Since it seems to be difficult to find this information anywhere in these forums, I wanted to start a thread with this title to help those of us who are still uncertain!

I'm working on an engine rebuild for my daughter's R56.

Based on what I have seen, the cylinder numbers start from the timing chain side with 1-2-3-4. Is this correct?

I'm not sure about the firing order either but I know it's not 1-2-3-4!

Can several people confirm both of these please? For me and for others in the future?

Thanks!

 

Yes, typically, cylinder count starts at the front, or timing chain, side of the engine.

Usually, 4-cylinder engines have a firing order of 1-3-4-2

 

^Correct, double checked it in the Bentley manual. It would be tough to get the plugs connected wrong, though - not like the old days with a distributor and plug wires.

 

Is the timing chain on the right or the left when you are standing in front with the hood up?
In North America the drivers or the passengers side?
I am thinking the timing chain is on the passengers side but am not sure.

 

chains on passenger side

*fire order 1-3-4-2

**1 & 4 move together, as do #2 & 3

 

I think you meant to say 1&3 move in pair and 4&2 move in pair. When I pull open the heads and turn the crank I when flywheel is at 0 or 180 position, 1,3 are same height, then 4,2 are same height.

 

This is posted in a 2nd gen R56 section.. so you should be talking about an N14 or an N18. Both of these are flat plane crank engines and as such move the 1/4 then 2/3 pistons. Look up any 'google' image of a "N14 block" or N18 and you will see exactly what i mean.

 

Thanks for the clarification. Just a week ago I attempted for the first time ever to do a head job. And after I pull the head out, turning the crank and looking at the pistons move, I observed 1&4 and 2&3 align with each other in terms of "movement", not talking about firing order, just the way they move, and by align I meant at 0 degree and 180 degree flywheel locking position. So that's why I thought 1 and 4 go together as 2 and 3 do the same. Again, not firing order, just talking about the way these pistons move and end up at two different crank locations.

 

flat-plane 4cyl crank = 2 cylinders move at the same time & order is 1&4, 2&3 ..this goes for ALL N14 and N18 motor & N12

*Flat-plane cranks are by nature balanced better and can rev higher as result. A crossplane crank WOULD have a 1,3,4,2 order and fire at 90 degree crank intervals by comparison (1 piston/cyl at a time).

 

no shortage of weird about French motors

 

Um....


As stated, the correct firing order is 1-3-4-2. Yes, the N14/N18 is a flat plane engine (most 4 cylinders are). That means that 1/4 and 2/3 are at the same physical location, but their cycles are 180 degrees offset. That means when cylinder 1 is on an intake stroke, cylinder 4 is on a power stroke. The two pistons don't fire at the same time. If they did, the engine would "lope" like a Harley.

The proof is in the camshaft. The lobes for 1/4 are 180 degrees apart. They are 90 degrees offset from 2/3.

 

This is great info. Always something new to learn. Thanks I-forge-kc

 

yeah thanks for that - ive been drinking too much juice..dont know the difference between 4cyl and 8 any more lol

 

Thanks for the good info

 

You are correct. The timing chain on my R56 is on the passenger side of the car. If I am looking under the hood facing the front of the vehicle, it is on the left hand side.