I tell you what, idle that engine down to 550 and yur gonna see that estimated 9 inches plummet. Idle it up to 1200 and watch the numbers climb.
That is why others and I suggested a starting point of 850 rpm. Altitude plays it's role as does idle-timing.
When you hear a small cam idling like a top-fuel wannabe, you know that cam is either a poser or a guy tuned it to do that.
I remember when I had the 292/292/108 cam in my 367 at 11.3. After the cam break-in it idled all rumpidy-rump-like, too. But after a few hours it calmed right down. I could tell it was a big cam for a streeter, and if I had wanted what it had to offer, I would have kept it. But I owned the mistake almost right away, sold it, and pulled it, hyup in that order.lol .
I measured that cam as about
[email protected]. I think I found it advertised a few years later, at
[email protected]
I replaced it with a
[email protected], and reset the Scr to 10.7, and that made a real nice streeter. I'd still be running it today, if somebody would have told me they were gonna take the ZDDP outta the oil.Hyup, she dropped 3 lobes right after an oil change. That lil learning business cost me a G-note CAN$.
IIRC that 292DC idled at 9ish for vacuum.
So did the
[email protected] Hughes ....... but about 300rpm lower, and 8* less idle-timing,lol. I really liked that 223.
IDK what it would take for a streeter to idle at 5inches @ a typical 750rpm, and I'm never gonna build one either.
But I have sure tuned a lotta lotta motorcycles that idled down there, at 1000rpm even.
