Fixed! Thanks guys!...Quick Fuel Secondary air adjustment

[AC Ventura]

Hi guys. Some time ago, I posted how my aluminium 427 FE powered AC Mk IV was a little disappointing to drive. The exhaust had a crackle at low speed, it was hard to pull off smoothly and worst of all bucked like an agitated mule on a trailing throttle. Plus the plugs were as black as soot. So thanks to everyone who posted in particular Dan EC, Gaz 64, Hauss, PeteF and Ret Cop. Basically, I finally got what you guys were on about. I removed the HR 780 and sure enough the primary transfer slots were exposed around .080”, clearly allowing too much fuel in on idle. That was the exhaust crackle, basically unburnt fuel igniting on the way out. Therefore, closed them down to .020”. That enabled the secondaries to be cracked open via the almost secret grub screw stop. However, this wasn’t easily accessible when installed on the RPM intake. Therefore swapped that out for an inverted bolt and found a spring to help keep that still. I also fitted a more open, 4 x Cherry Bomb under car exhaust.
Started the car, warmed it up and free rev, exhaust crackle gone! Took her down the road and I can now drive smoothly at low speeds and the bucking on the overrun is virtually eliminated. Plus it feels like I’m now getting the full fat 500hp experience.
I’m so grateful to this forum and can’t believe such tiny adjustments could make the car as good to drive and sound, as it is to look at! Thanks again.

[AC Ventura]

Car anything by grey now..!

[DanEC]

Glad you got the tuning worked out. Love black and white photos of these cars to give them a period look.

[AndrewB]

I would like to second the thanks to everyone in that thread as well. I was having a hell of a time getting my car to idle nicely while transitioning smoothly -- seems I could get either one or the other. Using the tips in the thread, I spent less than 30 minutes and the car was running incredibly. Thank you all again!