Hi all, new to this forum but not to messing around with cars.

Have been looking into GTi-6'ing my 2.0 16V XSi recently (it's a XU10J4R engine). From what I've read on here, there seems to be quite a few differences between the J4RS (6) engine and mine, but hopefully enough similarities to allow my rather fixed view on the extent of my upgrade, which is planned as:
- swapping inlet and exhaust manifolds (and the cat of course to join my XSi centre section). (I've read the pictures write-up on how to swap the inlet manifold.)
- possibly fitting camshafts from a 6 (but not messing around with the bottom end at all)

I do have a couple of questions about some specific things though:
- can I just fit the 6 camshafts to my head, or will the valves hit the pistons as a result of the extra 0.9mm lift (I have 360 thou lift on mine, and 395 on the 6)? (I am hoping not, because the CR of my engine is lower, so I am assuming there is a bit more clearance than on a 6?) I have taken the head off this engine once aleady to mend a snapped cambelt (and 10 bent valves!), so not too keen to rip it off again in a hurry.
- I wasn't intending to fit cam spraybars either, not sure they're really needed?
- with the medusa exhaust manifold (which really is work of art!), is there a heat-shield fitted to the top? My current manifold has one, not sure if the 6 does too.
- would I need a 6 ECU to do it justice, or will my existing maps just cope (i.e. add more fuel) given the more freely-flowing nature of the new manifolds?

I know I'm not going to make the same power as a 6, but I would expect another 15-20 bhp or so from these mods?

(Why not buy a 6, someone will say? Well, if you can find me a 5-door one, great - otherwise I'm sticking with the XSi. Plus I trust the car now, and have also sorted a load of bits on there - don't really want to throw that away and inherit a load of other problems!)

I appreciate most of these things are on here already, but I couldn't find any answers to these quite focussed questions of mine.

Any help would be much appreciated.

Lower CR doesn't necessarily mean you have more clearance. Surely easier to chuck in a GTi6 engine, loom and ecu. They are only

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Nothing to see here

The exhaust manifold is the first and best thing to do as the standard one is really restrictive- it is a knuckle scraping job but very worthwhile. The inlet and cams will make a much less pronounced change as the standard ecu limits the revs just as the 6 cams begin to produce their best. It will run fine but not give it's best.
People who know lots more than me say the 135 hp 2.0 head is a good design.
6 cams caused no clearance probs on my 1.8.
The 6 engine transplant would give more power but weighs quite a lot and the box restricts the lock.
Go for it the 306 is a fine handling car and with more power a quick one-you should see 20hp and a bit more with a map for your set up.

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New Forum same high quality intellectual debate!
Team Zimmer™

Use the 5 speed box then! If you advance your 6 cams then the max torque comes in lower and stronger, over coming the rev cut issue

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Nothing to see here

PS - not quite sure what you mean by this?

On the 1.8 I was able to bodge/move the coolant hoses just enough to prevent contact. For safety I wrapped the manifold-before fitting!! It is a very good move indeed for underbonnet heat and hose safety. I also used heat protecting sleeving for the coolant hoses a really good move too. (Nimbus for suppliers were fine).
Just and exhaust manifold and cat change is worth the effort. Cams and inlet less so but less difficult to do. IMO the cams produce their best a bit high in the rev range on the standard ecu so a 6 one would be necessary to get the extra that the cams would enable.

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New Forum same high quality intellectual debate!
Team Zimmer™

any one on her fitted there exhaust manifold on. iv got one but i need sum one to do it for me

Be very careful fitting RS cams into an R head. As pointed out at the start of the thread, the RS cam has more lift. The RS head also has double valve springs, whereas the R springs are single. With 0.395" of lift, the R springs are almost at spring bind. Certainly an engine builder would never fit them that tight. If the springs do bind, you will say goodbye to the cams and lifters.