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By cbass139 - 13 Years Ago
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So I have the engine running a ton better, thanks to you guys, but still not perfect. It is a 292 with original 2 barrell holley and a electronic mallory vacuum advance dizzy. Now it bogs down in the low RPMs of 2nd gear, like when I am turning a corner or have to slow for a light but not go down to 1st. It doesnt really do it when I have the choke pulled out a little and the RPMs are a little higher so I dont think it is the carb any more. I am thinking it is the Advance so I got a new spring set and figure I will try out some different combo's, any suggestions? Or do you think it is something else?
Thanks in Advance,
Cbass
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By cbass139 - 13 Years Ago
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It is like somebody put a anchor on the truck between 1000 and 1500 RPMs in second gear and then releases it right at 1500. Crazy, sounds like the timing advance right?
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By The Master Cylinder - 13 Years Ago
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I don't know what was done in the past, but it sound to me like you are a little lean in the transition between idle and midrange. You mention it runs better with the choke slightly out... and a higher RPM.
Just my 1¢.
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By cbass139 - 13 Years Ago
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What can I do to fix the leanness (is that a word) during the transition? Also if this was the case wouldnt I have the same problem in first and third gears?
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By Pete 55Tbird - 13 Years Ago
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Cbass " So I have the engine running a ton better, thanks to you guys, but still not perfect. It is a 292 with original 2 barrell holley and a electronic mallory vacuum advance dizzy. Now it bogs down in the low RPMs of 2nd gear, like when I am turning a corner or have to slow for a light but not go down to 1st. It doesnt really do it when I have the choke pulled out a little and the RPMs are a little higher so I dont think it is the carb any more. I am thinking it is the Advance so I got a new spring set and figure I will try out some different combo's, any suggestions? Or do you think it is something else?" Something else. Without more information thats all you will get. How do you know the RPM, do you have a tach? Distributor advance at the low RPM you are saying it has the problem is very unlikely. And if it was it would be the same in all three gears not just second gear. How fast are you going and if you do have a tach what is the RPM range that the problem happens at? The carb has two circuits it runs through. Idle and transitions to main jet with the help of the accelerator pump shot of fuel. Is the pump from the squirters OK? Not enough data, Pete
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By rick55 - 13 Years Ago
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If it bogs in second gear does it bog in top gear at the same revs. It should.
This still sounds to me like you have the same problem you have had all along. Changing jets and whatever has affected it but it still remains. It still sounds too lean if you have to close the choke and raise the revs. Are you sure you don't have a vacuum leak. I think you addressed the transition slots when you had the first problem.
Regards
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By cbass139 - 13 Years Ago
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Yes I have a tach that is how I know that it is sluggish between 1000 and 1500 rpms and it is at low speeds like when you go around a corner, not when I am accelerating between 1st and 2nd. I guess I never have the truck that low in the rpm range in 3rd to know if it really does it then. I checked everything as far as the vacuum leak possibility goes and that first bog was only in first and it was fixed by getting the accelerator pump linkage dialed in.
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By Oldmics - 13 Years Ago
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More carb jet necessary. As long as there are NO vaccum leaks. Oldmics
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By Riz - 13 Years Ago
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I would agree I was working through a similar problem recently and was convinced it was timing until I found a small crack in the PCV hard line
When I was off the throttle and there were vacuum fluctuations it varied from rich to lean seemingly on its own, mine wanted to stall every time I came to a stop. I spent the better part of a weekend and a bottle of carb cleaner plugging everything I could think of before finding the crack (which actually expanded with heat)
Felt like a moron when I finally found it, but turned out to be a $5 PCV valve and some spare hose rather than something sinister.
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By cbass139 - 13 Years Ago
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I feel like I might have it but with the weather I had to call it quits for today. Hoping to get some time tomorrow. I did change out the springs on the dizzy as well as the vacuum hose and then dialed in the timing to be perfect with the carb. I double checked the accelerator linkage and the squirt and that was all good. I was out in the cold for about a hr, wish I could get some exhaust venting like we have at work in my garage so I could do it in the heated garage. Maybe tomorrow I can drive it around and make sure it is perfect.
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By Riz - 13 Years Ago
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One other thought ihad is that when it is especially cold and going on short trips I have had some issue with vapor condensation in the case that is not evaporated in the engine. ( i also have a restrictor in the manifold heat riser to avoid some carb boiling--i am running 3x2 holley 94s though) a regular 20 min blast at highway speed seems to stave this off. Maybe not related but just another thought.
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By cbass139 - 13 Years Ago
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Riz, thanks but I drive a 20 min blast on the highway every time I drive it so I dont think that is it. I hope I have it all dialed in but if not I will start working on the jetting because this is the only thing that I have not fully exhausted.
Thanks for all the help.
Cbass
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By cbass139 - 13 Years Ago
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So the saga continues, I went through and changed the springs on the dizzy (a lot snappier off the line) and went through the carb but still have a slight bog or anchor feel in second but it is a bit better so I might try changing the jets or the accelerator nozzle but the real problem is for the first time the radiator boiled over and shot water all over the engine compartment. I just checked the level and it was good last week and even when it was doing this the temp gauge was perfect in the middle. Any ideas on this?
Cbass
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By MoonShadow - 13 Years Ago
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Check the thermostat (might as well replace it while your in there). Then check for soft hoses. Sometimes they get soft and will suck shut at prolonged speed. Chuck
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By GREENBIRD56 - 13 Years Ago
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How full is it? The upper tank has to be your "overflow" can on an outfit like yours - before they invented the overflow can, space got left for thermal expansion. Make sure you have the large size of thermostat in there - there are some that are one inch diameter in a wide washer and some that are 1-1/2 with less washer and more hole. 
