First thing: Look at those plugs!
D/W
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| Engine missing or bogging @ mid range accelration https://www.slantsix.org/forum/viewtopic.php?t=16076 |
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| Author: | choppertruck [ Mon Feb 06, 2006 9:09 pm ] |
| Post subject: | Engine missing or bogging @ mid range accelration |
Running a new Holley 2bbl 350cfm, Clifford manifold and exhaust headers. New plugs @.035, new plug wires, new distributor, points, cap & rotor. timing@ 12BTDC @500rpm. schneider cam 132 grind .300lift 224duration also the distributor has a slight wabble at all rpm ranges . We have tried many different ttimingchanges and have tuned the carb countless times but the engine still falls flat mid range and clears up with full tthrottle No power mid range at all, sounds like a sputter through the carb but cant determine if it is ignition or carb problems. We have not gone through a valve adjustment but that is the next step. Note the compression is 120lbs per cylinder. Engine only has 15000 to 20000 mile on a complete pro rebuild. |
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| Author: | Dennis Weaver [ Mon Feb 06, 2006 9:15 pm ] |
| Post subject: | |
What do the plugs look like? I'd bet anything that Holley is crapping up the plugs... D/W |
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| Author: | argentina-slantsixer [ Tue Feb 07, 2006 3:02 am ] |
| Post subject: | |
could be small jets, maybe if you increase the rate of your power valve (say 8.5 or 10.5"Hg) you can cure it. |
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| Author: | Charrlie_S [ Tue Feb 07, 2006 5:19 am ] |
| Post subject: | |
Take a look down the carb barrels, while running the engine about 2000 rpm steady state. See if there is fuel being pulled out of the pump shooters. This is a common problem with the holley 4412 carb. Will run way too rich at cruise. Drove me nuts. |
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| Author: | DusterIdiot [ Tue Feb 07, 2006 7:39 am ] |
| Post subject: | Errr...the simple question. |
Which distributor did you use? you said the dist has a wobble at all rpm ranges...now is this from the balancer ring slipping, or did you use a MP distributor???? You may need to do a respring for the 'street' to keep the timing from 'bouncing' due to light springs, then I think Charrlie has the next one, if it's pulling out of the pump nozzles you need to get a heavier shooter needle/weight (this happens if the shooter is bigger than 32 sometimes on high vacc. engines). You also need to hook up a vacc. gauge and see if the 'lean out' occurs at a certain spot, then see if the PV needs to be lowered from 6.5 to 7,8,10. let us know more when you get a chance to post. -d.Idiot |
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| Author: | Dennis Weaver [ Tue Feb 07, 2006 8:04 am ] |
| Post subject: | |
First thing: Look at those plugs! D/W |
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| Author: | choppertruck [ Tue Feb 07, 2006 6:37 pm ] |
| Post subject: | |
Adjusted the valves intake .010 exhaust .020 did help the power a little. Plugs look good except for #6- running rich, carbon, no oil. Checked plug wire, working, getting spark. Looked down carb @ 2000rpm, some dripping from pump nozzles, backed the accelerator pump off until dripping stopped. Running the Holley 2300 part# 0-7448 carb. Ran better till plug fouled again (used new plug). Will run fine on level ground. Problems start with inclined roadway, under load. Picked up a stock replacement distributor @ NAPA not fimfamiliarth MP distributor. |
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| Author: | Jeb [ Tue Feb 07, 2006 6:50 pm ] |
| Post subject: | |
Sounds like your floats are set a wee bit too high. |
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| Author: | Dennis Weaver [ Wed Feb 08, 2006 10:35 am ] |
| Post subject: | |
Rejet carb leaner. Possibly try hotter plugs in 1 and 6 hole. D/W |
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| Author: | Doctor Dodge [ Wed Feb 08, 2006 10:48 pm ] |
| Post subject: | |
It could be a blown or loose power valve, also loose main jet(s) or a incorrect or leaking metering block gasket. What is the history on the carb? DD |
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| Author: | choppertruck [ Wed Feb 08, 2006 10:55 pm ] |
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Carb is fresh out of the box, new. |
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| Author: | dakight [ Thu Feb 09, 2006 4:30 am ] |
| Post subject: | |
New new, or new "remanufactured?" |
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| Author: | choppertruck [ Thu Feb 09, 2006 10:23 pm ] |
| Post subject: | Carb and Plugs |
New new on the carb I am running Autolite platinum 66 the hottest I can find around here. |
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| Author: | Dennis Weaver [ Fri Feb 10, 2006 6:05 am ] |
| Post subject: | Re: Carb and Plugs |
Quote: New new on the carb
Yeoww, that's pretty hot already. I am running Autolite platinum 66 the hottest I can find around here. Of course, I hate Autolite plugs, they tend to foul out a lot quicker than others in my experience in any heat range. I'm running Accels (jap made - NGK?) in my Duster - don't remember the numbers, but equivalent to RV12YC Champion on 2-3-4-5 and RV14YC on 1-6 (yours would require an "N" style plug, I have the tapered seat head which uses the "V"). On a stock application like my Valiant, I run RN12YC throughout (or equivalent). D/W |
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