ClioSport Club Member
Saw your car at Marks yesterday Rob. Good luck getting it sorted. Fingers crossed for you and wishing you a good outcome!
I'm running Supertech springs as well but not the double ones. I sent them down to Nick at PMS to measure and supply me with the correct shims for them.The supertechs are still only a friction welded valve. It’s just higher up where they make the join when compared to the original Renault valves, so this could be a reason why they’ve failed.
What valve springs are you running? If the seat pressures are too high, that won’t help.
Believe me I have! It's a bit of a head scratcher. The only thing I can think of is that the lifter stuck momentarily. Either that or it was a rogue valve that fatigued over time.first time i've heard of one fail. i'd be looking for something that caused them to go, as mark said.
Please tell me the cam journals have been measured in terms of clearance after the hone?The last few weeks has been a combination of saving funds for the rebuild and the waiting for pistons to arrive from the states.
Last week I was away with the family on holiday but before I left the pistons arrived and I had time to brief Thurston Engineering before I left.
The new pistons are made by JE and come highly recommended by Nick at Pure Motorsport.
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As one of the rods had also twisted by a thou during the failure I managed to source 2 being sold used on Ebay which I got for £50. Worth a punt as a complete new set is £500! Fortunately one was good!
While I was away I received regular updates from Thurston, mainly to tell me to order something or give me news about more work that was required on the engine!
It seems the centre main bearing was a little loose so the block needed to be worked to sort that out and then line bored again. Having been done twice now this block really is at the end of its life so I need to start looking around for a donor engine to prepare.
As is always the way, with my next race at Brands Hatch next Sunday (25th August) and having just got back from holiday things are going to be tight!
The bottom end should be ready for me to collect Monday afternoon as the balancer couldn't do anything until the weekend and the dyno is booked for Thursday afternoon. Up until this morning I still had a new head to prepare as well before the engine can be assembled, so that is what I have been working on today.
Fortunately I run a fairly standard head with no porting or gas-flowing. The only thing I did on the last head was polish the combustion chamber. As this seemed to work for me last time I have done the same again. Who knows whether it really benefits from it?
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As well as this work, all the mating surfaces got cleaned and dressed, cam journals honed and head and cam cover painted. Tomorrow / Monday I will lap the valves in and assemble everything hopefully ready for when the block is finished.
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A mate who races in the same series has offered to give me a hand for a couple of evenings to get the engine in the car so barring any hitches I think we could make it. No time for any testing though and my new co-driver will be going in to qualifying having never driven the car so if we do get to the race on Sunday I don't expect we'll be in the running for any silverware. But I'll be just glad to get back out on track!
Rebuild looks impressive
Can I ask, how have you routed the feed and return pipes from the in tank pump to the wheel well? I can’t see a route
There is space for the hoses to run above the tank and between the body and then into the spare wheel well through two drilled holes.
I’m sure there’s a photo further back in my thread.
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At this point I either need to make excuses or eat humble pie, because by the end of the session he had settled into a nice rhythm and beaten my time by 3 tenths putting us in P6 and 1st in class for the start!
The night practice session was about the only time that the car ran (almost) at 100%. It was still misfiring a little bit. Still haven't got to the bottom of the problem, but then I haven't had much time to get into it since then.I was at the Donington meeting, watched most of the day from the Hollywood grandstand. Interesting reading about the issues, the car looked to be flying, especially in the night practice.