Baseline recommendations

[Sinatra]

A quick jab does nothing, really. A larger squirt and the engine very nearly stalls, but recovers at the last second.

[Right hand drive]

[Right hand drive]

Maybe time to experiment with IFR sizes.

[GTO Geoff]

Reading from the start of this post, there seems to me things that are fundamentally wrong...& will need to be addressed id you ever want it run correctly.

- very low vacuum, only 5". Just seems too low for the cam specs, CR. What is the ICL. Any air leaks?

- linked with the 'only' 5" of vacuum, is that will actually idle OK at 750 rpm. Is the gauge accurate? Would have thought 5" of vac would likely need 1000+ rpm idle to stay running.

[Sinatra]

[Right hand drive]

You didn't say what the cam overlap is but in light of the last few post you just might have yourself an engine that is going to be grumpy idling under~900-1000rpm.

[Right hand drive]

In comparison I have an sbc 383, 245* @ .050" intake 252* @ .050" exh with 110* lobe sep, single plane and had maybe 10 different carbs on it over the past 6 months and with all of them it gets shaky and grumpy under about 850rpm idle. Your ci is smaller than mine and cam larger.

Edit: I just quickly skimmed over the thread again. Has initial timing been mentioned. Probably want 25*+ depending on a few factors.

[GTO Geoff]

Yes, agree with RHD [ Is that you Basic? ]. Will want at least 25* of timing at idle & maybe as much as 50* [ yes, 50*!! ].

Try this simple 5 min test: With the engine idling, loosen the dist & slowly turn it CCW [ advances timing on SBM ]. I will bet rpm will increase & idle will get smoother. Vac will also increase. Keep going CCW until you get maximum idle rpm. Then check what the timing is. Do not be surprised if it as above.

Reply with the results.

[Sinatra]

When I set the timing last year, I went by total which was 36° and all in by 2,600RPM. As I recall, that left the initial timing at 25°BTDC. I will double-check that, as well as see if adding more timing helps. I assume the idea here will be to eventually abandon mechanical/vacuum advance and lock down the distributor?

[Sinatra]

I neglected to answer the question regarding overlap: 106°