This photo shows the "Robertshaw" style of t-stat sold by Mr Gasket (and others) as a "high flow" type. The y-block uses the same size as the big block Chrysler, not the itty bitty Chebby part. This one has been drilled for three x 3/16 bypass holes. 
If you provide this port fror water to go to the radiator at start-up, then you can put a restriction in the little bypass hose beneath the t-stat housing. Use a 3/8 brass pipe plug with a 3/16 air bleed hole it it. Just insert it in the hose - it can't escape. The bypass hose is a direct "short" around the radiator, the size of a garden hose - this tones that down a bit.
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By cbass139 - 13 Years Ago
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Steve, what do you mean by upper tank? How do I know if it is too full? what distance from the top when looking in the radiator should it be? Also, did you drill out the bypass yourself? I am not sure I understand what you are explaining with those holes. Thanks for the help.
Cbass
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By GREENBIRD56 - 13 Years Ago
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Upper "tank" of the radiator - above the cooling tubes. I don't know how much room you need in the truck. Water flows through the engine - comes out the front of the intake manifold via the thermostat - if its warm enough to be open and controlling the water flow. If the engine is cold and the t-stat is closed - there is a little 5/8 hose directly beneath the t-stat that allows water to "bypass" directly back into the suction side of the water pump. This passage is open all of the time and very efficient at moving water - even when its 100° outside, this passage is short circuiting water - directly bypassing the radiator. You can cut down on the amount of "bypass" water by fitting the 3/8 plug and orfice into the little hose - but....at start-up, before the engine makes enough heat to open the thermostat - some water has to flow. The three holes allow the water to go to the radiator and the pump is not "dead headed". I drill the three holes myself - in a vise with my drill press, it isn't too difficult. Just don't damage the t-stat in the process. No doubt about it - this will slow engine warm-up. Do you have the cross-over exhaust pipe in front of the engine? Is the warm up valve for it allowing exhaust to flow - or forcing a lot of exhaust under the carb?
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By cbass139 - 13 Years Ago
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Ok, got it. I do have the cross over but I am not sure if it is opening or not and sending it under the carb. There a way of knowing besides the obvious of looking at the valve control?
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By Pete 55Tbird - 13 Years Ago
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You wrote " So the saga continues, I went through and changed the springs on the dizzy (a lot snappier off the line) and went through the carb but still have a slight bog or anchor feel in second but it is a bit better so I might try changing the jets or the accelerator nozzle but the real problem is for the first time the radiator boiled over and shot water all over the engine compartment. I just checked the level and it was good last week and even when it was doing this the temp gauge was perfect in the middle. Any ideas on this?" FIRST IDEA - the temp gage is not reading right, it boiled over. SECOND IDEA - identify what the problem is, then fix it. THIRD IDEA - provide a lot more infomation.
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By cbass139 - 13 Years Ago
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Very helpful Pete, thank you. fix the problem, cant believe I didnt think of that. What "more" info would you like? I am sorry but there are so many people on here that are very helpful and I thank them all but this kind of answer is worthless. I think if you go back and read the whole thread and not just the last one you will see that there should be a good amount of information, maybe not everything you need but if there is something else please ask. Everybody else has asked if there was something I left out and I have provided it and we are moving on fixing the problem, thanks again to all of you. Pete please stop posting on any of my threads because I dont need this kind of a time waste. Thanks for nothing.
Cbass
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By Hoosier Hurricane - 13 Years Ago
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I just read an article in the Studebaker Club magazine written by a Professional Engineer. He talked about ethanol laced gasoline. He said alcohol produces 34% less power per pound than gasoline, so you need to burn 34% more of it to get equal power. So with the 10% alcohol laced gas we get here in the midwest, our engine is automatically 3.4% lean. So bigger jets are required to get the same power as pure gasoline, with the resulting 3.4% loss of fuel mileage. And now the government has approved 15% alcohol in the gasoliine.
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By cbass139 - 13 Years Ago
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Is that true? Not only do we have to endure winter but we get screwed in the power department. I had to order the Jets and they are supposed to be here tomorrow, in the mean time I hope to get some time today to search down the thermostat/temp. gauge problem. I think I will start by seeing if I have the tank overfilled in the first place. Thanks for the info and I will let you know how it all goes after the weekend.
Cbass
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By GREENBIRD56 - 13 Years Ago
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To "complement" the alcohol / fuel situation we also find that the Viton tipped Holley needle and seat arrangement in most / many of the carbs we run - hate alcohol. They get sticky and the float level changes. If the float level drops - its virtually the same as switching to a smaller jet. Holley sells the steel needle and seat arrangement for alcohol fuel systems - it solves the sticky situation right away. As to water flow - there is a thread buried on here where our frend Nate - "BIG" - found that his impellor had rusted away to nothing and was not pumping anything. Do you see movement in the top tank of the rad when you have the cap off?
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By cbass139 - 13 Years Ago
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Ok, one test drive down and it was fantastic. I went ahead and replaced the thermostat and the level of the fluids to fix the boil over problem. I guess I had unplugged the temp. gauge last time I was under the hood so that is fixed as well. I took the dizzy out and went back to the springs I had in it and also changed the MSD dizzy curb limitor from 21 to 25. I took the carb apart and went from 50 main jets to 58. I made sure the float level was perfect, think it was a little low so that was not helping. Then I tuned the timing and carb using the vacuum gauge method. Like I said I took it for a quick drive and it was amazing. I am taking it for a longer drive in 15 min and if anything changes I will let you all know, otherwise I thank you all for all the help it is just amazing what I have learned and how much better it drives even from when I started.
Thanks
Cbass
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