What do you guys think?
https://drive.google.com/open?id=1-PSzEaVoU5w1BE4cZ9XlfgMwSdLM2r94
and idle sound
https://drive.google.com/open?id=1-S6BgFMEdqU4e4vnFW7GS8cN_V6isODE
355 chevy block with dished pistons
305 416 heads, Valve lash at 0+0 to try and find sticking valve
New HEI, NGK Plugs, Wires
New Holley 650 Vac secondary, idle screw 1 1/4 out
Cam spec 224/224 at .05", 114 lobe separation
Cams are hard on vacuum.
That looks perfectly fine, certainly considering the cam specs, and hearing the idle. Worry not.
My daily driver is 231°/231°@0.050", 108°LSA and idles at 8" in drive at 650rpm with full manifold vacuum advance. And 10mpg driving it nice. Also a 350 with 305 heads, flat tops, and steel shim head gaskets.
That seems reasonable. It sounds like the idle could come down a little which would give you more vacuum at the expense of idle stability.
Yup. Looks actually better than expected with that much cam. What's your initial timing?
Looks good to me as well. Considering my last SBC (which Gimp has now) had 5.5" of vacuum at 1300 rpm idle, yours is doing good. My cam was just slightly bigger, wink, wink.
Thanks guys. I have been paranoid that I have a valve sticking. Because of an intermintent pop in the exhaust at idle
That pop could be a lot of things. Valve overlap reduces vacuum, and also makes it "jumpy." That gauge looked great, and the idle sounds lovely.
Often an idle exhaust pop with a lumpy cam is just because there is more unburned HC going out the exhaust and it ignites from time to time when the mix is just right.
Some people call that wasteful. I call it car porn. Nice tuning. Sounds great.
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