Answer: We do two specifications of cylinder head. The first one uses standard valve size, wasted stem valves, bronze guides and is fully ported with combustion chambers matched (price approx. £1,000). The second head we do, normally only fitted to engines of 280bhp and above, is approx £2,500. We believe from the test results we have seen, the first head will produce approx. a 10 - 20bhp increase. This is dependant on the rest of the specification of the engine. We only recommend this kind of modification on carburettored engines over 220bhp and fuel injected ones over 235bhp. The second cylinder head would produce approx. 20 - 30 bhp more and again only worth using over 280bhp.

I would think there must be some other reason why your friend’s car produces so much bhp. Possible variables are ram pipe length, exhaust manifold design, even rolling roads vary dramatically from day to day and rolling road to rolling road. We have seen in excess of a 50bhp loss from the worst to the best exhaust manifold and system. So before you start spending money, I would suggest that you get your friends car to a rolling road at the same time as yours and do a back to back test. If you have a picture of the exhaust manifold and intake system fitted to your car, I may be able to give you a better idea of where your friend’s engine has been achieving more horsepower.

I don't recommend camshafts unless you have at least pocketed pistons. You would again, be simply throwing money away. If you look at the section on our web site called 'do's and don'ts' this should give you all the reasons why.

Answer: The weight varies quite a bit according flywheel modifications. For example, our engine with dry sump system fitted, lightweight flywheel, clutch & fuel injection is 90kg. Height again varies, but if I give you the height excluding the sump pan, it is approx 440mm high. The dry sump pan we do is a minimum of 65mm at its smallest (wet sump pan likely to be closer to 100mm deep).

Answer: There is a 20XE and a C20XE, effectively they are the same engine and the C denotes a catalyst. Any other number and letter combinations would represent a different model of engine.

Answer: The block dimensions as far as the head stud pattern, are identical on both blocks. The block as far as I am aware, is taller on the 2.2L engine because it has a longer stroke. I cannot be sure as to whether the rods are longer on the 2.2L engine. If they are this could present a problem, as having custom rods made to mount the XE pistons could be quite expensive, as a one off, possibly in the region of £200 each. If you are intending on using the engine as a turbo charged version, this is quite a sensible way of gaining torque, but due to the large stroke of the 2.2L engine, if you intend on running it normally aspirated and making other improvements, such as making the engine rev higher through cam changes, induction changes etc. it would not be a good idea to use the 2.2 bottom end as the stroke is so large, that the engine would try and shake it self to bits. If you are trying to gain capacity I would do it by increasing the bore size to 88mm rather than trying to achieve it in stroke. 88mm bore will give you approx. 2.1 litres. This is also a cheaper way of carrying out an increase in capacity, since the modification you are originally considering may have other unforeseen problems, such as the exhaust manifold may not fit under the sump due to its extra height, cam belts may be too short etc.

Answer: Yes they are interchangeable, the only problems you will have though is if you intend on mounting the coil pack in the original place the head will have to be modified. Two lugs will have to be fitted to the casting to support the coil-mounting bracket. You will also need to either fit the exhaust cam shaft from the Distributorless head, this has the correct drilling to except the wiper which is required to trigger the phase sensor. Or you will have to modify the end of the distributor type cam shaft to except the phase sensor wiper.