do these trucks when you start them normally have a loping idle? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

yellow400ex05 · 09-30-2012, 08:59 PM

I'm trying to figure out if my truck has an aftermarket cam in it and when i start it anytime after I start it whether is cold or hot it has a nice little lope to it, a noticeable one, I didn't put this engine together but apparently its a GM crate engine, so i think it might be cammed, but i can't be for sure. when its running and i put the clutch in after I've been driving it'll idle higher and wont have nearly as much lope to it, as if it just idles higher when you've been driving it.

anybody got a video of what these trucks normally idle like when started up? do they lope because they are carbureted?

Dieselholic92 · 09-30-2012, 09:21 PM

Bone stock small block Chevys have a relatively smooth idle.

yellow400ex05 · 09-30-2012, 10:34 PM

alright because when i start my truck it definitely idles a bit rough

74 stepside · 09-30-2012, 10:47 PM

If it has a lopey idle then it probably has an aftermarket cam. Make sure your timing is correct too. If you want video, just go to you tube and type in 350 with cam. Theres 100s to choose. See if you can compare.

motornut · 10-01-2012, 08:45 PM

yup started cold can sound kinda lopey till it's flowing
but if cammed the sound won't go away
but check timing,vac advance

yellow400ex05 · 10-01-2012, 08:51 PM

here's an idling video, it doesn't sound too lopey but it chops and it doesnt normally go away ever, this video the truck was hot.

how do i embed a video from photobucket?
http://s296.photobucket.com/albums/m...Picture316.mp4

*C-10 simplex* · 10-01-2012, 09:06 PM

What type of carb you got?

yellow400ex05 · 10-01-2012, 09:13 PM

quadrajet its not the factory 350 either, its either a 350 from 1969-79 by the casting number i read, but i cant read the casting code on the front head, due to residue from grime.

mongoose · 10-01-2012, 09:17 PM

maybe an rv cam at most?

what is it idling at? just sounds like true duals with crappy mufflers.. no offense.

yellow400ex05 · 10-01-2012, 09:27 PM

Quote:

Originally Posted by mongoose

maybe an rv cam at most?

what is it idling at? just sounds like true duals with crappy mufflers.. no offense.

i have no idea and yeah its just running some pipe off the header i'm getting dynomax mufflers welded in.

even when the chambered mufflers were in you could clearly hear a defined lope in the idle.

motornut · 10-01-2012, 11:36 PM

yup sounds lopey....tv speakers suck lol

meter swinger · 10-02-2012, 12:25 AM

Dosen't sound like stock cam or exhaust.
Posted via Mobile Device

tucsonjwt · 10-02-2012, 08:32 AM

I have a stock 83 C20 camper special and it has a rough idle for about 5 minutes after cold start, then it smooths out nicely. I have a manual choke, which I use sparingly. If I were to adjust the throttle screw it would not idle rough at all, but I prefer to save the gas.

09-30-2012, 08:59 PM	#1
yellow400ex05 Registered User Join Date: Aug 2011 Location: confusion, USA Posts: 206	do these trucks when you start them normally have a loping idle? I'm trying to figure out if my truck has an aftermarket cam in it and when i start it anytime after I start it whether is cold or hot it has a nice little lope to it, a noticeable one, I didn't put this engine together but apparently its a GM crate engine, so i think it might be cammed, but i can't be for sure. when its running and i put the clutch in after I've been driving it'll idle higher and wont have nearly as much lope to it, as if it just idles higher when you've been driving it. anybody got a video of what these trucks normally idle like when started up? do they lope because they are carbureted?

09-30-2012, 09:21 PM	#2
Dieselholic92 Registered User Join Date: Feb 2012 Location: Lynd, Minnesota Posts: 201	Re: do these trucks when you start them normally have a loping idle? Bone stock small block Chevys have a relatively smooth idle. __________________ Semi professional heavy equipment operator Amateur mechanic

09-30-2012, 10:34 PM	#3
yellow400ex05 Registered User Join Date: Aug 2011 Location: confusion, USA Posts: 206	Re: do these trucks when you start them normally have a loping idle? alright because when i start my truck it definitely idles a bit rough

09-30-2012, 10:47 PM	#4
74 stepside Registered User Join Date: Oct 2009 Location: SoCal Posts: 815	Re: do these trucks when you start them normally have a loping idle? If it has a lopey idle then it probably has an aftermarket cam. Make sure your timing is correct too. If you want video, just go to you tube and type in 350 with cam. Theres 100s to choose. See if you can compare.

10-01-2012, 08:45 PM	#5
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: do these trucks when you start them normally have a loping idle? yup started cold can sound kinda lopey till it's flowing but if cammed the sound won't go away but check timing,vac advance __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350

10-01-2012, 08:51 PM	#6
yellow400ex05 Registered User Join Date: Aug 2011 Location: confusion, USA Posts: 206	Re: do these trucks when you start them normally have a loping idle? here's an idling video, it doesn't sound too lopey but it chops and it doesnt normally go away ever, this video the truck was hot. how do i embed a video from photobucket? http://s296.photobucket.com/albums/m...Picture316.mp4 Last edited by yellow400ex05; 10-01-2012 at 08:59 PM.

10-01-2012, 09:06 PM	#7
C-10 simplex Account Suspended Join Date: Dec 2008 Location: indisclosed Posts: 1,515	Re: do these trucks when you start them normally have a loping idle? What type of carb you got?

10-01-2012, 09:13 PM	#8
yellow400ex05 Registered User Join Date: Aug 2011 Location: confusion, USA Posts: 206	Re: do these trucks when you start them normally have a loping idle? quadrajet its not the factory 350 either, its either a 350 from 1969-79 by the casting number i read, but i cant read the casting code on the front head, due to residue from grime.

10-01-2012, 09:17 PM	#9
mongoose Registered User Join Date: Feb 2009 Location: slurrey, bc. Posts: 1,134	Re: do these trucks when you start them normally have a loping idle? maybe an rv cam at most? what is it idling at? just sounds like true duals with crappy mufflers.. no offense. __________________ -'73 c/10 - Low with Go - will be complete... probably never. -'90 2wd Blazer - well... soon enough anyways. -'84 SWB - the daily gas guzzler.

10-01-2012, 11:36 PM	#11
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: do these trucks when you start them normally have a loping idle? yup sounds lopey....tv speakers suck lol __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350

10-02-2012, 12:25 AM	#12
meter swinger Registered User Join Date: Apr 2009 Location: Kennewick WA. Posts: 1,437	Re: do these trucks when you start them normally have a loping idle? Dosen't sound like stock cam or exhaust. Posted via Mobile Device

10-02-2012, 08:32 AM	#13
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,191	Re: do these trucks when you start them normally have a loping idle? I have a stock 83 C20 camper special and it has a rough idle for about 5 minutes after cold start, then it smooths out nicely. I have a manual choke, which I use sparingly. If I were to adjust the throttle screw it would not idle rough at all, but I prefer to save the gas.



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