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| EVEN WORSE POWER WITH 2BBL https://slantsix.org/forum/viewtopic.php?t=3315 |
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| Author: | Justin [ Sat Mar 02, 2002 7:27 am ] |
| Post subject: | EVEN WORSE POWER WITH 2BBL |
Ok same truck as befor 87 D150 Manual 4spd OD and this time its got a 2BBL intake & exhaust manifolds off of a 73(not sure what) And a 2BBL Holley off of a 84 D150 with a 318...Now ive tested vaccum and its around 18 on the manifold at 750RPM...I have a Carter 2BBL carb hear but its pretty rough so i'm not sure if i should rebuild it! This holley has NO ADJUSTMENT Screws on it so i can only adjust the idle...ok heres the results ...i have no choke on it and i live in canada....so its cold right now like -20 and i gotta pump the $#!+ outta it to start it...i let it warm up in the garage and when its warm its got awsome throttle responce...ok...back outta the drveway....seems ok...then start off in first just get rolling and smackit to the floor..ok no tirespin...only 3500RPM no more...UHHHH 2nd gear....the powers getting pretty bad...atleast 3/4 throttle to get it to move...then in 3rd gear i MUST put it to the floor and i can only get like 80k outta it...then in 4th...to bad i couldnt go through the floor for that cuz it just loses speed...so i advancce the timing tryit....no difference...ok i put a new fuel pump in...same thing...i havent changed the filter yet but thats to come...so now i'm really stumped...can anyone out there just gimmy some ideas..this thing was better power wise with my 1BBL on it!!!! THANK YOU Justin http://www.slantsix.com jdorosh2@autobahn.mb.ca |
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| Author: | Guy Reynolds [ Sat Mar 02, 2002 12:47 pm ] |
| Post subject: | Re: EVEN WORSE POWER WITH 2BBL |
Justin, It sounds like you are only getting about 1/2 throttle. Are you sure the throttle is opening all they way? I ran my '65 Barracuda for over a year and didn't realize that the butterflies were only opening about 3/4 of wide open. It felt like 20 more horsepower after I finally converted over to a cable throttle from the old torque rod and Rube Goldberg linkage I had made. Even that didn't want to open all the way until I got all of the right cable and auto trans downshift linkage parts. If you are getting WOT then maybe one barrel is not flowing fuel above idle. If this carb sat for a long time before you used it and hasn't been rebuilt then a really good dissassembly and cleaning job may cure that. Most Holleys do have fuel mixture screws but some like the model 6280 which was used on later 318s may have them behind blind plugs. I think to really clean one of these carbs you have to remove the plugs and take out the screws. The Holley manual advises not to, but I think that was just for the EPA here in the States. Anyway don't give up, the 2bbl really does make a bit more power. patGR@mediaone.net |
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| Author: | Justin [ Sat Mar 02, 2002 2:02 pm ] |
| Post subject: | OK NOW WHAT???? |
Ok if i belive its opening WOT but not sure yet...i'll check once i get home but even with that the carbs only been sitting a year and it is clean and even if it was the carb....WHY should i have to press the throttle more than a bit to get it to clime speed wise...Heck i hit the ditch oneday because of it...I was driving and i hit black ice and cuz i gotta press the throttle so much it spun me into the ditch..this thing got worse and i really do think its the carb this time but i dont know for sure...i spent 800 bucks ion a garage trying to figure this out!! I thought that maybe it could be the cat thats plugged adonno anymore...i just really need this truck running again....Thanks for ur help! Justin jdorosh2@autobahn.mb.ca |
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| Author: | Doctor Dodge (Doug Dutra) [ Sun Mar 03, 2002 9:03 am ] |
| Post subject: | Re: Find your way back to a good set-up |
Quote:
: Ok if i belive its opening WOT but not sure : yet...i'll check once i get home but even : with that the carbs only been sitting a year : and it is clean and even if it was the : carb....WHY should i have to press the : throttle more than a bit to get it to clime : speed wise... It could be a combination of issues, you just have to work through all the systems "one-by-one". My big question is if the engine is getting good spark advance. Do you have a timing light? ANY SL6 should have an initial timing setting Before TDC (start with 2 -4 degrees BTDC) and the mark should "Jump" quickly to at least 15 - 20 degrees BTDC right when you "crack-open" the throttle. Most will take 28 to 30 degrees "total" by 3000 RPM. The vacuum advance "pod" on the distributor has a lot of influance on "off the line" and part throttle operation "feel". If your system is all computer controlled, the same things apply but now you have to work with the computer and sensors to get the advance "curve" working right. Later "Smog" SL6 engines did not get much timing advance and that kills a lot of the power output. Bottomline, that carb. could be working fine. If the engine is not getting "crisp" spark advance, it will run crappy and take a long time to respond to any throttle inputs. DD |
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| Author: | Tim Keith [ Mon Mar 04, 2002 3:39 pm ] |
| Post subject: | Re: EVEN WORSE POWER WITH 2BBL |
My guess is you could have a manifold vacuum leak. I had similar problems with a Super Six setup with headers. tkeith@mindspring.com |
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| Author: | Winklovic [ Fri Mar 08, 2002 11:42 am ] |
| Post subject: | Re: EVEN WORSE POWER WITH 2BBL |
Quote:
: results ...i have no choke on it and i live : in canada....so its cold right now like -20 : and i gotta pump the $#!+ outta it to start : it. Justin, I believe you live in the same city I do and trying to run a vehicle without a choke in our climate is absolutely foolish. Get a choke on that carburator immediately. mopar@canoemail.com |
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| Author: | Chuck Rivers [ Thu Mar 28, 2002 11:34 pm ] |
| Post subject: | Re: EVEN WORSE POWER WITH 2BBL |
OK, this is a wild shot, but make sure that the exhaust is flowing freely. A clogged up muffler or Cat. converter will give you no power. If you can, you might make a short test run with the pipe disconnected. Chuck Quote:
: : Ok same truck as befor 87 D150 Manual 4spd OD : and this time its got a 2BBL intake & : exhaust manifolds off of a 73(not sure what) : And a 2BBL Holley off of a 84 D150 with a : 318...Now ive tested vaccum and its around : 18 on the manifold at 750RPM...I have a : Carter 2BBL carb hear but its pretty rough : so i'm not sure if i should rebuild it! This : holley has NO ADJUSTMENT Screws on it so i : can only adjust the idle...ok heres the : results ...i have no choke on it and i live : in canada....so its cold right now like -20 : and i gotta pump the $#!+ outta it to start : it...i let it warm up in the garage and when : its warm its got awsome throttle : responce...ok...back outta the : drveway....seems ok...then start off in : first just get rolling and smackit to the : floor..ok no tirespin...only 3500RPM no : more...UHHHH 2nd gear....the powers getting : pretty bad...atleast 3/4 throttle to get it : to move...then in 3rd gear i MUST put it to : the floor and i can only get like 80k outta : it...then in 4th...to bad i couldnt go : through the floor for that cuz it just loses : speed...so i advancce the timing tryit....no : difference...ok i put a new fuel pump : in...same thing...i havent changed the : filter yet but thats to come...so now i'm : really stumped...can anyone out there just : gimmy some ideas..this thing was better : power wise with my 1BBL on it!!!! : : THANK YOU : Justin webmaster@omnipages.com |
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