![]() |
Hotrodders Bulletin Board
Home · Bulletin Board · Project Journals · Tech Article Wiki · Knowledge Base · Photo Gallery · Classifieds · Company Reviews · Calendar · T-Shirts |
|
||||||
|
|||||
![]() |
|
|
Thread Tools | Search this Thread |
|
#1
|
||||||
|
||||||
|
HELP!!!! Backfire...chevy 350
Long story short. I get good response and smooth acceleration out of the old beast in Neutral or Park, but put a load on it and WAMO I gat a backfire out the carb and (most assuredly beacuse of the backfire) loss of all engine function, then it's back to acceleration. This occurs somewhere around 3000 to 3500 RPM at over half throttle. Here's what I know about the engine as I have just recently bought the car and am learning by doing a whole lot of "well that didn't work......"
78 formula orig. 350 chevy 101 block .40 bore,2.02-1.60 327 camel hump 64cc heads,crane roller rockers,edelbrock performer carb,edelbrock torker 2 intake,b&m 3000 stahl converter,th400 trans w/b&m perf. kit and trans pack.10 bolt rear end w/ 3.73 gears,new bearings,seals,and gears.hooker super comp headers w/edelbrock mufflers.holley electric fuel pump,crane energizer cam and lifters 278 adv.dur.,467 gross lift.crane .500lift springs and manley valves. (I just put an edelbrock 750CFM, model # is 1407, carb) guy told me that I'm supposed to be 18 retarded on the timing, but I don't really believe that. Checked the initial and I'm at 18 advanced...hmmm.... mechanical tops out at 30 advanced, vacuum hose is hooked up to the full advance (haven't tested timed advance yet) and gives me only 4 extra deg. advanced. Anywhoo....that backfire is absolutely killing me and it's scaring the living bejesus out of me because I'm not sure I'm not doing damage somewhere. Oh and don't ask me if I'm getting ping or knock cause I can't even here myself going deaf. (There's no pipes on the car, just exhaust, and they end right under the seats.) Oh and I'm new here so Hello ME PS: how much would you estimate this guy put into this car? Last edited by interro1 : 07-05-2005 at 07:32 PM. |
|
#2
|
||||||
|
||||||
|
WELCOME TO THE BOARD
let me be the first on to welcome you here !!! what do you know about the timing chain?? if nothing then use a breaker bar on the crank shaft ( you might have to pull the plugs out) and also pop the dist cap off and rock the crank if the crank moves and the dist dont then its very likely the chain is stretched and done for. try timing it by ear or vacuum. could also try re adjusting the lifters but wait to see what kind of replies you get, there is a ton of more knowledgeable than me on this thread this place is freaking awesome again welcome rob sr66
__________________
"SlowRide66" "Illegitimis non carborundum" Don't let the bastards grind you down! Crankshaft Coalition Master List of Hotrodding Forums |
|
#3
|
||||||
|
||||||
|
Here comes the BUMP!!!!
buddy of mine said he thinks it's the points floating. I don't think the timing chain is toast, though it is possible, because the derned thing is brand new. thanks for the advice though...gonna go wiggle that buddy and see what happens. Any other ideas? |
|
#4
|
||||||
|
||||||
|
Quote:
did ur car do this when u first purchased it why did u replace carb well if u checked and verified timing next is distrib,and all component's concerning that. if still popping swap out carb. whenever i had popping like that distr was 180 degrees out but car ran very poor. park , drive or otherwise some timing event is wrong making it pop out carb make sure you take vacuum readings that will tell part of story Last edited by BigDawgsEatFirst : 07-06-2005 at 06:50 PM. |
|
#5
|
||||||
|
||||||
|
BINGO!!!!!!!!!!!!!!!!
You're the first person that has answered that question with the same relative answer as another.... That says to me that, that is where I will start. Thinking of swapping for HEI and going with electronic ignition. From what I've hear this makes life all the more simpler. And I like simple. Got points right now, any suggestions on a goor route to go with the distro and ignition? |
|
#6
|
||||||
|
||||||
|
take them points
and make 2 points when u throw them in the trash get a HEI and see what happens points are bad go HEI |
|
#7
|
||||||
|
||||||
|
Don't waste your time with all that other junk above.
First, you need to make sure the timing is right. An advance analyzing light makes this a lot easier. You want the total timing to be at 34o to 36o. You need to verify that is what you are getting. I like to run 16o to 18o initial advance. Running more initial will wake your engine combo up considerably. If you need any help doing this just ask. Most people on this site know how to do it. Then, if you still have a bog you need to work out the carb. Check your fuel filter and make sure it isn't clogged first. Again, most people on this site can help get the carb worked out. You need to start with a solid baseline otherwise you will end up doing goofy stuff like prying on the crankshaft to see the distributor play, or timing your engine by ear or by vacuum (never time your engine this way unless you want it to go boom). An electronic distributor would help. I wouldn't go HEI they aren't easy to curve, and the curve is where all the performance is. I personally prefer the Mallory Unilite because when installed correctly, it is extremely reliable, and it is easy to curve. The Edelbrock Torker II is a piss-poor intake. It makes less power all around than the RPM. You will see better results with an RPM. The Air Gap is the best dual plane intake. Or, if you decide to run better heads and a bigger cam later, the Victor Jr. would work well with your stall. Don't go the Victor Jr. route with what you have so far. |
|
#8
|
||||||
|
||||||
|
Still Going!!!
already had HEI I just didn't know it (I'm new to this engine deal),changed cap and rotor, still getting the derned backfire... old cap looked burnt and I had residue in the cap and on the weights (in another thread)
Car runs better though, which is good. the carb has already been swapped out from the old one, and car is still doing it. thinking maybe it could be the mech advance or something to do with it? or the vac advance? what's the best way to take vacuum readings? and what exactly am I loking for? thanks for the help so far. I'm sure I'll get this issue resolved before I take it to the rock quarry with some dynamite for a wrench. |
![]() |
Back to top |
| Thread Tools | Search this Thread |
|
|
Similar Threads for: "Small backfire from Carb...Chevy 350"
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| how strong is a 350 small block | ChevyVan | Engine | 18 | 01-04-2007 10:27 PM |
| 327 or 350 chevy (please no rookies) | chris oswalt | Engine | 16 | 12-11-2004 07:29 PM |
| Will this work? Chevy 305 Throttle Body w/ Chevy 350 | aberg12012 | Engine | 9 | 05-06-2004 11:28 PM |
| TBI Questions on a 93' Chevy FS 350 | IWANTMOREHP | Engine | 1 | 01-04-2004 12:42 PM |
| Installing Turbo 350 onto Chevy small block Help | ecarpener21 | Transmission - Rearend | 9 | 05-13-2003 09:17 PM |