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Right, I managed to plug those holes in the manifold, restarted and sprayed some various fluids around them and the manifold and no change in engine tone, so air leaks must be gone. When I went to start the car this evening after repairing the air leaks, the timing seemed a bit off, this confirms that it must have been there before.  Ran it up to temp and re timed it 20250514_205556.mp4 Apologies for the shoddy camera work! Still a fair bit to go but some progress is better than none. The pointer did seem a little back and forth a bit, is this normal with the strobe?  I think it might need a few timing tweaks once I get it road tested again, but for the moment I'd like to get the mixture on the carbs as close as I can as they were of course from a starting positon. Then very small adjustments if I fiddle with the timing? Anyway, I ran it then let it sit for a few moments and restarted. I've still got a little bit of slack in the throttle  and not use to this new starter yet hence the slight misjudge of letting go of the key. I've never really been able to start an su car without pumping the throttle as I turn the key? Is this just my crap setups? 20250514_210810.mp4   The video above was after a slight idle tweak, just to see how it idles and it held steady. It is quite shakey in the car at this low idle, would that be the lumpyness of the cam or my shite engine building? Anyway it's prohably happier at around 900 idle. I still need to find that dreaded scraping noise. I had the car up a bit and peeked around on the property for any sign of somthing scraping on it but nothing. Next time I get a chance I'm going to run it with both rear wheels off the ground and am I right in saying that if in gear spinning there is no scraping, then I can rule out the clutch or the box? As if that was a culprit it would do it all the time when rolling. Jacob  

I have used the std mk1 2000 stuff, spring, damper, needle etc. I am picking up the 1360 carbs tomorrow on semi-permanent loan, so can try those piston weights. See what effect it has. I will also dig out another wideband setup, possibly from the spitfire (though I need that this weekend for a trip, Gill is jumping out of a perfectly good aeroplane. Utter madness) As before, there is no clear progression with these carbs. Heaviy piston-light spring-heavier spring goes alongside progressively weaker needles, but as said the 6J 2000 mk1 needle is not too diffrenet to the 7J 1600 one.  Anyway, I am on slightly restricted duties today and tomorrow as I have just had a steroid injection in my rather arthritic toe. Beginning to get painfully throbby now the local anaesthetic has worn off. Gill has read the "instructions" so no faffing around under cars etc.

Pity Alan OTU is no longer with us as he was good at this game….. I do agree with Colin’s suggestion - got to be worth a try as it wouldn’t take long. ISTR that there is/was a fella (Pete?) on the TSSC forum who’d done a fair bit with 1600 Vitesse fettling…..

Tuning Stromberg carbs. You must relish a challenge! Just a thought here but if you are running the Mk2 cam with a much higher than standard (for 1600) CR then the basic 1600 carb tune is going to be way off in pretty much every respect. With those mods I am guessing that you will be getting something like Mk1 2000 performance, or maybe a little more, from the 1600. Given that Triumph went for springs rather than just piston weight for the higher engine powers it is likely that there was a reason for this. On that basis I would have thought that rather than trying to adjust piston weights to try and match the piston lift to air demand (something of a rat hole I would aver) you would be better of with fitting a spring. And the 'light' spring from the Mk1 2000 would seem to be a reasonable starting point given the likely engine performance. You could also start with the Mk1 needles too. And by remarkable good fortune it would seem that you probably have a good stock of those.😁 Just a thought... I am with Nick on the AFR values you seem to be getting though.

I do like the XJC and very nicely proportioned car. Nice wheels those. And rmoving the vinyl from the roof is a major upgrade in my opinion. Although a non-trivial undertaking I would imagine. Definitely would benefit from being lowered a couple of inches in my opinion too.

My thoughts exactly, I had fuel pooling in the carbs and dry plugs. But perfect compression. Somthing didn't add up I'll seal it up priperly if I get time tonight and start again from there i guess! I remember a similar situation on my mini once, in traffic, the breather from the block to the carb decided to come off, i had to rev the tits off it to keep it going and not conk out

Thank you, yes it's definitely the culprit, I tightened the manifold bolts and carbs whilst trying yesterday. When I had the engine running, I was spraying easy start and wd40 around the manifold gasket and carb gaskets listening for change in tone, but nothing so they must be all good. Didn't think of that bolt! Yes, fibre washer either. This explains so much

I have uploaded this video link to save file space above   https://youtu.be/Vet3iuNH69g?si=MAG6pthsoAYnYEd_

I recon that's a good candidate for the frustrations.  An air leak of that size could make it run exceptionally lean at idle.  It not only provides more air, but reduces the vacuum the carbs see so they won't draw so much fuel.  Fingers crossed here that this is the source of the issue.

That would explain the dry plugs and consequent failure to proceed. Air leaks are very much a major issue with carburetted engines! I take it you have a copper washer on both sides of that aloy plate holding the return springs. With that lot found tomorrow should see a mjor improvement. Good luck