Putting my top end back together I noticed my HG kit came with 8 round seals, about an inch in diameter, and about 3/8 thick. No idea what they're for.

And just wanted to float this. I'm pretty sure its been discussed before, but not sure where to find the thread. Has anyone either shortened the intake venturis or added a spacer to the upper plenum to create more space between the venturis and the plenum. It seems there isn't much room there. I understand its to quiet and smooth the incoming air and that changing the stack height by either method would probably have a negative effect on off idle acceleration. But dammit I'm curious.

I'm prepared for the inevitable "wont matter, the ports are too small" answer.

 

The Brits who wring every hamster power out of the mighty engine do mod the tubes.

And a good mechanic always has parts left over.

 

"Unused" is the name of that set of seals.

Notice how many pop right up about engine performance? Zero! Know why? Cuz their aint anybody here.....golly gee whiz.

Search the web bud, there's a ton of "American" info on tuning the RV8 including racing it. I'd point you right to it but I like my privacy....sorry. Some serious motor **** and a knowledgeable bunch of members who are gear heads to the very end.

Loved your question. Zip is the answer. You can't modify it without ditching the Rover FI setup....in your case it's the 14CUX. You can chip the box (1) but it's really a huge waste of money when you can custom build a controller or buy one already programmed with your tune mods.

Find the site I'm talking about and you'll be in a slice of heaven......

 

They're finger splash guards for rhino lining your nails.

 

Actually, various sizes can be fitted, and maintain stock plenum height. These "super trumpets" allow air flow increases speed as the neck narrows and helps flow around the intake bends. The Rover V8 has plenty of mods for it, like ihscouts mentions. If you look at pix of older Rover carb setups you'll see all sorts of manifolds.

Some claim that a 3/4 trim for all increases performance when WOT, not so much HP but smoothing out. The stock trumpets are two lengths to compensate for the intake, which has longer and shorter passages.

As with most engine mods, a single change is frequently held in check without more mods of something else, like cam, etc. And you can easily get the the point where stock electronics has reached the edge of what it will adapt to.