Just can't get her to run right. Any suggestions from this forum would be welcome. Replaced trashed 360 in my '68 F100 with a 390. Truck is an auto with a C6 in it.

Bought a running pull, tore it down to the core and verified crank/pistons/cam. Replaced timing chain. Reassembled with freshly machined heads. Edelbrock intake and carb. Accel electronic ignition. The intake/carb/ignition were all off my 360 and ran perfect with zero issues.

After installing motor, it fired right up and went to a nice idle. Set the advance with a light to 10 degrees.

Truck starts and runs at idle. Pulls out smooth, and seems nice and smooth at low speeds. Once you move down the road.........at about 35 or 40 mph, it won't rev out at all. Kind of flattens out and won't rev. Has no power at all. Feels like it's missing, but hard to tell. Gets up to 55 or so.......and that's it. Won't go any faster.

Any ideas? Anything to look for?

 

Where is your total timing (initial+mechanical) set? and when is it "all in"?

I'd recommend 36-38 degrees total, all in around 2500-2800 rpms...

 

The accel is set to 20 mechanical, all in is at 2500. Weve run it all the way up 36 total. no real improvement.

 

Have you checked your fuel pump ? Might want to see if its putting out 6 to 8 lbs of pressure .

 

Fuel pump seems good. Looking from the top of the carb..........when I rev the engine, I can see gas flowing in the carb.

Sitting in park, running......the engine sounds perfect. Smooth idle. Sounds find reving it out.......you can't hear the problem without a load on it at all. Put it in drive.........it's smooth and runs great until about 40.........then just starts running like crap. Sometimes you can feel a distinct cutting in and out.

 

I just did the Mustang gas tank swap on mine , since swap it's been doing the same as yours i can putt around with no issues but if i nail gas it coughs and bogs . I traced it down to fuel starvation , I have a Glass fuel filter between carb and pump if i rev engine constant at 3500rpm i empty the fuel filter , so when vacuum secondaries open there's no gas . I just ordered a holley Black pump to fix .

 

2X Mike. I was thinking fuel pump or valves not adjusted right. Think gas, air, and spark.

 

Valve adjustment? I torqued the rocker arm shaft to the book value, checked each push rod for play.

When looking into the top of the carb and opening throttle until secondaries open.........how much fuel should I see pumping into the carb?

I pulled the #1 plug (I put brand new plugs in it). It's very white on the electrode, but some carbon already built up around the core.

Could it be timing? Would that exhibit these issues? I mechanically timed it before putting the heads on. Timing gears dot to dot, #1 piston at TDC, both lifters even. When I put it all together, flywheel installed with the TDC mark lined up perfectly. After installing heads, intake, and distributor......I rotated it around, and brought the #1 to TDC after the intake valve closed, and lined up the distributor rotor to #1 and installed the wires from there.

Seems like most feel fuel pump, so my next move will be fuel pump.

 

I agree this may be a fuel starvation issue (assuming the timing is dialed in correctly).

A stock fuel pump should put out anywhere from 5-9 psi, but keep in mind Eddy carbs don't like anymore than 5-6 psi tops...so a regulator may be required.

 

Yep. Everything pointing to fuel pump.

 

Where are you currently at with timing?

Still running 10 initial and 20 mechanical?

Stock FE's like 10-12 initial but if your motor is even slightly built they prefer upwards of 18-20 degrees initial...

Otherwise you're gonna have a dog of a motor on your hands.

 

I seek elucidation.
I do not have anything to offer about why the man's motor is not running well but I have a question about this "all in" phrase.
I am an old dragstrip guy. Maximum timing back in the day was done with a crank tape. All in was the sum of initial static advance plus the maximum advance that the plates in the distributor would allow plus what the vacuum advance would allow. The rule was that anything beyond 38 degrees total advance would take a Ford small block apart at rpms.
Can anybody here help this old timer understand the new terminology?

Semper Fi

 

It simply refers to what RPM the timing is "all in", depending on various spring tensions and weight combinations the timing can max out, i.e. be "all in" anywhere between 0 to 5000 rpms.

 

Not so simple, methinks.
"All in" seems to refer to the sum of static advance and mechanical advance. But the vacuum diaphram gets into the picture and contributes to the advance.
I was a four-speed ace and shifted under full throttle. Guys used to do the same with an "all in" of thirty-five degrees of mechanical timing. They would miss a shift, drop throttle, come back up hard when in gear and blow an engine. The mechanical "all in" did not account for the fact that the dropped throttle put full vacuum from the carb upper port to the advance plate, jerked timing to fifty or more degrees advance when the throttle reopened on the punch.
I am not trying to hijack the thread just advising that you must be careful with adding mechanical plus static, staying below thirty-five degrees on a high-revving V-8, ignoring vacuum advances.

 

CougarJohn. I believe what you are saying but I thought it was mechanical plus static also. At most throttle there would be no vacuum in intake or carb so therfore none at vacuum advance. So the V/A would not come in to play. Sorry for the steal guys.