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440 that doesn't want to idle ... Tale as old as time


Well-Known Member
Local time
1:34 PM
Nov 9, 2014
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Richmond Virginia
So I have a very freshly built 440, the short block assembled at a reputable machine shop, heads resurface at another. Before I get into worrying about whether or not things are square and machined correct from that perspective, I want to see if anyone can bounce me some ideas for what the problem could be, maybe I've missed something.

It will start and run fine, revs up great, etc. But when it first starts it needs to warm up and this requires messing with the idle speed til it's hot for a steady idle, so I figure vacuum leak. The second and more important issue is that it runs fine in park and neutral, but immediately dies in reverse or drive. Holding the gas pedal a bit enables you to keep it running in forward or reverse gear, but the tires bite into my gravel driveway every time I do that so I'm tired of doing that. So this makes me think timing, or vacuum leak.

It's kind of an aggressive build I guess, 510 cam, new JE higher comp pistons, 6 pack rods, just a 750 vac secondary Holley. Initially it had an old torker intake that was suspect so I put a new performer RPM on it. New valley pan etc.

So I've checked the timing, checked for leaks, replaced spark plug wires, had Holley warranty me a new carb and checked the bowl levels, the mixture settings, new intake as stated, it is a points system with a brand new rebuild on the distributor and all the ignition seems fine, it runs great once it's gets into rpm.

Throw me out an idea, I'm getting pretty tired of this thing.
Maybe it wants a little more idle opening OR a little more static timing. Just my guess.
What is the initial timing set at? Have you checked for vacuum leaks?
What trans and converter are you running?
Idle open: maybe. I have no tach but I'm pretty sure of when too much is too much, and it needs too much to stay running in gear. Doesn't help I'm tuning on open manifolds at the moment.

Initial timing: 14~15ish.

Vacuum leaks: checked a million times now.

Trans and converter: the stock junk in the 727 that was bolted to the factory 361 motor.
What dwell reading are you getting?
What is the coil primary and secondary resistance?
Tuning with exhaust manifolds only you have no back pressure. As for looking to get idle when cold, good luck. Everything has to be spot on and should also be running with the choke closed and at higher idle setting.
And not getting it to idle in gear is probably caused by the converter being too tight for that camshaft. Just my guess. ruffcut
Intake: that's my underlying concern. I didn't really have an issue, but it wasn't a butter install either, and at this point I've done a couple 383s and 3 different intakes on this 440 and tbh they are all a pain so I tried to shrug that possibility off. Especially with it having had the same issue with the torker. But it's very possible. They are 452 heads. It's very annoying because the machine shop that did the short block was also supposed to do the heads but forgot so I had to take them elsewhere, and I feel like they would have addressed such an issue had they done them. Taking big blocks out in gravel driveway repeatedly starts to get old.
Ruffcut: respectful position with the lack of back pressure, but I've never had an issue with other motors doing the same. Certainly possible.

Also 100% on the idle at cold, but the changes needed are far too drastic for me to blame it on being cold alone. I've never run a choke on these motors and previous engines would idle easy on a winter morning first start. I do always make tune adjustments at temp.
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Just give it some more timing. Not with a light, but a smidgen by hand. Idle should pick up and smooth out

From there you can decide what to do with your advance curve etc.
Have a timing light on it and watch what happens when a helper holds the brake and drops it into gear.
torque converter!
510ish cam on a stock converter.....:poke:

I get where you're going here, but I don't think cam lift is the metric to gauge the appropriateness of a torque converter.
Certainly sounds like too much cam duration for the converter.
You checked for leaks by spraying carb cleaner around the intake to head joint and intake to carb joint and the idle never picks up? What is the vac reading hot in gear?

Converter comments first: this is my current concern, and not necessarily the converter itself but just the transmission in general. I think it's interesting this topic comes up so often but the one guy that usually brings it up gets shot down by everyone else. I plan to explore the issue. More on that at the bottom.

Reluctor gap is correct, points gap is correct. Distributor is a stock factory points that was rebuilt by Ignition Engineering in Anaheim CA, I had the service done, did not buy it secondhand. It is timed at about 14 degrees right now, I can roll it around from anywhere 10 to 20 and it'll do the same thing, maybe sometimes to different degrees of severity, but it's certainly not the underlying problem.

I am not changing to electronic ignition. I have every year's registration for this car since 1968 in a binder with all it's service history (California car til the late 90's when the original owner moved here to Virginia), including the thank you letter from Chrysler, owners manual, broadcast sheets, jack instructions, dealer provided certicard, AAA cards, first aid instructions, and so on and so on, and the car has 33k original miles. I want it to retain factory appearance despite the fact that I put a 440 in it. I know that probably sounds insane to a purist, but that's just how it is. I want it to look like a time capsule hot rod from the 60's.

There is no strong smell of fuel until an hour later, after I have been cranking away on it and checking timing over and over again and it's just p1ssed off and tired of taking in gas.

Everything has been sprayed. Everything, everywhere. No leaks unless it's internal, but I'd like to think a brand new Performer Rpm intake on a fully machined engine wouldn't give such an issue. Pulled off lines, replaced some hoses for no reason, sprayed the carb idle screw ports out and replaced them, 1.5 turns per usual as a base setting. Floats at correct setting. The 750 vac-sec Holley is also brand new, and I even made Holley give me a second one to determine it wasn't the issue.

I get it that it is a taller cam, I chose it based off of the Hot Rod magazine 440 build article since it's basically an improved version of the old 509, and understand it as the max that I think an engine could comfortably run with the stock valvetrain, but I have run a stock converter in a HP spec purple cam in a 383 and it did just fine. I do not know a whole lot about this though, and I understand 468/484 is not 507/510, so I am open to thoughts and suggestions.

Converter again: The reality of the build included a plan to have the converter replaced and the transmission gone through to support a bit more performance so I could have some fun with it, I had simply hoped I would be able to just drive the car to the shop doing that work instead of trailering and towing it all over gods green earth. When we jack up the rear end of the car and put it in gear it just jumps into gear and thats it, no idle issues. Obviously the wheels start spinning, but if you hot the brakes and the wheels comes to a stop, it stalls out... that makes me worried something inside the trans is deteriorating and causes the engine to stall when engaged when it should be able to spin freely. Bearing? As a final thought on that, I do have the big fat flex plate necessary to mate the cast crank external balanced engine to the trans. I can't imagine that would cause issues.

After I measure the electrical current at various spots, the next step is to pull the 727 here at home and do some exploring and learning and order a converter. It's a shame the 62-65 is the cable shift stuff, it would be so much easier to get a spare lever action 727 and go drop it off for a rebuild then just swap them out. Oh well.
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The car.