[steamship]

Originally Posted by ainarssems

I am wondering if it would be possible to remove the plastic flap, weld the broken arm, then securely reattach the plastic flap.

Just looking at the photos again, isn't it a very unusual part to break? I always thought that it was just the plastic flaps that deteriorated over time, got brittle and broke off. Although, you could say he was 'lucky' in that there was no way part of the arm and the flap were going to drop into the cylinder, unlike small bits of plastic.