Hiya...new to minis so haven't been able to add anything to the site really, I'm still in a learning mode.
However I know a bit about the good old VX lump so thought I'd have a post here, it may even be of use to you with a bit of luck
I love the project you're undertaking..top man with the heart of a lion to be honest, can't wait to see the finished beast. Really enjoyed reading the progress so far.
As for the VX, well at the moment I also have a Caterham Vauxhall HPC with a Swindon VX 16V motor in it, it is quite heavily modded and dry sumped but feel it may be overkill in a mini.
In my last 7 again another VX albeit a standard unit with 175bhp breathing through 45s I needed to get a few extra horses for the sprint championship I was languishing in
I indeed opted for the cheap-ish route which was the QED 420H cam profile which was very well priced on an exchange basis with my originals.
This as you know retains the standard Hydraualic lifters and indeed are fitted without the use of verniers etc.
The big cost was the ECU to glean the most from the swap. I plumped for a 3D DTA unit as I have a friend who is very good at mapping them. I also bought the throttle potentiometer and uprated rod bolts from QED at the same time.........the latter is a must in my opinion.a bit of insurance.
Anyway upshot was it made 180 at the wheels at SGT rolling road in Northich as opposed to 160 beforehand.....well impressed for an outlay of less than a grand and reccomend that route as a starter.
Car drove like a dream and had NO flat spots. In a way it drove better than my current Swindon motor as this one is "cammy" and only really starts squashing your face after 5000 rpm,below that and the the other other car would easily match it.
One huge advantage you'll have over me (hopefully) is your induction set up. I assume your TB's will fire directly into the ports at 90 degrees. With the dog leg setup neccassary on the Caterham installation this is impossible without going to the huge expense of DTHTB's and remaking a bonnet for the exit of the induction.................this alone will give you extra power.......in the region of 20 bhp if you can get a straight run.
In the meantime go on to our club site "the Lotus 7 club of GB" and go on to Blatchat. Do a search on VX 16V and far cleverer guys than me will keep you more than interested in what they've done to their XE, some seriously knowlegable guys there on this subject.
All the very best,
Kenny