I have a newly rebuilt 64 292 truck Y block engine that's been bored .060. Rods and crank are standard. Heads are "G" heads with new seats, valves, seals and springs and the exhausts are port matched to a set of Ram Horn exhaust manifolds. They also got a mild mill to ensure flatness. I sent my cam and lifters to Oregon Cam where it was ground (210/214 @ .050", 254/254 adv, ..445"/.456" lift(1.54:1 rocker), 108 lobe sep) and the lifters were resurfaced. I'm running the high lift Ford rockers 1.54 on new shafts fully pressurized. It's getting plenty of oil to them. It has a Ford "B" 4 barrel intake & I've had both a Holley 570 CFM and Holley 390 CFM carbs on the engine. I have installed a Pertronix III ignition module as well as their flame thrower III coil. If it matters I'm running a Ford C4 automatic using a Flat-O adapter. Hopefully that covers the basics. Oh and I've adjusted the valves hot at .019 and carb float levels on both carbs were set using the float windows.

My problem is the engine runs extremely rich with either carb, as in it's enough to run you outta the shop. I can't get the idle down below 850 and it still stumbles and dies aka won't hold an idle. After adjusting the idle screws and getting as good a distributor adjustment as possible my vacuum gauge is still below 15 inches of vacuum indicating late valve timing. If I put a timing light on it I'm somewhere in the neighborhood, there's no degrees that high, of 60° BTDC. Vacuum to the distributor is off and plugged. The engine runs pretty good off idle and can run 65 MPH no problem, oil and temp remain good. But if you stop it dies. Starts right up until the next time you need to stop. Probably have driven 50 miles or so.

I put the engine together and I'm as sure as an old man can be I installed the timing chain with the timing gears 12 pins apart. Is it possible for the engine to run 11 or 13 pins apart? Is there a way to tell without tearing the engine's timing cover off? It's kinda a PITA because it has a vintage air system all bolted to it.

I'm looking for any thoughts. I'm hoping I'm over looking something simple.

 

Just went out, pulled #1 spark plug ran #1 up on compression stroke a the timing mark is between TDC & 10° BTDC. I'm hoping this means the cam to crank timing is good.

 

Did you degree in the camshaft?

 

No Dennis I didn't but when I called Oregon Cam They said there really wasn't a need if you did the 12 pin alingment. I hate to say it but I don't know how to degree a cam anyway.

 

BJ, I have an Isky E4 cam. Ted said to install it 4 degrees advanced. I have a Rollmaster timing set with all the different keyways. To achieve 4 degrees advanced, I had to install it in the 4 degrees retarded slot. It was the 1st cam I ever degreed in. Every time I did it I came up with a different result. I took a break for 2 weeks and when I came back I got the right results.

Edit: I also have 15” of vacuum at idle, it increases with rpm’s.

 

Dennis, I'm not a cam guy so I don't know if mine is anything much more than stock. Again Oregon Cam said I should be at 17-18 inches vacuum. I tried pulling the distributor and reinstalling it. Same results.

 

You asked for any thoughts so here I go:
first thing is that your vacuum is low and the engine won't idle. Seems like there could be a vacuum leak somewhere besides the carb. A vacuum leak would cause poor idle.
Second thing, this one is a bit of a stretch, seems like the throttle plates are not fully closing on either carb. This could be a linkage problem... I said it was a stretch.
Lastly, the book I have on Y-blocks states that the timing, with vacuum port to the distributor closed off, should be 19-23 degrees BTDC at 2500rpm if you previously set the timing to 6 degrees BTDC at 600 rpm. This should help verify the correct timing.
More random thoughts:
If the timing chain or spark plug wires were off, I don't think you would be running 65 mph with no problems.
If you open the fast idle screw, I think the "rich" will be less rich as in running at 65mph with no problem. It can only be that rich if the carb is pumping way to much gas without the correct air/fuel mixture which should improve by opening the throttle. The main idea is that the air/fuel mixture is wrong which is my second thing above.
I hope something I stated above helps you. Or maybe someone else will add their own thoughts to this post.
Anyway, good luck.

 

Manfordman2,
Thanks for your thoughts. I would have agreed about the butterflies not being right if I'd have only tried one carb but one was brand new outta the box. Holley says they flow check EVERY carb. Yeah I know throwing money at a problem rarely fixes it. I've about consoled myself to pulling the engine so I can get at the timing cover and finally the timing chain. I've assembled several engines and never had a cam timing issue before but I'm leaning towards that being the problem.