Randra
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High jack away. It's funny you said that because I was thinking of bringing my Bee back to my builder also. But only if changing the intake gasket doesn't work.
Low vacuum
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Lionized
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Here's the specs. I'm adamant it should work fine for the street and have at least 14"Hg. I'm being told otherwise.
My builder feels quite confident he can get it running right.
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=717&sb=2
My builder feels quite confident he can get it running right.
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=717&sb=2
Randra
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idrivemopar
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Have you checked with another vacuum gauge? Just want to make sure the gauge is good before you start tearing things apart. I had a problem with trying to pull enough vacuum on my AC system, turns out my gauge was bad and once I put another one on, it was pulling correctly.
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Interesting to note that ours have the same centerline. I'm seriously considering swapping out my valley pan (again) and just using RTV. I've got a set of neoprene gaskets on the manifold side right now. Like you, I've checked scrupulously for leaks and found none but...
Randra
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I used Aviation form a gasket like I have in the past . But I used it sparingly so I wouldn't make a mess. But I guess it wasn't enough.
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Have you checked your plugs/done a plug read? What is your gap set at? Are you still running points or have you swapped to electronic?
I should be swapping my plugs right now but I'm bummed that I can't get the part I need to get my kickdown to properly adjust. I do have a new set of plugs ready to go that are gapped @40thou. Running full electronic ignition with a Chrome Box, Pertronix Flamethrower II coil and bypassed ballast.
miller
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If your pretty sure there's no vacuum leaks, first thing I'd do is a compression check. That would tell you if there's any problems 'inside' the engine...valves and the like. You want to do three 'hits' on each cylinder, reading the third hit.
If compression is good...I'd check carb mixture...but, not with a vacuum gauge. Actually both ways, using them for comparison. Talking about setting the mixture via the RPMs.
Using a tach, let the engine get to temp, at idle, and one mixture screw at a time, slowly back out the screw...watching the tach. RPMs should start falling. Results you want, is each mixture screw adjusted, until the highest RPM. At that point, too lean, or too rich, the RPMs will fall.
Set each mixture screw...for high RPM...then shut the engine off. Carefully, and gently, turn each screw in until they seat, getting an accurate count of turns. If there's any difference, split the difference, and adjust each screw to that number of turns.
Many times, you also have to re-adjust idle speed. If idle speed is too high, all a waste of time! Carb must be in the idle circuit, to adjust mixture.
With that number of turns known, you have a base, to compare to setting them, with a vacuum gauge. Engine has to be in good shape, using a vacuum gauge.
65wgn440
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To determine if it's a major vacuum leak causing your problem, with the engine idling completely close the choke plate and see if it causes engine to stall. If you don't have a choke, or a very loose fitting one, then use a LARGE (so it won't get sucked into engine) towel to block off air horn.
Randra
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Yep did that. It stalled.
Randra
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Good thinking on the compression test. I'll do that.
Randra
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No I didn't check the plugs yet. And I don't remember what I set the gap at. It was converted to electronic years ago. All is going to have to wait until next weekend.
Man, this sounds way too familiar...I see above that a new intake gasket didn't fix it, but I just went through this...swapped ignition parts, pans & gaskets, rebuilt and triple checked the carb(needed it anyway), drove me insane...ended up being a fitment issue with the stock style pan, if you're getting oil in the intake charge it can act like many different things..may be fine in your case but maybe give this a quick read? http://www.forbbodiesonly.com/moparforum/threads/valley-pan-lesson.130628/
moper
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Unless the builder blueprinted the block and then there's no way it's over 9:1 compression, and more than likely closer to 8.3:1. Which means the camshaft is a bit large for it. Do the compression test. If it's low, there's your problem. That cam, with the right parts and properly set up, may still not make 14" of vaccum in a 383. But it should get over 10, and a hell of a lot more than 5.
x2 what moper said, I currently have a cam slightly larger than yours and in my leaky valleypan motor I was getting 13-14"
Banzaiii67
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I had that same carb with a 110cl cam with about 9:1 compression, it's way was too much for a edelbrock 650.
I Purchased a Quickfuel 680 with 4 corner idle, now I don't have any vacuum at idle on the timed port, and about 12-13" on the manifold side.
Where are you measuring the vacuum? If it's on the timed port, your in the idle circuit it will never run correctly as long as you have vacuum on that port.
I Purchased a Quickfuel 680 with 4 corner idle, now I don't have any vacuum at idle on the timed port, and about 12-13" on the manifold side.
Where are you measuring the vacuum? If it's on the timed port, your in the idle circuit it will never run correctly as long as you have vacuum on that port.
Randra
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Vacuum is measured off the intake. The reason I went with the edelbrock is it's similar to the Original AVS. I've been thinking about going with the Holley 670. But I'm not sure that will cure my problems
383man
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If the gauge is bouncing up and down rapidly thats an eng mechanical problem. A vacum leak will just be low vacum and it may sweep a little but it wont bounce all over the place unless its a mechanical problem like a sticking valve or lifters with not enough bleed down as my buddy ran into that years ago when he milled his heads and still used the non adjustable rockers. I had a Dodge Van do that years ago as when it got hot the vacum gauge started jumping all over. That ended up being a hydraulic lifter that the wire retainer at the top had let the top lid of the lifter pop on top of the wire retainer so that lifter would not bleed down and when it got hot it held the valve open a little as heat exspansion held the valve open some as because the wire retainer was below the lifter cap it made it acty like a solid lifter. Ron
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