Converting AAN to ABY spec

[Rusty]

Just looking at what's needed to convert an AAN engine to ABY spec. We know from this thread and this thread and this thread.

Ignoring the cylinder head for the minute and off the top of my head...

• Front pulley and damper
• Flywheel
• Engine mounts, incl. snub
• Sump
• Breather system (this isn't an issue for me but will be on a stock car)
• PAS pump, belt and bracket
• Water manifold
• Cam cover (breather return outlet is different but can be swapped)

Anything else?

I'd like to compile a list of things needed to do the conversion, as it'll be a useful resource

Obviously most of the metal bits are on the car, but it's things like gaskets,. nuts bolts etc. that would be required to do a smooth conversion.

[Rusty]

Parts list

2x Sump gaskets
Sump wing gasket
Head Gasket
Machined lower cambelt pulley
Timing belt
Water pump
Flywheel bolts
Flywheel
Clutch
Rear main seal + gasket
Front main seal + gasket
PAS belt
Alternator belt
Oil filter housing gasket
Oil pump gasket
Thermostat housing seal

[Rikki Kitto]

Don't forget to get 2 gaskets for the sump, they sandwich the metal bit and if you take the side bit off the sump you need a gasket for that too

[driftin jo]

If you are going to use a dual mass ABY flywheel / clutch assembly you will need
the longer ABY location dowels for the bell housing also.

[mcandmar]

Thermostat outlet is different, as is water rail on the head, and i think the dipstick tube too. Also alternator / pas pump mounts.

[Rikki Kitto]

Cam cover

[driftin jo]

he said "Ignoring the cylinder head"

[Rusty]

I did but I guess we can add all that in anyway

Cheers for the replies

Not a problem with the flywheel for me I'll be fitting a lightened 3B / 7A or Ally one, depending on how brave I'm feeling, along with a new clutch.

[Error404]

Best off getting a full head and bottom end gasket set mate

The front pulley is quite a bit bigger on the ABY and also you will be running a much ligher flywheel so you probably should get it balanced. then if you are doing that you're only a couple sets of bearings, a hone and a set of rings away from rebuilding your ABY

[Rusty]

ABY is likely to need a rebore due to bore wear at 172k and won't know that until it's out. Rebore and pistons is £££, loads more than a decent condition AAN. Other than keeping the original engine number, the internals and block are identical, so there's no reason to get overly excited about things, other than the purist in me... but then I've changed enough things that someone like Fatty would have a coronory over

[s2driveruk]

ABY is likely to need a rebore due to bore wear at 172k and won't know that until it's out. Rebore and pistons is £££, loads more than a decent condition AAN. Other than keeping the original engine number, the internals and block are identical, so there's no reason to get overly excited about things, other than the purist in me... but then I've changed enough things that someone like Fatty would have a coronory over

is the oil pressure good on the ABY...you may get away without going oversize...i did on my 3B (heh, just noticed that 3B with a typo on key 3 becomes £b...how true )

[Rusty]

Oil pressure is perfect - 2 Bar warm idle, 4.5 Bar when running - it's the compression that's the issue, one cylinder is down by 2.5 Bar. Still runs well and is making over 350bhp with no obvious smoke other than on cold start. However, idle is a bit rough and it chews a bit of oil.

ATEOTD, I'll be happier with some rods and a new clutch in there and a straight swap is easier than taking it out, rebuilding and putting it back in, as I don't have a garage and will need to do it in a weekend or at most a week. Depends on how much I bend someone's ear to borrow their garage.

[Error404]

£600 for a rebore and new Wossners, add a set of bearings and I guess its the same price as an AAN, but of course spec creep will set in, I know it has with my build My conern with my AAN to ABY spec engine conversion was the balance, so I took the decision to open it up and do it all once and for all. I guess if you need the car every day that changes matters somewhat.

[Rusty]

Was quoted a lot more than that for a rebore and pistons...

Trying to decide what the best way to go is, as I'd like a decent clutch on whatever goes in, and a set of rods is going to be a good plan too

[mcandmar]

I'd say rebuild is the way to go Andy, any replacement engine is only going to buy you time before your back at square one. I say budget for rods/pistons/machine work and do the rest yourself, that way you not only get a new fresh motor but an uprated motor ready for future mods. ..you know you will want to.

Or you could do it the least cost effective way like me, buy another engine to rebuild and chuck half of it in the bin and start again