Car won't start

[anthony1956]

1 hour ago, Bob_Rich said:

Still pinning hope on the possibility that the carbs are too slack on the manifold   leading to air leaks

fixing that made a huge difference for me. edit: "not too slack" it's more subtle than that; it's some parts/sections are ok and others are not, so it's the difference in loose/tightness, otherwise the risk is doing them up too tight which is very tempting and easily done. The Cosworth rubber things are to protect the carbs from vibration and if done too tight that objective is lost.

My very old inlet manifolds were also allowing air ingress; so was all pretty much like trying to tune a sieve (which several of those in this thread showed me how to fix: for which thanks chaps  🙂   )

timing checked yet?

Edited 3 hours ago by anthony1956

[anthony1956]

incidentally, to check the inlet manifold to carbs interface gap, first I used a vernier caliper set to 2mm and would slide this around the interface looking for looseness or tightness and adjusting.

Then. I found the handle of a teaspoon I was using (in my tea!) was 2mm across and fitted perfectly in the gap in the Cosworth washers, much easier (faster) than getting a vernier in there - I still polished off with the vernier, but the teaspoon now lives in my toolbox 🙂

Edited 3 hours ago by anthony1956

[anthony1956]

assuming you have "misab plates" in there? So we are discussing both these: 

so that 2mm is that distance across the black between the two brass Cosworth "washers". I mention all of these details because none of it was clear to me when first explained.

Edited 3 hours ago by anthony1956

[Bob_Rich]

Hi Anthony

yes I am using new manifold mounts and Misab plates I got them for Burton Engineering  for a similar price 

The tightening up is from another  post based on the play when subjected to "Moderate force " on the air filters. As the air filters are not on yet  I have to judge how slack they should be. Several posts have suggested  2 or 3 mm  up/down movement  at the  air filter . I think mine are slack.  Even experienced guys like Roger King say it is all very "approximate." 

I will contact Paul ( Chelmsford  Weber man) on Monday for further comments  But my reasoning is increasing the amount of petrol does not make the engine run faster it need more Air and then that sucks in more fuel

Is this reasoning faulty??

thanks for continued interest in all my problems

Bob

[anthony1956]

yes more air, runs faster - likewise bad timing and of course both (what I had).  Yes approximate BUT one big caveat, equal gap all the way round both carb/manifold interfaces ; did you try the easy-start test? See if little squirts in different places.

2mm at the cosworth washers. all round. obessively.

2 or 3 mm at the filters (it does depend where at the filters) is much tighter than mine are, which are 10 or 12mm at the extreme outside - this is to manage the anti-vibration aspect, not the air ingress . Main thing is resist temptation to make them tight; exactly equal gaps is the thing.

I can probably find the instructions from the book if you are the donkey starving between various meals. Yes Roger was one of my guides.

TBH your litany of minor disasters sounds like timing - but hey.. we will see, eventually.

Edited 2 hours ago by anthony1956

[anthony1956]

28 minutes ago, Bob_Rich said:

thanks for continued interest in all my problems

no worries, I'm just returning the favours given to me on here. They'll shout loudly enough if I get it wrong! 🙂 (see below 😉  )

I think what I concluded was there is a list of things to check and ALL of them have to be checked every time, despite me saying I already did that. For example right at the end I found when I had refitted the HT leads for the umpteenth time I had two switched about on the dizzy cap. Embarrassing!

because it may not be one problem but several - my timing was way out (much further than yours might be) and I had not touched it.

Can't find it now but you mentioned the cams and two cylinders similar: you need to know which one is on the compression stroke.. various ways to do that  for No 1 ?

Edited 2 hours ago by anthony1956

[OldAndrewE]

If it is leaking air at the manifold or the carb mounting that will weaken the mixture, not make it rich. The effect of this will depend on how the mixture is set.  It is more air through the carbs that will draw more petrol

[anthony1956]

Timing gun alone: In the absence of someone to crank the engine, I duck taped the strobe gun in place pointed at the Tippexed timing marks, taped its trigger "on", taped a video camera in place looking at the timing marks, and went and cranked the engine myself.

I could have remotely viewed from my phone what the (GoPro) camera was seeing, but didn't think of that at the time.

Edited 1 hour ago by anthony1956

[anthony1956]

How do we know all the crud has been cleaned out?

methinks a check list of all the suggestions since the start o p.. to avoid going round in circles like I did.. for weeks, now months, but now it's my choice to explore. in fact I am beginning to think better have the carbs cleaned out by your Weber guy, to remove all doubt. 

It's been a fun Saturday evening 😉

Edited 15 minutes ago by anthony1956