Another day, another trial

November 16th 2016

Firbank

Since I modified the fuel system and poked holes in the bonnet we did a trial at Firbank, which is a steep, wooded site near to Sedbergh, in the Dales.

Great day out. lovely weather and some real gains in performance. The overheating seems to be nicely under control. However there were issues with low oil pressure again. It seemed to be when the car was left facing downhill without the the engine running.

On re-starting the oil pressure was very slow to pick up, but then would get to the required 40 or 50 psi at about 2-3000 rpm.

I decided to ignore it as there were no awful noises. 

Several things seemed plausible. A crack in the pick-up pipe was my favourite and perhaps the wrong oil filter (the one I had seemed to be for a Mk3 Escort). Possibly the same as the Talbot Sunbeam one, but there are so many options available it's difficult to know.

We did get a puncture. This is the second one in two outings. I was beginning to think that tubed tyres with bolt-locked beads is not so good. Never had a flat with tubeless tyres.

We were still running the T-Trac tyres which are no longer approved, but it didn't matter to us as I am not in the Championship this year, having started late.

Dockray

Getting home I decided not to do anything but wash the car. 

The next event we were going to was the next weekend at Dockray above Ullswater. A venue I have photographed twice, but not driven. 

Apart from being close to home, (15 miles) it is beautiful and as the farm is for sale, probably the last opportunity to drive it.

We seemed to be doing a lot better this week and I think we actually cleared some Hills

I even managed a smile for Glenn

Despite quite a lot of pointing going on we still went the wrong way 3 or 4 times. One was entirely my fault. One was entirely John's fault. The others were a bit of shared confusion.

Still. We weren't there to win. (fat chance)

Which is a good job as "someone" protested our tyres. Can't quite see the point other than being awkward. We are quite entitled to use the tyres, but just don't score points.

Some people take things very seriously.

The oil pressure -
- fluctuations problem seemed to be no better, despite having tried the proper oil filter for the donor car (Talbot Sunbeam).

When I got home I decided to whip the sump off and see what was the issue. It didn't appear to be the pickup-pipe which was in fine condition. Someone had suggested poor baffling with oil draining away from the pickup, but as it had been like this for many years I couldn't see that suddenly becoming an issue.

So I took the top off the oil pump to check the rotor clearances. They seemed a bit large at 0.008" when the max should have been 0.006". The pump body ends were a bit scored as well. 

I took a big end and a main cap off. The big end was lightly scored, but not bad. The mains were perfect. 

I bought a new oil pump from long-time Imp specialist Reg Patten. Well, it was the gubbins for the inside of the pump. It's a high capacity pump so the rotor is deeper and needs an extension pump body section.

I had to remove the old pins from the drive shaft and fit it to the new rotor. 

This may help with the low revs oil flow, as that may be the reason I have been losing pressure.

When trickling at 800 revs or so there may not be enough suction in the old, worn, pump to pull the oil up the longer pickup pipe.

I had to slightly bend the pickup pipe so the strainer didn't foul the sump bottom. The pipe comes out of the pump body end cap which is now a bit closer to the bottom of the sump due to the extension part.

I also got a replacement pressure relief valve as Reg reckons the 80 psi start-up pressure is too high and may be caused by a stuck relief valve.

Who knows? It's all supposition.

Anyway, started it up and it ran properly.

I was entered for the Richmond event but my back was a bit iffy (too much time in the office) and I thought I would not be able to get in and out of the car easily, never mind walk the Hills in between.

So it's a month until the next event at Croglin up near Carlisle.

We'll see if the work has improved things.

Oh.

I did buy some Maxxis tyres to make me "legal". The T-Tracs were knackered anyway so it was time.

I took the opportunity to get some Ford space-saver rims from Bryan Walker and cut the centres out of two of them to make some spoked wheels. So the Maxxis are now running tubeless. Hopefully that will avoid puncture problems too much.

Have you looked at http://www.sportingtrialsforum.co.uk/ ?

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