Not quite the Cadwell Park update I was hoping for...
Arrived at the circuit from the hotel nice and early, perfect conditions were on the cards for the day with MSV.
Was hoping for a really positive day with a few changes I wanted to test, ECU tweaks, Michelin slicks and the firmer rear springs.
Sighting laps went without a problem and the circuit was live pretty swiftly with it being low numbers, not sold out despite it being the holidays.
Session 1 - Went out and got some heat into the tyres and started to get use to how they felt, instantly confidence inspiring, car felt good and I turned on the autoblip on the downshifts, something I wanted to experiment with as the ECU has the capability and I am already to heel and toe but it would be nice to focus purely on brake pressure and braking towards the limit of grip to improve the stopping distances in the car.
Session 2 - Upped the auto blip duration to 0.8 second up from 0.4second and it felt pretty much perfect, have to remember to bring the clutch up to the top of the pedal stroke when doing multiple down changes but it was pretty much seamless only needing a few more adjustments.
Session 3 - I had noticed the car seemed a bit bouncy so I checked the damper settings, must have miss set them as the rears were turned up close to max, for reference I normally run the Gaz about 14-12 clicks from full out of 22 and that's a pretty happy spot I've found over the years, bearing in mind I'd gone to a slightly stiffer rear spring, (back to the standard spring the coilovers came with) I set the dampes to 10 clicks from full, slightly more rebound to control the stiffer spring was the thought.
Session 4 - Starting to get into the groove of it and had a good session following a couple of Caterhams, car felt better in person than it looks in the video, my observations were that the car is way bouncier than it was earlier in the year and since changing the rear springs it's lifting the inside wheel a lot on mid corners resulting in some slip of the inside tyre on corner exit which the Quaife diff cannot deal with, shame it's not got a plated diff.
Comparing back to Febs videos from Cadwell this is much worst and likely down to the stiffer springs as that's the most dramatic variable that's changed, possibly causing the front right corner to dip and unweight the rear inside wheel?
For next time it goes out I'll be going back to the set up earlier in the year with the softer springs and try a session without a rear ARB and see how that performs.
Well session 4 was brought to an abrupt stop...
On the pit straight changing from 3rd to 4th 7080rpm the oil pump shaft has snapped. I've continued to run the engine for 25 seconds before noticing the oil pressure was zero and turning off the engine.
So many people have asked already about the set up:
OEM oil pump and shaft this time with two pieces of lock wire, I do have an oil pump tensioner fitted to the block. I ended up as this point due to the following failures
VAC bolt came loose
VAC bolt lock wired, hardened shaft chewed the softer gear
oil pump housing bolts vibrated loose causing lower oil pressure max 40psi.
Turned the engine off as soon as I noticed and rolled down the straight towards the marshalls point on the right hand side, not wanting to pull down the steep slope at the marshalls point at the bottom of the dip, its pretty steep, I've been there before and no powersteering, I also didn't want to get stopped in the bottom of the dip, decided to roll it up onto the straight where the car was clearly visible and roll it off the circuit onto the grass.
Stripped the front end and got the sump off on Sunday.
As we pretty much thought, snapped the shaft clean, spot were the gear has shot off to, upwards into the tensioner and the crank
Lockwire did it's job, the nut didn't come loose this time!
Next job was to check some bearings. Despite only running for 25 seconds without oil pressure, the damage happens pretty quickly.
After seeing those bearings, the job changed to removing the engine so I can strip it, clean everything properly and rebuild the bottom end
As it currently stands:
I've organised for a different aftermarket oil pump set up to be fitted, will document this a bit more when it's finished and back with me.
I've ordered bearings, seals and gaskets to rebuild the bottom end when I have all the right bits
I will be fitted a harmonic damper to the engine after this final failure. We'll see what the future holds with one of those
While the engine is out, might as well use the time do a few more jobs, so i'll start working on that over the next few weeks while waiting for engine parts.