Skoda Rally Blog

OK, so after yesterday I thought it best to leave the engine to cool down completely before removing the head, as I didn’t want any problems.  And that was wise, as the dismantling was fairly straightforward, as you’d expect with something that was only assembled 5 days ago.  Everything came apart easily enough, and the head has been undamaged by its undignified start in life.  Phew!

The bottom end seems to be a different story.  It would appear that most of the problem comes from the rings – from what I’ve been reading since yesterday, a too-gentle break-in can be a problem, as can too much fuel.  Both of which definitely happened when these were first being run – it was taken VERY easily for the first few hundred miles, so that could be a problem, and it was also too rich.   There is lots of oil build-up on the tops of the pistons, as seen on the one on the right in this picture – the ones on the left have been cleaned, while no.3 is untouched (and black and sticky!).

Hello, again, pistons.

The bores seem to be a bit glazed, from what I can tell, so they need honing:

Glazed bores? You decide!

The plan with these is to remove them (taking the sump off, then pistons out the top), and then hone the bores.  They can be removed from the block to do this, which is probably the best idea, as there will be grit, and grit and engines don’t really get on too well.  Or at all.

The other problem is whether or not the head gasket was actually blown – there was no evidence at all of it having done so when looking at the gasket, and the liners seem to be the right protrusion above the block – they certainly seem to have been clamped down well by the head/gasket as the gasket looks (to me) to be spot on.  However, the gasket was a bit dodgy, it turns out, there were a couple of bits of surface rust on it, which I’d not spotted.  I looked at another one in the same packet, and it too has some rust marks on it, so I’m hoping this is the issue, although I will have to re-do the liners anyway if I remove them.  All the parts to do all this are arriving tomorrow, so hopefully by the end of the weekend it will all be done and the car will be running properly.  End of the weekend?  Why?  Well, today’s my birthday, and I’m “out out” tomorrow night, so I’m not sure how precise my work will be on Saturday – I’m hoping to get everything out tomorrow afternoon before the carnage begins.

2 weeks to RallyDay!

…it was going to be easy.  Today started out well enough, went to the Post Office, taxed the car, got it started easily, got everything set up for mapping/logging, and then went for a short drive.  Came back, and noticed that the engine seemed to be breathing quite heavily.  Not a good start, but it seemed happy enough, so I carried on, and did a longer drive with the LM-1 logging everything it needs to do the mapping changes.  Car went well – not outstanding, but well enough for a first run, and didn’t play up, even ticking over without problems.  When I got back it seemed OK aside from being a bit smoky again from the breather.

Took all the data from the LM-1 and put it into the computer to adjust the map settings, and I’d forgotten how to do a lot of it (as you have to convert the ECU’s format into a CSV file, and then import that into Excel, and use this in conjunction with the LM-1 “LogWorks” software to calculate new map values, and then transfer it all back again, and finally upload it to the ECU) – it took an hour to get all this done, but it was then time for the second run.  I fired the car up and it didn’t seem to great, seeming to miss on one cylinder, but I thought it would clear.

It didn’t.

Came back and did some checks – low compression on number 1 cylinder, the other 3 were OK.  Putting oil down the bores increased the compression by 2 bar, even on the bad cylinder, so my diagnosis is that the rings didn’t bed in properly on this engine, so a new set are needed along with the liners being honed.  And, of course, a new head gasket and I would think re-setting the position of liner number 1.  Not a total disaster, but certainly not what I’d like to be writing about today.  Parts have been ordered, but won’t be coming until at least Saturday morning, so that leaves me plenty of time to get it ready for RallyDay…

Today was all about making sure the car would be ready for tomorrow – as I can tax it tomorrow and drive it on the road, and therefore get some rough mapping started.  There were a few odds and ends to sort out on the car, none of them that important, but each one needing to be done in anticipation of tomorrow, including changing some bolts for the right ones (rather than temporary changes I’d made to get the car running), getting the brakes working OK, changing the wheels for gravel ones (in anticipation of RallyDay aside from anything else), and checking everything that has already been done, such as the new suspension (remembering that I’d forgotten to do one of the spring collars up).  And then, seeing if the car would still move itself – it hasn’t done that for a long time.  I decided to start out with the same map settings we used for Rally GB 08, rather than what I’d done afterwards, as much of the engine is the same, and I’d think it probably will be similar at low revs.  And this seemed to do the trick – the car drove perfectly up the drive, and on my, er… private test track of 100 yards or so.  So I gave the car a good clean for its good work.  Tomorrow will be much more demanding!

Nice and shiny in the sun.

Having had several enquiries, we have made more space on the front of the car for some £20 spaces (as all the current ones on the car had sold out), so we’re pleased to welcome Alex Lake and Will from Motorsportforums and Briskoda, who now have pride of place on the front of the car.  If anyone else wants another equivalent-sized space, please contact us and we’ll see what we can do!

After yesterday’s defeat, it was time to address the problem – I’d double-checked everything so I was sure the cam timing was right, the clearances all adjusted, everything else that could stop the engine wasn’t a problem, so the crank sensor must be the problem.  I got a timing light onto the car, and turned it over – and saw straight away what the laptop had said – the ignition timing was indeed all over the place.  The crank sensor was either faulty or just not in the right place – turned out that there was a but of rust on the end of the trigger, and it was also slightly in the wrong place, and the two meant that the ECU was getting a signal it just couldn’t deal with.  A couple of attempts saw it lined up perfectly, and suddenly a rock-solid ignition pulse showed on the front pulley with the timing light.

I reconnected the injectors, and….

… it still wouldn’t start!  It sounded more regular, but still didn’t want to go; it was willing but unable, basically.  I took the no.4 spark plug out to see what it looked like, and it had fuel on it, so that wasn’t the only issue.

But then as I was re-attaching the spark plug lead, I realised what had happened.  When I’d reconnected the leads, I’d swapped leads 3 & 4 over – on the old set of leads they were easy to spot, but now 3 & 4 are the same length, and I’d got them the wrong way round.  Hurried round, paused for a second (in a “I really hope this does the trick” way), and turned the key….

Instantly, it fired up!  Sounded good too.  Seemed lean, though, as it died quickly after (the ECU has a “priming” effect where it injects more fuel just as you turn it over to get it going), but that is good news – the new head and manifold should let more air in, so you would expect it to be lean at this point.  Fired it up again, and managed to keep it going this time – it sounded keen, and also mechanically good, so that’s a great start.  I can’t do any mapping until Wednesday as the car needs to be on the road for that, and it’s not taxed at the moment, so tomorrow will be spent checking everything over, and finishing off a few little bits here and there, but it is currently looking good.

Motor Excel - let's hope so!

Always good when a company puts their name on their product – but the proof of the pudding is in the eating.

So, with the trauma of total engine removal out of the way, it was time to get everything back in place.  Most of this is just straightforward stuff – obviously the driveshafts, gear linkage and cooling system, etc., are all unchanged, so are a piece of cake to put back on – particularly as they’ve been done so many times that everything is nice and easy – with the grease trick, even the driveshafts only elicited one expletive.

But of course there is the new manifold to put in place – and this is an unknown; it’s not just a manifold that you bolt on, there are all the bits that fit onto it – I was expecting to need to modify the fuel rail and so on, but I needn’t have worried; everything standard fits perfectly into place, which was a real relief!  Almost seemed too easy.  However, the one thing that was left which wouldn’t bolt on (and nor would I want it to) was the air inlet – the standard Skoda item is an odd shape and has always looked a bit restrictive (and indeed has made a dramatic difference to the way the car runs whenever it’s there, so I guess it must do).  In addition, the mini-kit manifold doesn’t have the mounting points for it, so it was bin time.  Fortunately I’d planned ahead and got the right sizes of silicone tubing and elbows to fit, and there’s just enough room to get it all in there – it looks like some kind of Max Power turbo jobbie now with blue silicone tubing and aluminium as well.

Ah... max power!

Time for fluids – oil, gearbox oil, water, and double-check everything.  I disconnected the coil pack and injectors and turned the engine over on the starter to let it build oil pressure which it did quickly enough (it’s got to fill the oil filter and all the galleries, so I’d rather do that at low speed with no load on anything).  And then…. time to see if it would fire, so I reconnected and turned the starter.

I wasn’t ready for what then happened – it didn’t fire up.  In fact, it sounded really bad – it was popping in the inlet, and sometimes slowing down suddenly, like the timing was off.  I got the laptop out, and connected it to the ECU, and tried again with the DTA diagnostics page on.  It showed the engine speed jumping around all over the place, which would make sense – the ignition timing was clearly not right because the sensor wasn’t working properly.   By now the battery was flat and I was feeling pretty deflated, so I left it – being a Sunday afternoon the shops were now all shut (Bank Holiday weekend), and it was best just to leave it rather than carry on – one thing I’ve learned is that desperation and tiredness don’t usually elicit a good outcome!

… is how today was supposed to be.  In essence, remove the old manifold and cylinder head, check the height of the pistons above the liners (which should be 0.6-0.7mm), and then put the new head on, put the manifold on, make all the right adjustments and then fire it up.  Easy.

