'assembly' updating - what consitutes an engine again?

OK - We are all aware that under the update/backdate rule, when it comes to motors the assembly is considered to be the long block with the head and bottom end together.

What about the other components?

For instance intake manifold on a later motor has an additional mounting boss for a decorative cover - or additional support for a fuel rail. Does the long block = throttle plate to exhaust port, or could you use either part (provided they are otherwise identical)?

Or in the case that brought this question to mind. For my car early motors came with cast aluminum flanges (the part that bolts to the block or head with a 'hose barb') for cooling hose attachment, and later ones used plastic here. I have integrated my gauge senders into the older style aluminum flanges. Do I need to replace this with the plastic parts when I put the later Digifant motor in?

I can't convince myself that any of this makes any difference, other than I already have parts to use in one case.

Thoughts?

If you go by the common understood meaning of the term "long block" that would not include anything before the intake ports or after the exhaust ports.

This is a grey area.. I am not to familiar with the VW engine in question.. (though I should start looking into this since we are about to start running an old ITB rabbit). Does the manifold bolts to this plate.. so it is like a runner extension?

Sorry I was less than clear. The manifold is not an issue for me. There is a difference between CIS-E and Digifant manifolds - the Digifant one has mounting bosses and tapped holes on the outside to enable mounting of the fuel rail and fuel pressure regulator. But I have plenty of those available. I just mentioned it as an example.

The one I am trying to decide what to do with is the coolant flanges. Early cars had aluminum ones, later cars had plastic ones. If I use the aluminum ones, I have a set modified to fit my gauges/sensor already. If I use the plastic ones I have to make adapters to make it all work. I guess there could be slight differences - plastic may be ounces lighter - aluminum may last longer (or vice versa).

the aluminum bit should definetly last longer and disapate more heat. plastic should be more brittle and insulate heat.

I would like to see what some of the board members think of this :shrug: