Barcelona 24 hour preparations
2011 has been a slow starting year for the Hofmann's Lotus Europa but there has been good reason for the lack of competitive outings. After a very successful run the Brands Hatch 1000K race last year we made the decision to focus on longer races with the car and the 24 hour race at the F1 circuit in Catalunya, near Barcelona, seemed the perfect place to start but that meant waiting until September to go racing.
The Europa has been both fast and reliable but after three years of competitive racing was well overdue a rebuild so we begun the rebuild and preparation for Barcelona in earnest a couple of weeks ago.
Such was the popularity of the first build blog I wrote whilst preparing the Europa for its first race I am going to do my best to document this rebuild including as much technical information as possible. There are plenty of changes to the car specification going on with a view to making the car as fast, flexible, robust, easy to drive and maintain as possible so there should be plenty of interesting dialogue.
Alongside this blog I'll be posting up on various forums on which I welcome constructive criticism and will value the input of engineers and enthusiasts alike so please do feel free to discuss this build openly.
Time is stretched during the build so I will try to be as succinct as possible and post lots of photos as taking a picture is a lot quicker than writing a paragraph.
So… I’ll start from the top; Engine and gearbox:
The engine that’s been in the car for three years was originally conceived as an interim engine spec. The idea was that I would start with a fairly standard engine utilising as many Vauxhall components as possible, which would run reasonable HP figures at minimal cost whilst I developed the chassis. In the event the engine has exceeded all expectations and run big HP numbers with amazing reliability so there has been little need to develop it much further with expensive additions like re-worked cylinder heads and steel crankshafts. The intention now is to perform a simple inspection and rebuild with a couple of minor changes to take advantage of lessons we have learnt on the race track.
Changes we are making include:
- Painting the engine block Red!
- Adding some extra ‘LEH’ oil squirters in the block if I can get the parts I need.
- Improving the chargecooling system to add redundancy and cope with the extra ambient temperature in Spain.
- Improve the oil cooling for the same reasons as above.
- Improve the heat shielding. Over the years we have strapped on bits of Nimbus and heat barrier where necessary but it doesn’t look pretty… now is time to tidy it all up.
- Improve some of the turbo pipework, utilising some ‘Wiggins’ type clips.
- Considering changing the wastegate to the new Tial MV-R water cooled design as the HKS one has been quite high maintenance and this Tial unit has proven very effective on the production Europa Big Turbo kit we have produced.
The gearbox has proven very strong and other than the addition of the Quaiffe ATB and a cooling system its remained untouched since the car was built. This should be a straightforward strip, inspect and rebuild with all new gearbox and diff bearings.
First time the engine has seen the light of day for three years!
Good view of the twin scavenge dry sump pump and oil air seperator.
Knocking the main caps out with 'special tool', ie a bent bolt and a slide hammer.
Engine all shiney and red.
Gearbox casings split and gear clusters removed for strip, inspection and overhaul.
This is a selector fork which should have a little plastic cap on it which bears against the selector. At some stage this has broken up which hasn't caused any detrimental effect on the change but has caused some further minor damage that has been repaired.
You can see the plastic cup on the other side of the selector cracking. This is clearly an inherant issue with the box and something that I will need to keep an eye on.
You can see the edges of the teeth on the selector have been slightly damaged from the misalighnment caused by the missing part of the selector fork. I have replaced this part, along with the selector forks.
Fully rebuilt gearbox with new bearings, new selector fork, new selector, new diff seals and release bearing and all checked and cleaned.
The car had its wheel bearings replaced after the accident at Brands (out of precaution) and has had two wishbone bearings but other than that has needed absolutely no attention so as a result of that is looking a little grubby. My plan is to strip, re-finish and replace all bearings and bushes so I have another long preiod of maintenance free running (I hope!)
Wishbones rose joints all removed. The bigger ones are 100% perfect and also very expensive so will be cleaned an put back in, the smaller ones will all be refreshed although they were showing no signs of play whilst on the car.
You can see that this bearing has seen some heat from the heavy track use. A good time to replace.
You can see how the outer bearings are retained using a tophat and circlip. This is a Nitron design, a very good one.
Bearing collets. We need to list where they all came from as some of them are different to create certain geometries to get the car working on track.
Clean uprights :-) These Nitron uprights really are a work of art and have been very effective on the car, improving both the suspension geometry and the brake cooling.
Brakes are on the agenda next.
VERY robust wheel bearings. After years of problems with S1 bearings these have been a very refreshing change.