Viva hc 2.3 cylinder head on 1.3 block??

I may be missing something here, but the 1.3 is a straight OHV four-cylinder while the 2.3 is a 45-degree OHC slant-four? I can't imagine they'd switch over, they're very, very different engines.

Per Wiki -
The engine features four inline cylinders inclined at an angle of approximately 45 degrees (hence the name), and this is because Vauxhall had originally planned to develop a whole family of engines all built on the same production line. There was to be slant four and V8 versions in both petrol and diesel versions, designed under the guidance of Vauxhall's then chief engineer, John Alden. Although several diesel 4-cylinder and a V8 petrol engine prototypes were built only the 4-cylinder petrol made it to series production.

Paul H

Absolutely no chance at all, too much is different. It would be less work to swap the whole engine, gearbox, front subframe and rear axle, and then fit the bike carbs.

Ahh cool thanks, well yea thats what i was thinking with the bore sizes being different theres a greater possibility of blowing the head gasket, but if it were a copper gasket sealed properly it would tecnically be a slightly larger litre but i doubt alot, but shouldent blow it?! the heads i have found on ebay don't look like they should have over head cams, but ill have another look. The other thing is whether all this would acctually increase the performance by much or just end up costing teice as much in fuel ahha

The waterways. And the dowels. As I found to my cost...

Sounds like you've got your answer, but just incase you're interested, increasing the size of the combustion chamber won't increase the engines capacity. The capacity's measured by the volume that the piston sweaps through, so is the cylinder bore area, multiplied by the stroke, regardless of the chamber volume. A larger chamber volume would actually decrease the compression ratio, which would hurt performance and economy quite noticeably.

As for slanted engines, as well as the height advantage, (good for center of gravity, and low bonnet heights.) it can also make designing the cooling and oil systems more straightforward, as you know where air will rise to and where oil will drain. It can also help with manifold lengths. Most engines have to settle for much shorter inlet manifolds than would be ideal because of space, but leaning the engine right over to one side of the engine bay can allow for longer inlets. So basically it helps in a few ways if you're designing a car/engine, but there's no real advantage to leaning over a currently vertical engine (bar space).