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| intake leak https://slantsix.org/forum/viewtopic.php?t=57196 |
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| Author: | camiking23 [ Fri Mar 06, 2015 12:16 pm ] |
| Post subject: | |
doing my best with Answering the questions. Engine was sitting on a stand for 6 months But yes that's what i mean by fireball it was doing before I set #1 again. |
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| Author: | camiking23 [ Fri Mar 06, 2015 12:35 pm ] |
| Post subject: | |
If its 180 off do I fix it by removing the distributor and rotating it 180 degrees and placing it back in |
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| Author: | '67 Dart 270 [ Fri Mar 06, 2015 12:57 pm ] |
| Post subject: | 180 out |
You can do that yes. With the distributor cap off, take note of where the button is pointing. Pull the distributor out, rotate the button 180 degrees, then reinsert. Before you mess with the timing more, I would try the dumping some gas down the carb first, see if it fires up, if it's a fuel issue. brian |
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| Author: | nm9stheham [ Fri Mar 06, 2015 12:57 pm ] |
| Post subject: | |
Just rotate the shaft 180 degrees when you pull up the distributor body. So was the engine rebuilt? (Sorry if I have not gathered up all the early info...) How hard is it for you to get off the valve cover? It generally takes just a few minutes. With that off, you can be 100% sure of the timing. With the damper mark at 0 crank degrees, either the #1 or #6 valve pair should be at overlap, where the intake is starting to open just as the exhaust is finishing closing. See which is at overlap and set the distributor rotor to point at the other one; i.e., if #6 is at overlap, point the rotor at #1. To fine tune the timing, next adjust the distributor body position so that if you rotate the distributor body a tiny bit counterclockwise, the points are just starting to open. That will get you pretty darned close on timing. This is the procedure that I have used for a few decades on new builds and always gets timing close at start-up. This should eliminate that variable. |
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| Author: | Reed [ Fri Mar 06, 2015 1:14 pm ] |
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Quote: From the video, it sounds to be firing on a couple of cylinders. So spark is likely there.
I concur. I am going to go so far as to say that you likely have spark on all cylinders. That cranking pattern sounds to me like a classic case of the timing being too far retarded to allow the motor to start.Quote: I would pour a small cap full of fresh gas straight down the carb throat and immediately crank it; if it fires up for a few seconds and then dies, you have a fuel problem. If it backfires, then the spark timing is all screwed up or the vales are somehow not in sync. Since you say you have had smoke and (maybe?) backfires, that is a sign of messed up timing or valves sticking/hanging open.
I concur with this, mostly. I don't recommend dumping gas down the carb throat. A much better method of ensuring that you have a float bowl full of flammable stuff for the engine to consume is to shoot carb cleaner down the bowl vent valve for about 20 senconds before you try and start the motor.Backfires out of the carb are usually caused by the base timing being way out of adjustment. Quote: What do you mean by 180 degrees out?
Quote: you might just be 180 degrees out. i.e. you're trying to spark at the top of the exhaust stroke.
The pistons in a slant six engine move up and down in the bores in matched pars. 1 and 6, 2 and 5, 3 and 4. This means that when 1 is at TDC 6 is also at TDC. The same goes for 2 and 5 and 3 and 4. Now, while 1 and 6 might both be at TDC, they are at TDC on different strokes. Specifically, they are 180 degrees out from each other in the four stroke cycle. In other words, if 1 is at TDC on the compression stroke 6 is at TDC on the exhaust stroke (remember, suck-squash- bang-blow). This means that it is very possible for you to put 1 at TDC but have it be at TDC on the exhaust stroke rather than on the compression stroke. I have done this many times. Usually the engine won't start, but not always. I once got a 76 Volare for very cheap because the seller said it lacked power on the highway. Turns out the selled did a tune up and got the plug wire firing orde ron the cap right but installed the distributor cap 180 degrees off. The car ran, it just was gutless. By saying you have the timing 180 degrees off, he is saying that you should try putting the distributor rotor 180 degrees opposite of where it is pointing now. This effectively shifts the "phase" of the timning 180 degrees. So if you had cylinder 1 firing at TDC on the exhaust stroke it would now be firing at TDC on the compression stroke. However, before rotating the rotor 180 degrees, I recommend giving the distributor a slight counter-clockwise twist, like about 10 degrees, and trying to start it again. |
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| Author: | '67 Dart 270 [ Fri Mar 06, 2015 2:27 pm ] |
| Post subject: | video |
