At what RPM does your 350 SBC idle?

[Gregski]

Rather than staring WWW III asking more timing advance questions, let me just ask you this:

When your V8 350 cubic inch small block chevy is warmed up properly and purring like a kitten, what is your tachometer reading? What RPM is it happy at?

Since the manual splits the idle adjustments into Automatic and Manual, please let us now which one you got an auto or a stick, thank you very much.

[Gregski]

apologies I accidentally dropped this in the wrong forum, it was meant for the 73-87 section, but if you don't mind please provide your feedback as well

[BruthaMan]

350 crate motor at 260hp, idle set at approximately 650-700 rpm.

[Wrenchbender Ret]

Same engine as Thaman. Manual trans. 3-2 carbs. It idles real nice about 700 RPM.

[Racer382D]

Truck isn't together right now but the 350 in my camaro idles right here.

http://youtu.be/JMm3QcF9-R4

[48richard]

350/ TH350 idles at about 550 in park, and 400 in drive with A/C on.
As an aside, a couple of years ago I was very close to not passing emissions at idle, so I slowed down the idle to 450 in neutral for my recent test. It was OK but not as smooth as normal. Solved the emissions issue, though.

[msgross]

sounds like it should be in the Engine Section...


700 or so seems nice

[Husker]

700-750
Ron

[71K20chevy]

Mine is not consistent, I think the mech. advance in my distributor is sticky. Anyway most times it's 1000 but sometimes I can get it to drop to 750.

[No8Easy2]

350/ TH350 idles at about 550 with AC off

[yuccales]

350/350, 650 rpms, timing @ 10, smooth 17ins of vac. Running good.

[Blue/72]

My 1972 with 350/350 combo idles at about 800 in park and 700 in drive, my brothers 1967 idles at 700 in park and 600 in drive and my dads 1969 350/700r4 with quite a few upgrades idles low at 600 and in part at 500 or below with a lot of lump from the cam.

[Gregski]

thank you all I think I will split the difference of what the manual says and the feedback I have received 600 ~ 900 and set mine back to 750 where it was before I replaced the points distributor with the H.E.I.

[Tinkermc]

I set mine at 700

[Pipesmatt]

1972 C-20.. stock 350/350.. in park, idles at about 650 warmed up.. 550 in gear.. just got a new Quadrajet yesterday, same idle rpms in gear but sputters at 550 at a stop... 3100-3200 cruising rpm at 65mph...

[davepl]

Bone stock cam, 650 in Neutral, 550 in Drive.

[57larry]

800-900

[jdalexa84]

my truck idlesat 650 when warm and in park 350/ 200-4r.
just finished the swap on trans and loving the 2100 rpm at 70mph

[Gregski]

Originally Posted by jdalexa84

my truck idlesat 650 when warm and in park 350/ 200-4r.
just finished the swap on trans and loving the 2100 rpm at 70mph

cool, what trans did you have before and what did it RPM at 70 MPH?

[jdalexa84]

I had a 3 speed standard trans and I was above 3000 rpm at 70

[Gregski]

Originally Posted by Pipesmatt

1972 C-20.. stock 350/350.. in park, idles at about 650 warmed up.. 550 in gear.. just got a new Quadrajet yesterday, same idle rpms in gear but sputters at 550 at a stop... 3100-3200 cruising rpm at 65mph...

thanks for the pic - Awesome!

[67chevy_hotrod]

Holley 650 and a comp hyd. 268 no stall converter, just shy of 1000 in park and about 650-700 warmed up in gear.

[Mike_The_Grad]

Cold start: around 900 in park/750 in gear, after warmed up about 800 in park/and anywhere from 650-800 in gear.( seems to fluctuate for some reason.) 350 bored over.04,stock intake,comp cams XE250, H.E.I.,fresh rebuild original q-jet.

[geezer#99]

Originally Posted by Mike_The_Grad

Cold start: around 900 in park/750 in gear, after warmed up about 800 in park/and anywhere from 650-800 in gear.( seems to fluctuate for some reason.) 350 bored over.04,stock intake,comp cams XE250, H.E.I.,fresh rebuild original q-jet.

Likely caused by your mechanical timing starting to kick in.
What's your initial timing and where is your vac advance hooked to?

[Mike_The_Grad]

14° initial at idle, no vacuum advance currently. Found the diaphragm is ruptured.
When I pulled the dist. to adjust shaft endplay, I actuated the units control arm and about an ounce of varnished gasoline shot out of the nipple connection. The rupture formed soon thereafter.(I've rebuilt my 4MV since then,found a saturated float,and really fine beach sand clogged inside the entire pass. side idle feed passage and partially clogging same side main well pickup.) So I've capped the can off in the mean time,and plugged the timed port it was connected to. I get 20° mechanical. Determined by advanced light measuring at 3000 rpm with vac. Advance plugged, and with vac. advance connected. (Had 52° with it hooked up and initial at 12°,then disconnected had 32° total with initial at 12°)

To be honest geezer#99 I've been contemplating PM you for some advice on this, and maybe a second opinion on a theory I have that may be the root of the issue. But wasn't sure how to approach you. I spend a lot of time searching these forums for a solution to my issue,but don't really see the same scenario that others have had, and I see your name come up quite often with positive,valid info,and a logical approach.

Not trying to hijack this thread! I'd gladly take this elsewhere if only I knew how.