new rebuild running problem

[garth64]

Just rebuilt a 327/365 solid lifter engine; I'm having a problem keeping it running; I have statically set initial timing at 12-14* btdc, I adjusted the valves using Hinckleys write-up; the car starts and runs at about 500-600 rpm with a vacuum of about 10-12" hg, this is with the vacuum advance tube sucked on and clamped at full advance; after about 2 minutes of running, very erratically at that, the vacuum drops to abut 5-6" hg then stalls; while running, opening the throttle has no effect except to drop the vacuum which then increases again onc the throttle is released. any ideas or help would be appreciated. thanks.

 

[BLACK MOON]

Sounds like a vacum leak. Why is it 'sucked on and clamped at full advance'? If it's freshly rebuilt i'd drop the timing during break in. you don't want to see 'full' advance for a few hundred miles or at least several hours of break in running.

 

[garth64]

Without full advance it runs even worse; I checked for leaks with starter fluid around carb base and between int and heads, no change.

 

[JohnZ]

Just rebuilt a 327/365 solid lifter engine; I'm having a problem keeping it running; I have statically set initial timing at 12-14* btdc, I adjusted the valves using Hinckleys write-up; the car starts and runs at about 500-600 rpm with a vacuum of about 10-12" hg, this is with the vacuum advance tube sucked on and clamped at full advance; after about 2 minutes of running, very erratically at that, the vacuum drops to abut 5-6" hg then stalls; while running, opening the throttle has no effect except to drop the vacuum which then increases again onc the throttle is released. any ideas or help would be appreciated. thanks.

Sure sounds like a massive vacuum leak once it gets warm, plus a carb problem of some kind. It should be set to idle at about 900 rpm with the idle speed screw, and the idle mixture screws adjusted for maximum steady vacuum reading (normally 9"-10" Hg. at 900 with that cam); your static timing is fine, and the vacuum advance should be connected to full manifold vacuum, which will bring your idle timing to around 25*-29* (having the vacuum advance connected on a fresh engine won't hurt anything - if it's disconnected, the idle timing will be way retarded, it won't idle well at all, and the exhaust gas temps will go WAY up, and it'll probably overheat).

Have you set the dwell to 28*-32* BEFORE setting the initial timing?

What happens when you open the throttle? Do you get a pump shot from the squirters? If it just dies, something in the main metering system is plugged or it isn't getting any fuel. Float levels set correctly? Plug wires correctly indexed to the firing order at the cap?

 

[garth64]

John: I can't get idle to 900RPM; I set points at .018" gap before starting;I get a pump shot from the squirters but no increase in rpm; I've tested the carb base and manifold /head interface with starter fluid, no change in rpm; float levels adjusted(edelbrock 1406 carb); plug wires are indexed; thanks.

 

[BlackVette66]

You might try running a different carb that you know works. I had a similar situation when I had my carb rebuilt. I switched carbs and the car ran fine.
I finally found the problem with my oringinal carb after months of messing with it. The person who rebuilt it used the wrong base plate gasket.

 

[67l36driver]

Outer ring on harmonic damper slipped?

 

[garth64]

running problem

The carb I just rebuilt is a 1406 Edelbrock, the only other carb I have, which I just rebuilt is a Holley 2818 but I haven't run it yet.
I've been through adjusting the valves and timing many times and at TDC all the proper lines align. Thanks.

 

[JohnZ]

Grasping at straws here - is your heat riser valve working freely and not stuck shut? Are your exhaust crossover passages in the intake gaskets open or blocked?

 

[garth64]

running problem

John: I have spacer instead of heat riser valve; Intake gasket has open heat riser ports. thanks

 

[BarryK]

garth
i may be very wrong here, but when I was working on my car earlier this year it was recommended by many that I remove the heat riser valve and replace it with the spacer unit (like your car) but at the same time was told to than use the intake gaskets with the crossovers blocked.

I was told by doing this that it would take longer for the car to come up to temp but it would also keep today's fuels (compared to fuel from the 60's) from vaporising in the manifold by keeping the manifold temps down (if I understand what I was told correctly).

now, you have the heat riser valve removed but also have the crossovers open so I'm not sure how that's going to affect things.

 

[garth64]

running problem

What I've done in the mean time was set the static timing at about 20* btdc; the car started right-up and ran at about 1000 rpm, it stumbled a bit, ran a couple of minutes, then stalled; anything to do with carb, or advance mechanism?

 

[studiog]

My 2¢: As mentioned above, beg, borrow or steal another compatible carb (Edelbrock or Carter AFB) and gasket that you know works before you start pulling anything else apart... ie. intake manifold etc.

 

[c84/99y]

are you sure you have the valve lash set properly????

 

[garth64]

As an update: I finally got the car to run fairly decently last night; what I did was the following: I found that the distributor gear had .040" mainshaft clearance, it should be approx .007", so, I reshimed it; I also had too much of the carb transfer slots showing, so I had to back off the throttle setting; the car started right up and it pulled 10-14" hg; ran for a while then stalled, couldn't restart, had no spark, had volts to coil, and coil was Extremely hot. I have a new 091 coil installed, not sure of the resistor rating; I'll be checking that later today.

 

[garth64]

Forgot to mention: the centrifugal advance was inoperable due to lack of lubrication between main shaft and cam plate; also changed vacuum can to Eichlin 1810.

 

[Kid_Again]

I'll be darned. You fried your coil. I see a new, correct coil and a new, tested ballast resistor in your future.

 

[garth64]

May be just a shorted condensor; will be checking tonight; I've got the correct coil and ballast resistor installed now, both new.

 

[garth64]

Tested condensor, ballast resistor, and coil last night; condensor was not shorted, ballast resistor measured .4 ohms, coil measured 1.6 ohms and 11600 ohms; all appear in correct range; I'll be putting a higher ohm ballast resistor to save points in future; Is it possible for coil to "open" when it gets hot?

 

[67l36driver]

Is it possible for coil to "open" when it gets hot?

Coils can go 'open' or 'short' as they pick up heat from the underhood environment. That's why they are so sneaky. When the engine is cold things will operate normally untill you get to operating temperature. I chased a 'lean cruise miss' for several months before I changed coils and accidently found the problem.

Caution: Coils are oil filled and will overheat and burst if they short internally. Wear safety glasses.