Skoda Rally Blog

At last, the biggest parts of the solution to the lack of speed have arrived.  A new cylinder head and inlet manifold, which will hopefully transform the performance of the car.  Up until now, the engine’s performance has been limited by the parts available to me, and the biggest restriction has been the inlet manifold, which turned an originally quite quick engine into a somewhat muted one – it just couldn’t flow enough air, meaning that in the upper rev range the engine made less power than it should do, and instead of having a satisfying power band, it just petered out like a damp firework.

Today’s arrivals should change all this – a brand new cylinder head which has been fitted with larger valves (which are legal due to a homologation extension that Skoda filed in 1999), which would already make a big difference, but allied to the extensive porting work that has been done and combustion chamber modifications should lead to an engine which is much more powerful.  This has all been done by Motor Excel in the Czech republic, who have a good reputation (having built 1.4 mini-kit engines which produce over 150bhp!), and who have been excellent throughout the entire process – the only two british head builders who responded to me seemed to be less than keen, and would have charged me nearly as much for ‘development time’ as I was charged for a complete, brand new head, and one which looks to have been modified with great skill.

Shiny new head, ready to fit.

The head will really shine when fitted with the other part, the ‘mini-kit’ inlet manifold.  This is a much better design than the standard MPi item that the car has been running since being built (and indeed the previous Felicia did as well), which has much larger port runners, and a less convoluted design – notice how the ports runs are much straighter than the curvy ones on the MPi one.  You can see the difference between the two manifolds when they are side-by-side – the new one is on the right, and looks like the steroid-consuming brother of the positively wimpy MPi unit.

Wimp next to Gigantor!

It’s also in two pieces which allows hand-finishing to perfect it; the original MPi unit design made this impossible, plus the runners increase in diameter as they get towards the ‘plenum’ area (unlike the original, which was at best parallel; I cut one apart once to see what was what inside, and it didn’t make for good viewing!).

Underneath the manifold, all lovely and shiny.

There are still other parts to get hold of – I have ordered the right throttle body for the setup, and then I need to arrange the air intake to suit this setup (which hopefully will be off-the shelf silicone hose elbows and connectors) but this will be a big improvement in the car.  And you’d hope so, given that these two items alone cost me about a month’s wages (no, really), and to put that in perspective it is also about 50% of the original build cost of R477 KRU.  This, the new suspension and new diff will have about doubled the cost of the car since the last time it was driven in Rally GB, but should mean it is an altogether different proposition on the stages.