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Six Cylinders Motoring Notes - Well that didn’t go well!


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37 minutes ago, RobT said:

I could be up for a visit.  I've got some parts for @Heidel_Kakao and am wondering if a pony express might be possible i.e. leave them at yours for a bit until he's able to collect.

Would also be good to meet up with you and other shiters too obvs.

If you could drop them at the FOD that would be great. I won't actually be able to attend this one as I am due to be at the Retro Rides Weekender at Goodwood (with Cedric :)from Friday till Monday but I would be able to swing by the FOD on Monday the 31st on the way home to pick up the bits.

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  • Six-cylinder changed the title to Six Cylinders Motoring Notes - FoD Spring Bank Holiday Opening anyone interested?
On 4/19/2021 at 12:24 AM, Talbot said:

The bad news:  It's got a bad misfire, which is causing a fairly nasty knocking sound.  It sounds *exactly* like pre-ignition, just while the engine is idling and being gently revved.  However, it's not regular, and it's not a heavy metallic noise. Initially it sounded like the hydraulic tappets needed to fill with oil.  It's not that.  Then we looked at firing order and any other ignition related issues.  None found.  Next was to see if it's cylinder-specific, and it IS.  Pulled the lead off cylinder 1, and sure enough it runs on 3 cylinders, but the intermittent knock is gone.  It revs up smoothly on 3, no issues.  Re-connect plug lead 1, and sure enough it's still running on about 3.2 cylinders, with various random knocks and bangs coming from it.  While the lead to Cyl 1 was disconnected, it was sparking against grounded bits nearby where it was hanging, so I don't think there's any issue at all with the ignition.  I also had all the plugs back out again, cleaned and gapped them and played mix-n-match with them, so I don't think the plugs are an issue.

Well, after looking somwhat further into this, the "misfire" has very much been found:

On 4/20/2021 at 11:37 AM, Talbot said:

Followers and stem caps fitted with a swipe of grease to hold them in place.

AHAHAHAHAHHAHAAAAA FAIL.

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It's not hugely clear from the photo, but what you can see there is the top of the Hydraulic adjuster (which is the "fixed" fulcrum point for the rocker arm) and the rocker arm that has come off the fulcrum and is now lying sideways, jammed down the side of the hydraulic adjuster and the valve spring.

The exhaust valve wasn't opening in the slightest.  That means the exhaust stroke of that cyliner wasn't actually exhausting, it was simply re-compressing the hot exhaust gasses, the inlet valve then opened and a blast of hot exhaust was shooting into the inlet.  That was then being drawn into other cylinders, meaning that when they ran their compression stroke, the mixture was already massively over-hot, so it was pre-igniting in a fairly massive way.  Hence the very nasty knocking, and the rather random nature of the knock.

By disconnecting the spark plug on Cyl 1, it was no longer firing red hot exhaust gas back into the inlet, meaning there wasn't pre-ignition happening randomly throughout the engine.

993312818_20210425_1149561.thumb.jpg.e50bb483ecc678688985b4abb36277bf.jpg

So, it's cam cover off, and get the rocker out.  Got the hydraulic adjuster out as well to check it for damage (thankfully none found) and luckily the only damage anywhere was a tiny dint in the very end of cylinder 1 exhaust valve lobe.  It's majoratively on the area of the lobe that has clearly never contacted the follower, so in terms of the engine it will make sod-all difference.

At this point, there's two options:

  1. Take the cam carrier back off again, which means removing the head bolts.  That then leads to the thought of do I just wallop the same bolts back in again without disturbing the head, re-compressing the gasket?  That also would mean completely stripping the timing end of the engine again... something I have zero appetite for.
  2. Use the tool mentioned by Andyrew previously and hope I can get the rocker/follower and hydraulic adjuster back in, on the cylinder with the least space to work in.

1 is off the table.  So it has to be 2.  Quick message to Andyrew, and by utter luck, the tool needed is instantly to hand (it could have just as easily been buried under 2 tonnes of "stuff"), so he brings it up.

an hour later, and after some rather fiddly and careful work, the adjuster and follower are back in.  The basis of the tool is that you end up compressing the valve spring *much* further than the cam would ever do so, meaning it's as far down away from the camshaft as possible.  The rocker follower goes in next, but pushed over to one side (and on it's side) to keep it out of the way while the hydraulic adjuster is dropped back in.  Then with varous bits of pokey wire, needle-nose pliers and a lot of fiddling (and a modicum of swearing) the rocker can be manipulatied back onto the fulcrum.  The tip of the rocker can then be carefully lifted up and the tip follower (which goes on the end of the valve stem) gently put back in.  After checking that everything is lined back up, the tool is removed *VERY* carefully, putting the spring load back on the follower and keeping everything together.  This has to be done absurdly carefully, as the rocker/follower and valve stem/tip follower will fall off at the slightest provocation, and I couldn't get any more grease in there to stick it all together.

Once that was done and the engine turned over twice to confirm it'll stay together, all the rest of the parts were put back on:  Cam cover back on, cooling fan, cooling fan cowl (which is about a foot long, but there you go) and a few other clips.

Run up to temperature, coolant flushed again, sacrificial oil dropped and some fresh put in.  Bonnet back on, and it drives.  It's still running on 2-year old fuel (so does splutter a bit) but it drives.  Thank goodness for that.

What was previously PARTIAL SUCCESS is now FULL SUCCESS.  W00t!!!!1111!!111one11!!!eleven!

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Worth noting that the car was running with about 1/3 of an exhust system at that point, so the slightly spluttery nature of the engine running on 2-year old petrol was significantly accentuated.

After driving it a few hundred meters, it did clear up somewhat.  Still needs MOAR exhaust pipeage.

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14 hours ago, Heidel_Kakao said:

If you could drop them at the FOD that would be great. I won't actually be able to attend this one as I am due to be at the Retro Rides Weekender at Goodwood (with Cedric :)from Friday till Monday but I would be able to swing by the FOD on Monday the 31st on the way home to pick up the bits.

Just to confirm, the Weekender is the 29th/30th May, not this weekend coming. ;)

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30 minutes ago, dollywobbler said:

Just to confirm, the Weekender is the 29th/30th May, not this weekend coming. ;)

We are talking about this weekend at the moment 1st, 2nd and 3rd May. I have not yet had any conformations but can do any or all days.

The end of May bank holiday will become a possibility when I have seen a weather forecast in a couple of weeks.  

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  • Six-cylinder changed the title to Six Cylinders Motoring Notes - FoD 1-3 May Bank Holiday Opening anyone interested?
6 hours ago, Mr Livered said:

I’d love to come and meet some shiters but it won’t be possible this time. It’s a long way from where I live in Devon, though annoyingly I need to be in East Claydon during the week after. Some things just don’t _quite_ work out..

That is only 6 miles from us if you would like to call in for a  cup of tea in the garden you would be most welcome.

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  • Six-cylinder changed the title to Six Cylinders Motoring Notes - FoD 1-3 May Saturday and Sunday weather looks good, anybody coming over?

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