Moving on with more pictures. The heads themselves clear the cover fine, enough margin at the top, no issues here:
And as a final step for now I have put the intake manifold back on. This does give a height issue as it will not allow the cayman cover to fit at the rear (cover angles down), not at the front. Overall it is just too high.
Not mentioned before, but the engine height chosen for this fitment was with the sump in line with the bottom of the car. I don't want to drop it as it seems a bad idea to have the sump as lowest part of the car...
Picture with manifold:
So to summarize this test, I think the two main concerns are:
- Breather connection on valve cover. It is also the head most rearward and moving the engine further to the front would be good.
- Intake manifold is just too tall.
The transmission can't move further forward due to driveshaft clearance. I currently have the 5.5mm spacer between engine and transmission which is what should fit regular S4 / RS4 flywheel / clutch combinations. There is also a 11mm spacer which is used on the V6 engines.... every bit could help here.
Manifold... hmmm.... the only alternative I have seen is the RS5 intake manifold. This is a simple (and cheap) plastic piece. As the RS5 is DFI it doesn't have injector holes, but the RS5 came with 'swirl flaps' in a separate part between head and manifold. In theory I could make a similar part without those stupid flaps but with injector holes. Height of that manifold is unknown to me, it seems to have a slope on it (lower at the front, higher at the rear), but not sure how it compares against the S4 one...