Engine details: Holley 1920 rebuilt 11/11, Autolite 66 plugs (13,000 miles), 89-93 fuel, oil changes 2500-3000 miles, new PCV, new carb and intake gaskets.

Valve lash.

I saw the valve lash threads but some still don't answer some questions I have. I understand the specs and that the engine should (preferably) be running while the adjustments are being made. I know the sixes of wrenches I need and all that but....

1) What idle speed should the car be running at? How do I go about getting to it? Obviously the idle speed screws but how do I adjust the A/F ratio to keep the car running as smoothly as possible without flooding it, detonating, stalling?

2) Why is the procedure not in the service guide? Were soild tappet engines from the factory more common in 1970, so it was a given?

3) Just to be safe, I have this so rhythmic clickety-clack when the engine is cold, which goes away somewhat when hot, but still noticable. Sometimes sounds like a valve slamming shut over and over. Are these the rocker arms hitting the valves too hard? Is this the sign that the engine needs adjustment? I ask because the car seems to have fair power off the line but this rattling from the engine on acceleration is annoying and worrysome.

Carburetor issues.

1) Car drives fairly well but sometimes when I drive it up to a redlight, under normal braking, after I stop the car shakes and rattles the preheater door, sometimes it idles smooth. It does it randomly, or if the car idles in gear hot or cold for more than 3 minutes. For sure it does this after coming to a halt after a panic stop. I think it may be the carb throttle shaft? It leaks fuel at the shaft when I pump the carb 2-3 times.
Any ideas?

2) The car likes to hesitate on acceleration after pulling out of the gas station sometimes, seems to be doing better on this now, but it is cold, I think it may be a heat issue. It has never died, but it has wanted to sometimes, I've saved it by feathering the throttle until it catches.

Cooling issues.

1) Car was dangerously close to overheating on the hwy last summer speeds were from 65-75mph car ran at the "M" on the "TEMP" gauge. Car has torque drive 4blade 18" fan and a 19" radiator. What could it be? Takes forever to warm up in winter, and temp gauge seems low, car has grille restrictors at temps 40 degrees F and colder.

Any help would be appriciated, Thanks

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Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

[quote]1) What idle speed should the car be running at? How do I go about getting to it? Obviously the idle speed screws but how do I adjust the A/F ratio to keep the car running as smoothly as possible without flooding it, detonating, stalling?[/quote]

Adjust idle with “idle speed adjustment screwâ€￾ as slow as it can go without stalling or running rough; 500 or so rpm. Sometimes for whatever reason low enough idle cannot be obtained with idle adjustment screw. Bring idle rpm back up where it was, and retard timing to slow idle rpm.


[quote]2) Why is the procedure not in the service guide? Were solid tappet engines from the factory more common in 1970, so it was a given?[/quote]

By 1970 solid lifter engines were disappearing in favor of low maintenance hydraulic lifters from the big three’s domestic engines, Chrysler’s slant six mustered on into the early eighties before being fitted with hydraulic lifters.
[quote]


3) Just to be safe, I have this so rhythmic clickety-clack when the engine is cold, which goes away somewhat when hot, but still noticable. Sometimes sounds like a valve slamming shut over and over. Are these the rocker arms hitting the valves too hard? Is this the sign that the engine needs adjustment? I ask because the car seems to have fair power off the line but this rattling from the engine on acceleration is annoying and worrysome[/quote]

Sewing machine like clickety-clack is normal with properly adjusted lash. Noisy when cold, and diminishing valve train noise is a sign of out of spec (too loose) adjustment.

Clattering under acceleration may be spark knock caused by incorrect timing, sticking mechanical advance (governor) problems, and carbon build-up in combustion chamber; I’m assuming this is a stock engine. Other causes of rattling can be exhaust system hitting on something, bad engine & transmission mounts, loose flex plate, or something else when engine torques over under acceleration. Without hearing your rattling sound in person it is hard to narrow it down other than it could be just about anything.

I’ll let someone else that has experience with Holley 1920 help you, I have not laid hands on one.


[quote]1) Car was dangerously close to overheating on the hwy last summer speeds were from 65-75mph car ran at the "M" on the "TEMP" gauge. Car has torque drive 4blade 18" fan and a 19" radiator. What could it be? Takes forever to warm up in winter, and temp gauge seems low, car has grille restrictors at temps 40 degrees F and colder.[/quote]

If your car has the common horizontal gage cluster used 67 to 69+ normal temperature needle position would be straight up and down pointing at “Mâ€￾. If you have the later dash, I can’t help, as I have had zero face time in a car so equipped.

Slow warm-up indicates failed open thermostat that is cracked open when cold, and won’t fully open when hot. Engine may never reach operating temperature during short hops and cool ambient temperatures. Replace with standard 180 to 190 degree thermostat, flush system, and refill with 50/50 mix of antifreeze.

In contrast to today’s modern engines, a slant six is slower to reach full operating temperature by a few minutes due to more iron to heat, mechanical fan as opposed to electric that cycle on and off, and perhaps higher capacity of coolent.

If by grill restrictors you mean blocking air flow to radiator with cardboard or such; this is not needed, not even in a Maine winter if thermostat is functioning properly.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I checked the plugs and found that the person who performed a compression test only installed the plugs hand tight and that some were not even seated. So it goes without saying that the plugs overheated and the porcelain is blistered on all 6 plugs. Also the plugs were oil fouled.

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Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

Don't go to that mechanic again......

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I replaced them and torqued the plugs to 30 ft.-lbs. Car idles 100% better and a lot of ticking went away.

_________________
Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

That's good!
I hate other folks touching my engines.....I am picky and a neat freak.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I would've done the compression test myself but I haven't got shop air.

_________________
Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

You only need shop air for the leakdown test...compression test is just a hose and gauge you screw into the spark plug hole and crank the engine until it maxes out the reading...if the readings are really bad, then you do a leakdown...

-D.Idiot

That's what I meant both tests were performed less than 10% on all cylinders

_________________
Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

I tried my hand at a lash adjustment. It seemed to make a difference but only trivially. Intake set to.010" and exhaust set to. 020" with a hot engine. The ticking is still there but slightly quieter, still not as quiet as when the car was serviced last year.

_________________
Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.

OK, well now that I've had a chance to drive the car it idles super smooth, now to tackle the thermostat problem.

_________________
Leela: 1970 Dart 225 CID
Coulmn Shift TorqueFlite
7 1/4" Axle 2.76 Gears

Go ahead and save that weird car, the sedan, the 6 cylinder, the C-Body. If you want a big block musclecar and that's all you care about, your missing the point.