Engine casing discrepancies

[SpookDog]

Is it normal for two casings to be different? Specifically the inlet porting? The right side case doesn’t match the left by about 8mm! It’s an old 3bn that I don’t know the history of (eBay). I’m guessing that they two different year casings.
Is it best to match them or is it normal?..
Cheers

[Calum]

Yeah, they aren't well matched out the factory are they

There is a lip on the cases at the inlet. But they are fine everywhere else.

I presume this was done for a reason.

[declan]

@SpookDog it's fine from what I've heard but some file it down

[SpookDog]

Just to embellish a bit. These are 3BN 01 cases. I have some 3BN 03 cases that are totally different. The inlet port that ‘ups into the barrel’ doesn’t have the step, but does have a ‘flaired up step’ that I guess directs gas flow up into the barrel port. I’m just wondering how many different variations of 3BN engines there are?
I’m guessing that the 01 & 03 numbers are the year?
Cheers guys

[SpookDog]

Sorry! The ‘flaired up step’ is just above the crank. Not a step in the casing. It’s more like a spoiler or a ramp...

[Calum]

A picture says a thousand words...

[SpookDog]

I agree! The bits I’m on about are internal though

How do you post upload pics from a phone. Do you still need to host the pic?

[declan]

@SpookDog yeah you host the pic then copy the picture address then. Press the picture icon just above when you are typing a post then paste the address into the highlighted section

[SpookDog]

@SpookDog said in Engine casing discrepancies:

Is it normal for two casings to be different? Specifically the inlet porting? The right side case doesn’t match the left by about 8mm! It’s an old 3bn that I don’t know the history of (eBay). I’m guessing that they two different year casings.
Is it best to match them or is it normal?..
Cheers

I know it’s an old post, but I’ve only sussed out pics recently. Check out the casing join inside the inlet!...
What say yooz?...

[SpookDog]

@SpookDog

Seriously! That’s not normal is it? I ended up cutting and filing back the right side casing to match the other side...