Been a long time since I've really had anything worth updating this thread with. Life has been busy and almost all of my car time has been focused on trying ot get through the Fiat welding. The Daimler has been doing a good job of being 'a car', and I've been using for almost every journey I take that doesn't require child seats.
It is definitely due a polish ahead of the summer, and well a wash probably too! Still it's been a good work horse doing many runs to the supermarket, tip and to work on those few days I've needed to be in an office.
I've been working on the tuning a bit, as big mods have been put on hold. I fancy a bit more noise, and a little more performance wouldn't hurt, so some experiments with air filters and exhausts was the order of the day.
Step one was to see how it sounded with a less restrictive air filter setup. The standard set-up has the 1 1/2" carbs sucking through a tube that tapers down to 1"... that's gotta be a major restriction and noise killer. With no room to flip the air filter lids, my temporary test was to cut some circles of steel out to replace the lids.
Having my Wideband ARF gauge in the car in preparation for the fuel injection is making it much easier to know whats going on wit the changes I'm making.
There was an obvious increase in induction noise, which I approved of, and around town at light throttle and up to about 2300rpm it ran fine, but above that is went seriously lean. So as I thought, it looks like the air filter lid was a big restriction.
I know the Daimler SP250 ran the same engine but with a more open air filter set-up, which required a different needle in the carb, so that seemed a good place to start. I ordered a pair of the the SP250 needles, a 'TS' to replace the 'TZ' for my SU carbs, and popped them in.
And now things were much better, in fact now it was rich. The car had always been on the lean side (high 14s - low 15s AFR at almost all throttle positions and revs, apart from the idle which responded to the SU mixture adjustment easily) and required some very thick dashpot oil to get half decent tip in, but now it was actually too rich, especially at high rev (very light throttle was 12s, mid throttle in the 13s and large throttle in the 12s, tapering down to low 11s by the red line).
So I thought, I wonder what else is different on the SP250, and maybe the exhaust is not as restrictive? I did want some more noise anyway, so within a couple of days I had some straight through silencers that were 4" shorter than the standard ones, and some tubing and was ready to chop up my exhaust.
First impressions are I think it's idling quieter than standard, which is a shame. Sounds really good at wide throttle though. Nicer tone overall. Just lacking a bit of that around town rumble, so might need to try some different silencers. Just need to work out if I need some of a smaller diameter or shorter length, if I want keep the same sort of wide open volume but bump up the idle and light throttle noise a bit.
On the carb tuning front, this did clean up my light throttle nicely, but it's still a bit rich at wide throttle openings near the red line, so I think I will have to look into some alternative needles, but it's still running the best it ever has from a performance point of view.
I had been noticing a ticking or whistling sound to the exhaust for a while at higher revs and large throttle openings, and was kinda hoping that it was a loose baffle or something in the stock silencers, but alas changing them made no difference. I knew my H pipe was kinda a bodge job, so I thought I'd cut it out, partly to test if thats where the problem was and partly to see how a 'true dual' exhaust sounded. The answer is, it sounds kinda cool at some points but kinda rubbish at many others and I will be welding a new and improved H pipe back in ASAP
.. oh and it didn't fix the tick/whistle. So I think that has to be a manifold issue now, possibly a crack?... and yeah thats gonna be fun to get at! Might just live with it for a bit!
Speaking of 'living with it', I've racked up quite a list of small issues over the past few months and just lived with them, but yesterday it was time to actually start fixing some of them.
Most importantly, and possibly least excitingly, I needed a new track rod end. This (cheap pattern replacement) one has failed after just a couple of thousand miles, so I decided it was worth buying a more expensive one and lets hope it lasts longer.
With that on I could do a quick home alignment...
... which, as it was dark by the time I finished and it had been a long day (those are my excuses), I completely messed up and now the steering wheel sits off at a wonky angle. So I'll need to do that again, haha.
So my plan for this round of maintenance is;
• Sort the alignment
• Fit an H-pipe back in the exhaust
• Fix the heater flap thats stuck on hot (not an issue till recently!)
• Investigate the inconsistent brake servo (possibly something to do with vacuum reservoir?)
• Modify the gear selector linkage to allow me to get all gears cleanly (theres some mismatch in there possibly due the non-standard valve body and no matter how I adjust it I'm either missing park or hold 1st)
• Oil and filter change
So quite the little list. Let's see how I get on over the coming weeks!
.. oh and it didn't fix the tick/whistle. So I think that has to be a manifold issue now, possibly a crack?... and yeah thats gonna be fun to get at! Might just live with it for a bit! 
but over the past week I had started to fear that it might be something other than an exhaust issue, and wondered if I might have an exhaust valve that wasn't seating right? Or might have wiped a cam lobe off? (something not uncommon in these engines from what I read).
