Hello,
I have a 1967 Dodge Charger with a 440 engine that's hard to start and doesn't want to idle very well. The original owner had the engine rebuilt, drove it around for a few years and then it sat in his garage for 29 years. I replaced the fuel tank, fuel pump, installed a new Holley Brawler carb., new plugs, points and wires, changed oil & filter and got it running. The engine starts hard and seems to have a low idle shake, but it will clear up under acceleration. I had the distributor checked by a race shop and it seems to be ok. I did a compression check and number 8 cylinder seems low to me.
Compression Check:
# 1 - 145 lbs. # 2 - 145 lbs. # 3 - 150 lbs. # 4 - 150 lbs. # 5 - 175 lbs. # 6 - 175 lbs. # 7 - 170 lbs. # 8 - 130 lbs.

When the engine is running about 900 RPM it's pulling around 12-13 inches of vacuum and acts like it has a vacuum leak. I have checked all the hoses and sprayed starting fluid around the intake manifold while the engine is running with noticeable change.
Could I have a valve sealing issue, a camshaft or lifter issue or something else?
Is there anything else to check before pulling the cylinder heads off and having them checked?

Thanks for any thoughts.

 

CB -

Basic stuff first, timing and/or crossed wires (firing order).
12-13 on the vac is normal for a mild performance cam.

Archer

 

Forgot to mention that new wires were installed and the timing was checked. The engine just seems to have a low idle miss almost like a spark plug wire has been pulled off. If you take the engine from idle to wide open throttle, it runs like it should. I just can't get it to idle and I am not 100 percent that the new carb. doesn't have some sort of issue. I am thinking about trying a different carb. to see if it makes any difference,

 

CB -

Still sounds electrical, but you could replace (or clean) the primary needle and seat on the carb or check the primary idle circuit.

Archer

 

Recheck it for vacuum leaks.....
Reset your timing to around 12* BTDC
On the Carb (Brawler 650CFM) Set all 4 corning Idle Air mixture screws 1 turn out to start with from being seated.... Also Check the Float Level... Center of the Site glass or just under center is my preference setting.
Warm up the engine and re-do the compression test, see if it stays the same??? ( just my onion, Those numbers don't look to out of wake to me)
Remember, You cant tune a bad engine !!!!!!!
Make sure the tuneup is good... Rotor, Cap, Wires, Coil, Spark Plugs, And Voltage to the Coil, Fuel is Good and Fresh?

 

I have re-checked everything on the engine and I still can't find anything. I did notice something that is somewhat puzzling to me during the diagnosis. The engine seems to shake and run really rough when it's first started. After it runs for 3-4 minutes, it will smooth out just a little bit. Once it gets warm enough to idle, the shaking movement isn't as bad. Could the engine have a bad lifter that leaks down and needs time to pump back up with oil? Could it also have a valve issue from sitting for 30 years and is part of the low compression on the number 8 cylinder? There could be multiple things going on with the engine and most likely needs to be pulled out of the car and taken apart.

What's a good set of aftermarket cylinder heads for the 440? The car wouldn't be driven very much and I don't need 700 hp.

 

IF you put a set of Cylinder heads on the engine, and it has a bad set of rings, the problem is going to be there. Just an fyi..
But, AFR's , 440 Source, Edelbrocks, all good stuff.

 

How low is the compression in number 8 cylinder? It could have stuck rings or a valve hanging open…
Sometimes you can use a bore scope and look at the top of the pistons and see if a stuck valve is hitting the piston…

 

Checklist for an engine misfire or poor idle.

Check for vacuum leaks. These can be sneaky and hard to find.

Check plugs, wires, cap, rotor, points and condenser, wiggle the rotor to make sure the distributor shaft isn’t worn out. Check the vacuum diaphragm if your distributor has one.

Check the carb. I am not a fan of Holley carbs. A Carter-type carb works better out-of-the-box. Set your timing with the vacuum advanced disconnected and plugged, and set your idle speed. Then adjust your fuel mixture screws with a vacuum gauge. Adjust them until you get the highest vacuum reading (the idle speed will increase), then set your curb idle and reconnect your vacuum advance.

Mechanically, check for flat cam lobes. Remove the valve covers and crank the engine with the coil disconnected. Make sure all the rocker arms are moving the same way. Check to make sure there is no play between the pushrods and rocker arms.