Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
08-27-2016, 06:25 PM | #1 |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Sbc Falling on its face..
Well I just did a cam swap, broke it in per lunati' direction, changed the oil and put some street miles on it 70 to be exact... Then took a friend for a ride and when I stood on it it popped and coughed and fell on its face for like a second or two then pulled like normal.. Timing is 12 initial and 30@3000. I'm thinking the float levels might be a tad low but I didn't have that problem with the old cam! Any ideas?
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
08-27-2016, 07:09 PM | #2 |
Senior Member
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
|
Re: Sbc Falling on its face..
More timing first of all. You should be at 36-38 total with vacuum advance unhooked and plugged. What kind of carb are you using? you likely need to increase the accelerator pump volume. If its an Edelbroke you can move the accelerator pump rod. If its a holley you can go about it a few different ways. You can change the change the nozzle, change the accelerator pump cam to slow or speed up the pump shot.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member. |
08-27-2016, 07:22 PM | #3 |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Re: Sbc Falling on its face..
Speed demon 650. I'll try and give it more timing but do t want it to start hard. I'll try that tomorrow...
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
08-27-2016, 08:34 PM | #4 |
Senior Member
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
|
Re: Sbc Falling on its face..
With that carb... All I can say is good luck. Most of the best carb guys around don't want anything to do with a demon. I know the previous models were plagued with crazy issues that nobody could figure out without using a magic wand.
If you don't advance the timing more you will be losing so much power its ridiculous. 6 or 8 degrees of timing could be 50 horsepower or more depending on the engine itself. If you have a starting issue you need to address that separately. Make sure your battery cables are of proper thickness and cables clean. Make sure the battery is healthy. Make sure the starter itself is strong enough.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member. |
08-27-2016, 08:40 PM | #5 |
Registered Truck Offender
Join Date: May 2008
Location: hells training ground (aka Ariz)
Posts: 3,118
|
Re: Sbc Falling on its face..
I'd say 3part issue...
Get the float levels up where they should be, (cableguy and I are of like mond on the Demon carb... not a fan!) check the accelerator pumps for initiation as soon as the throttle is moved and if you need to up the squirter size,, do it. and get the timing corrected. Agreed even the most efficient chambers will like 10-12° advance static and 33-35°+ total,, all in by 3500-4000. Todays ethanol 'enhanced' fuels tend to like more advance than previous true 'gas' (0 ethanol) fuels. About 95% of all pump gas sold in the US is is 10% ethanol now that MTBE has been banned.
__________________
Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral. |
08-27-2016, 08:55 PM | #6 | |
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,403
|
Re: Sbc Falling on its face..
Quote:
__________________
69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
|
08-27-2016, 10:22 PM | #7 |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Re: Sbc Falling on its face..
Gonna mess with it tomorrow afternoon! Float levels, timing and check pump arm... I just don't understand why I didn't have this problem until after I changed the camshaft
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
08-28-2016, 05:04 AM | #8 |
Senior Member
Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
|
Re: Sbc Falling on its face..
What Lunati cam? What cam came out of it and what oil are you running? I agree with a little more timing as well. My Lunati cammed (10120701) SB 350 likes 15-16 initial and 35+ all in at 3500. With that said and all cam lobes still intact with a zinc ladened oil, then you can bet it's the carb. Your previous cam may not have revealed a weak shot or even a rich shot where the new cam with a different vacuum signal and grind would.
__________________
Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American" |
08-28-2016, 10:21 AM | #9 |
Senior Member
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
|
Re: Sbc Falling on its face..
The cam dicatates how the engine will perform. Its the heart of the engine. The time the valves stay open and how far they open is dictated by the camshaft. That directly affects the air/fuel requirements and timing requirements of the engine. Its common and stock engines are very forgiving because they are made in a way to work well with almost anything you bolt to them.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member. |
08-28-2016, 05:12 PM | #10 | |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Re: Sbc Falling on its face..
Quote:
I just came in from checking things and found I forgot to tighten the dizzy bolt and it walked so reset at 15 initial and 34-35 total at 3500! I think my weights in the dizzy are loose or sticking so I will address that later. I also found out my fuel regulator was stuck and pushing 7.5# fuel pressure to the carb and the back float bowl was way low and the front was a touch... Big swing so next time it's out of the trailer I will see what she acts like! Next thing I will be changing to another carb built by a friend of mine with a speed shop.
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
|
09-01-2016, 09:35 AM | #11 | |
Senior Member
Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
|
Re: Sbc Falling on its face..
Quote:
__________________
Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American" |
|
09-01-2016, 10:21 AM | #12 |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Re: Sbc Falling on its face..
Maybe this weekend I will get it out of the trailer...
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
09-03-2016, 03:39 PM | #13 |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Re: Sbc Falling on its face..
Well on to the next attempt to fix... Plugs, wires, cap and rotor and if she still does it I'm going to buy a new carb or just say f it and go FI!!! Damn thing ran better with a flat cam!!!
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
09-03-2016, 07:54 PM | #14 |
Senior Member
Join Date: Oct 2014
Location: Eagle, ID
Posts: 2,953
|
Re: Sbc Falling on its face..
|
09-03-2016, 09:52 PM | #15 |
Senior Member
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
|
Re: Sbc Falling on its face..
That's because its an edelbrock carb.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member. |
09-04-2016, 12:10 AM | #16 |
Post Whore
Join Date: Mar 2013
Location: Southern Oregon
Posts: 10,384
|
Re: Sbc Falling on its face..
Still don't get what the problem with eddys are. Never had an issue with mine. Only had an issue when a stinkin fuel filter was plugged solid! Holleys are known to nasal leak like a water fall so be prepared to sit and crank on it for hours when things are hot. After using my eddy for 6 years I am now starting to get a little nasal leakage, but...turn the pump off and let the motor idle for a bit and all seems fine. That carb was way cheaper and worked like a top out of the box. 600 cfm 1405. Back when they were $290 and the same Holley was well over $300.
__________________
1966 Chevy C10 "Project Two Tone" http://67-72chevytrucks.com/vboard/s...d.php?t=596643 1964 GMC "Crustine" semi-build:http://67-72chevytrucks.com/vboard/s...d.php?t=665056 My youtube channel. Username "Military Chevy": https://www.youtube.com/channel/UC_h...fzpcUXyK_5-uiw |
09-04-2016, 12:24 AM | #17 |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Re: Sbc Falling on its face..
I've ran both and to me it's purely preference.... I'm not blaming the carb yet, wires and new dizzy first then carb but could also be an intake gasket leak or something like that but before I go that far "KISS" first
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
09-04-2016, 08:06 AM | #18 |
Registered User
Join Date: Oct 2013
Location: Maine
Posts: 2,340
|
Re: Sbc Falling on its face..
This is when it is nice to have multiple vehicles that you can swap known good carbs back and forth. If you are running the points ignition I would suspect that area. My truck came with an Eddy carb and I planned to change it but it has been working pretty darn good so it is still there after 5 years.
__________________
76 Chevy K20 76 GMC K15 77 Chevy C10 77 Chevy K10 |
09-04-2016, 10:21 AM | #19 |
Registered User
Join Date: Mar 2002
Location: Forney TX
Posts: 4,512
|
Re: Sbc Falling on its face..
I'm running an old Hei dizzy with mad hidden module...
__________________
Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274 |
Bookmarks |
|
|