I agree with Reed, I would try advancing the timing first, see if you get better results. Not too far, just turn it counter clockwise about 1/8 to a 1/4 inch, try it again. If the first nudge doesn't do it, then maybe rotate it more and try again. Post a video of the result if it's any different at all from the first video - that might tell us something. brian |
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| Author: | camiking23 [ Sun Mar 08, 2015 6:48 am ] |
| Post subject: | update |
Ok. So i set the timing. And on the first try with fresh gas in the carb it cranked right up. But now i have other issues. First the 2bbl. Choke is open and won't stay in a position for idle so it dies because of too much air. And when i have it idling (from holding the choke almost closed) it is smooth but sounds to fast. And when i go to hit the gas it acts like tge gas is bad it starts vibrating roughly and i see lots of exhaust smoke only when i hit the gas. And in gear it seems to want to move on its on and stil wants to die if i try to accelerate |
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| Author: | Reed [ Sun Mar 08, 2015 9:28 am ] |
| Post subject: | |
Sounds like you need to spend some time adjusting the choke settings, fast and curb idle speed setting, and the fuel mixture on the carb. What carburetor did you put on the four barrel intake you installed? |
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| Author: | '67 Dart 270 [ Sun Mar 08, 2015 10:32 am ] |
| Post subject: | great! |
You might want to try that 4bbl again, if all that linkage and such was worked out already, maybe that carb is ready to go or has less issues? b |
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| Author: | camiking23 [ Mon Mar 09, 2015 4:53 pm ] |
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4bbl works but seems to rich. And there still is that small gap between exhaust and intake. And idles fine in park or neutral but in drive or reverse dies and if I try holding it to the floor it skips badly or jus tapping the gas while in gear it wants to die |
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| Author: | camiking23 [ Mon Mar 09, 2015 5:11 pm ] |
| Post subject: | Reeds Question |
It's a Holley 390 with electric choke. And another thing the choke stays open doesn't close. |
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| Author: | camiking23 [ Tue Mar 10, 2015 9:40 am ] |
| Post subject: | |
https://www.youtube.com/watch?v=X_TuRc4ZlEg Video of this |
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| Author: | Reed [ Tue Mar 10, 2015 9:45 am ] |
| Post subject: | |
Like I said, and it goes double if you have a Holley, it sounds like you need to spend some time tuning the carb to your motor. The choke should close when the motor is cold. If it doesn't you have a problem. The engine shouldn't die when you step on the gas. If it does, you have a problem. Check the accelerator pump shot and try and get an idle vacuum reading. Beyond that, I can't help you with tuning your Holley carb. I have never had good luck with Holleys, mainly because I have been too impatient to learn all the intricacies of tuning them. Other people have good success with them and can help you more than I. |
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| Author: | neilskiw [ Tue Mar 10, 2015 10:31 am ] |
| Post subject: | carb tuning |
Reed has you on the right track. Adjusting the choke should be done stone cold. It needs to be closed or mostly closed to limit the quantity of air, thereby creating a rich fuel/air mixture for the cold engine. That vid where you crack the throttle in gear, and it falls on its face and dies... Is the engine warmed up to proper operating temperature? If not, that is contributing to the problem because a cold engine requires a richer fuel mixture. When you crack the throttle, you let a bunch of air into the system. If your accelerator pump does not squirt a healthy dose of gas into the system at the same moment.... the engine will fall on its face and die like yours. That said, if your ignition timing is off a bunch, that will contribute to the problem. Since the engine idles... warm it up real good, cap the vacuum advance if so equipped, and set the ignition timing. Once you have eliminated ignition as a possible contributor, then you can concentrate on adjusting a Holley 390. There will be a lot to learn about that, I'm sure. But it will be worth the effort. Hey, it's running! you're half way there! Keep digging! |
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| Author: | '67 Dart 270 [ Tue Mar 10, 2015 10:38 am ] |
| Post subject: | glad you have it running... |
I agree with Reed, it sounds like you have a fuel and/or vacuum issue. Is the choke still closed or partly closed when it was running there in the video? It's not called a "choke" for nothing, that would keep it from running when you push on the gas. With the choke open, as Reed suggested, you should move the throttle linkage and look down in the carb (doesn't have to be running) to see if gas is squirting in when you move the throttle. Next time you have it idling, make sure the choke is open, then try the throttle, see if it's the same result. Send us a video of you doing that, also if you have time, include some closer shots of the manifolds, perhaps we can see if you have a major leak somewhere. It was doing the same thing with the 2bbl, right? brian |
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