So, I got started fairly early, and removed the old inlet manifold and the exhaust, and then it was time for the head to come off.  Basically, undo bolts, easy enough.  I’d drained the water out of the engine yesterday, so it was all nice and dry, and all went according to plan.  Once the bolts were undone, the pressure of the cam on the two open valves in the engine meant the head was already pulled away from the block, and nice and easy to lift off.  I took it off and put it in the garage.  And noticed something unusual – usually the head gasket stays with the block, but this time it was stuck to the head.  Fair enough.

Then I went back to the engine, and thought I must have been seeing things – the gasket wasn’t on the head, it was on the block.  Had another look at the head.  That had a gasket too.  There were two gaskets fitted to the engine.  Alarm bells sounded.  Those of you who are regular readers will know this engine was bought early in the year (when it was snowing), and installed with the help of a friend ready for the Sunseeker, and wasn’t run that much – just to check that it fired up – as it was time for mapping when I became incapacitated.  So this engine hadn’t done a lot of running.  And it had never really run right, it seemed a bit lumpy.  And I guess I was seeing why now.  I went back to look at the head, and noticed something else which wasn’t right – the edges of the inlet valves were shiny, which made it look like there had been valve/piston contact.

Valves should not have a shiny bit on them!

So I then took a look at the pistons to check them.  Same story there – shiny bits on them, where they had clearly been hitting the valves.

Pistons shouldn't have shiny bits either!

So, this wasn’t looking good at all.  Time for some measurements – the head builder told me that ideally there should be a 0.8mm clearance between piston and cylinder head, and a compressed gasket it 1.5mm.  So I’m looking for the pistons to be 0.6-0.7mm above the liners.  I got the verniers out, and measured…. 1.2mm.  Clearly not going to work either.  I then took a closer look at the pistons, and they seemed to be very loose in the bores.  Plus I had no idea what the problem was with the camshaft – it could be the timing was a long way out leading to the interference between the valves and pistons.  In short, looks like I got a complete pup.  And more to the point, time for a different bottom end – there was NO WAY I’d risk my new head (which cost over £1000) on this.  Fortunately, I have a couple spare!

From the shed, up came the engine that did Rally GB 2008 – this was a good engine which ran well but was limited by the head and inlet manifold, so I got the head off and measured the piston protrusion – spot on at 0.6mm.  Then did a dummy build with an old gasket (handily I have a few about) and the new head, to check valve to piston clearances with some plasticene on each piston, plus also getting the valves set up and checked.  Only takes a second to write the sentence, takes about an hour to do.  But all was good – had a 0.92mm clearance to the head, which isn’t exactly right (being 0.12mm wider than spec), but is good enough, I think.  Then did the real build with a new TEMAC gasket, torqued everything up, and then transferred all the studs into the new head (which again, quick to say, a while to do).  The engine was pretty much ready to go in, but of course next the other one had to come out.  I’ve obviously done this a fair few times, so it’s fairly straightforward, other than the fact that I have a sling that I use that is usually attached to the head… which was missing, so getting the engine out wasn’t that smooth.

Split the engine and box, and then fitted it to the new engine.  I did this with the engine on a stand (I made a few up for storage purposes), which made is SO much simpler than before – usually this is a really annoying process, but with the engine held firm and square, it was dead easy.  And as if by magic, Kevin appeared – up to this point, Mum had been helping with the two-man bits, so was glad to be relieved of duty.  With the engine now in place, and the sling set properly, getting the engine back in place was dead easy – everything lined up easily, and it bolted up without any drama.

At this point I needed to stop because I have  my bike up for sale (which is how I’m paying for the cylinder head or the entry to Rally GB, depending on which way you look at it), so I wanted to tidy up before he came over.  Thankfully that paid off, so I have the money for the entry!

Tomorrow, everything else will be put back on, and hopefully in a position to fire up – the silicon hoses for the air intake arrived this morning, so it seems everything is in place, albeit with a lot more work than expected.  Here’s hoping it pays off.

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.

I’m pleased to say that space W has now been taken, by Unlucky Racing – more details on them to follow soon.

I’m pleased to say we’ve attracted a few more sponsors – Peter Garforth (who is yet to decide his message), plus www.the-natural-therapist.co.uk, and A Henderson has taken slot C on the car.  We have had a number of enquiries about larger slots on the car as well, and hopefully over the next few days I will have a major announcement to make with a deal with a sponsor for the car for the event.  In the meantime, head on over to the Sponsorship page and see which part of the car you’d like your name or business on!