So...I changed the carb, tuned the idle to 15" of vacuum with all four mixture screws at 1/2 turn out and still have the same problem! I pulled a plug that was brand new with only 1 hour of run time and it was black and sooty. The soot is damp and can be wiped off with a rag. I'm now thinking I may have the same issue Chris was having with the valve seals. The problem is that I can't road test the car as it falls over as soon as I give it gas. They are easy enough the change, but still are a few hours of work. Before I do that does anyone have any other suggestions? And Brent if you are reading this thread, would you use these seals?

COMP Cams 529-16 - COMP Cams Valve Seals - Overview - SummitRacing.com

It really sounds like a blown power valve. Is the residue on the plugs oily or just wet or dry? Grind a plug into the palm of your hand and then attempt to wipe the residue from your palm. If it smears around it can generally be considered as oil. If it wipes off then it's fuel related.

Mark,
I know you've switched carbs back and forth trying to isolate this problem so this may or may not be relevant but I wanted to throw it out there anyway. When I first started my FRPP 351 crate motor I had a terrible time getting it to idle right. It was smoking like a diesel. What I did to zero in on it was to temporarily replace both power valves with plugs to take that fuel out of the equation. Then, even though they were new, ( brand new HP750 out of the box) I changed both needle and seat assemblies. You can clean them 'till you're blue in the face but sometimes they just stick.

From there I was able to get a clean idle by increasing the size of the idle air bleeds which really helped a bunch. Then I and added the power valves back one at a time but at a much lower opening point until I was sure everything was working right. Then I put the correct PVs back in. HTH.
Frank

Too much fuel pressure???

Ford Racing sent those seals to us and they did not work. We are trying the Crane Cams seals (white) next. I don't think your issue has to do with the seals though...

I also now understand that some of the earlier 427w engines from Ford had high volume oil pumps with small oil return holes in the head, This caused the valve covers to fill with oil. Ford's tech line is closed until Tuesday and I hope to get some answers then.

Post #1 you said the vacuum was bouncing between 13-15. Vacuum should not bounce. You also said the engine is missing. Are you sure it is running on all 8 cylinders? Are the plug wires correct for the firing order of the cam that is in the engine? Does the engine pop if you rev it hard?

I'm thinking that either the firing order you used is the wrong one or you have a couple wires crossed somewhere. Have a second person trace the plug wires and verify your results. Sometimes when you a so close to something you see what you believe, not what is there.

Good luck mate, i emailed them about this very thing, high volume oil pump and poor drain back hole in the head can cause the top end of the motor to flood with oil, didn't get much back from them on that one, i was told by a work shop in the US ( i won't mention names) that changing to a standard oil pump can help and has solved some oil burn problems on these 427's he has fitted.

Except for the fuel residue it kinda sounds like a loose intake manifold to heads. It might be sucking oil in when under power.

Post the part number of the intake manifold if you get a chance.

Edelbrock 7581.

With a lumpy cam, idle vacuum always bounces a bit and mine looks about right for the cam.

Thanks for all the ideas, please keep them coming!

My brother came down on Saturday, so I finally had a second pair of hands. Checked the spark, it was perfect as were the cap, rotor, box, etc. Checked the timing again and it looked good. However, with my brother in the car using the key to check the markings on the damper, we bumped it to TDC and then pulled the cap. The rotor was pointing at #3. Hmm...long story short, my timing was off because it was timed to the second set of marks on the balancer. Not sure how that happened as I was very thorough in setting it up, but sheet happens sometimes. The MSD 20 degrees of spark must have been enough to keep it running. Fixed that and the engine woke right up! All of this was masked by the red herring of my initial vacuum leak at the pcv connection to the carb.

Unfortunately, after it ran for a couple of minutes, it started blowing acrid blue smoke. If I shut it off, let it sit and restart it, it runs great for a few minutes and then starts blowing blue smoke. So much that it set the smoke detector off in the garage that is wired to all of them in the house! That was fun!

Based on information I've gathered since having this challenge, I've found this engine has two reported problems since it was introduced. Early engines employed a high volume oil pump, but the z heads have small oil return holes. Apparently, the valve covers will fill with oil and then the oil gets sucked past the valve seals. I can see how my symptoms could be the result of this problem. The second seems to be faulty valve seals. Both of these issues have been reported by several people on this and other forums, but I don't know Ford's response. Ford Tech reopens on Tuesday, so we will see what they have to say. Thanks for all the help so far, it is appreciated!

Jay, you said those Comp Cam seals didn't work. Is it that they didn't fit or didn't fix the problem? Also, which ones did fix the problem?

We have been too busy to try the new seals. I hope we find sometime tomorrow. If they do not work it is already approved for warranty service.

I will say, the comp cam seals they sent (bluish green) did not seem to be 11/32, more like 5/16. Ugh.

Looks like I was right.

Using the white seals from Crane did not solve the issue on the engine we are seeing these symptoms. It has 2,600 miles on it for reference. It is going back to Ford.

All fixed!

It was 54 degrees today, so I spent ah hour in the garage reviewing my problems. Last week I spoke to Marty at Ford Racing and he suggested that the pcv might be sucking oil into the intake. I changed my valve covers and even though the 427w covers that came with the engine were an inch taller, I checked clearance and no problems with the valve train. So, first thing I tried was removing the pcv. That seemd to fix it, but I got oil on the valvecovers. I then got the bright idea to add a 1" spacer under the valve covers and reinstalled the pcv. That did it! Set my timing to 16 BTDC, idle at 950 with the mixture screws out 1/2 turn each. This thing goes like stink!!!! Just spent the last hour driving all over the place. It doesn't smoke, it doesn't stink, it's not an embarassment to drive! My only real problem now is no tags. That's next.

Thank you so much to all who made suggestions and helped me work through the problems. Yeah!!!!