[pacificnwrider]

So I just completed a frame swap project on my 65 vert, and last night, for the first time in a year, I took her for a spin, how I missed "top down warm summer night" driving! but am grateful for the opportunity to cruise a little yet this summer. Anyway, during the ride, the car had a very slight surge at cruising speeds. It was almost imperceptable, and it took about 20 minutes of driving before I convinced myself it was actually there. Its got an updated electronic ignition, no points, new, plugs and wires, cap and rotor. The carb will need a rebuild too. I'm wondering if this could be the vacuum advance not functioning properly? The distributor is out of my old engine, and the old engine didn't have this problem. If you've had this happen to you or any ideas what it could be I'd love to hear from you. THANKS!

 

[KULTULZ]

I would suspect a bad/wrong power valve.

 

[pacificnwrider]

I would suspect a bad/wrong power valve.

Thanks for your reply! forgive my ignorance, but what's a "power valve" intake? exhaust valve? It has a wicked knock at the moment, I'm going to pull the valve covers off, I suspect it's a rocker arm or a collapsed lifter. Its not a rod or main knock.

 

[KULTULZ]

Power valve

For open throttle operation a richer mixture will produce more power, prevent pre-ignition detonation, and keep the engine cooler. This is usually addressed with a spring-loaded "power valve", which is held shut by engine vacuum. As the throttle opens up, the vacuum decreases and the spring opens the valve to let more fuel into the main circuit.

-Above plagiarized from Wiki


The power valve is in the carb and gives more fuel as needed. It opens with less manifold vacuum and is calibrated to a certain manifold vacuum rating. It may be that yours is opening/closing at a cruising speed manifold vacuum causing surging as fuel is cut in and out.


Do you have an AUOTLITE 4100 carb?



Also- FE's That Bend Push-rods, A Dirty little Secret .: Articles

 

[PSIG]

You mention the carb needs a rebuild. I would start there. While the vac advance and power valve can be responsible, the vast majority of cars with lean surge (hunting) are simply a tad lean. This is becoming very common as the fuel additives such as ethanol are becoming higher in percentage. Most stock classic Fords I see are either rich (wear, damage or mis-adjustment) or lean (other wear, dirt/buildup, mis-adjustment or oxygenated fuels) and almost never 'right'.

David

 

[pacificnwrider]

Here's an update: so I had the valve covers off today and inspected all the components. push rods, rocker arms, and associated components look functional. I'm not sure the type of carb i've got, but it's the factory 4bbl. Autolite 4100? its bone stock...is this a good carb or should I abandon it in favor of a holley or other aftermarket replacement?
Really dissapointed and discouraged tonight, had an engine fire, and while I caught it almost immediately it still toasted the paint in the engine compartment and the paint on the hood...ugh!

 

[PSIG]

Here's an update: so I had the valve covers off today and inspected all the components. push rods, rocker arms, and associated components look functional.

Your inspection needs to include rotating the crank with a ratchet on the crank bolt every 90° starting at TDC. This will allow you to check each pushrod by spinning it between your fingers to verify straightness and also looseness (relative to others). At TDC you will be on firing stroke of either #1 or #6 cylinder and you'll start with the one that has both valves fully closed. Inspect that cylinder, then turn the crank 90° clockwise and check the next cylinder in firing order (1-5-4-2-6-3-7-8). If you want to do a thorough job, you'll mount a dial indicator and verify the lift of each lifter body to rule-out cam lobe damage.

I'm not sure the type of carb i've got, but it's the factory 4bbl. Autolite 4100? its bone stock...is this a good carb or should I abandon it in favor of a holley or other aftermarket replacement?
Really dissapointed and discouraged tonight, had an engine fire, and while I caught it almost immediately it still toasted the paint in the engine compartment and the paint on the hood...ugh!

Ack! Obviously things need attention. Anything that fits an FE is a decent carb. Most like the 4100 best for it's performance, easy maintenance and brick reliability, but whatever you have can be made to work well. The up-side to original carbs is they don't require extensive tuning to work perfectly in all conditions like a replacement would.

David

 

[puttster]

Really dissapointed and discouraged tonight, had an engine fire!

Yeoww, a fire is a bummer.
But at least it should give you a clue about what's causing the surging. Plus no need to rush into repainting the hood, look for alternatives...

 

[pacificnwrider]

Yeoww, a fire is a bummer.
But at least it should give you a clue about what's causing the surging. Plus no need to rush into repainting the hood, look for alternatives...

Ya know, I never tire of pictures of galaxies! that one is inspiring!

I entirely agree David, it needs attention. Just FYI, here's some of the history of me and this car(s) In 2007 I bought this sight unseen in Puyallup, WA,(about 180 miles from my home in eastern Washington) went over, filled the master cylinder, threw a towel over the copious amounts of bird crap(been stored top down a few years in a barn) checked fluids, fueled, and drove it home...(crazy I know)
I spent the next week or so doing some obsessive tinkering and was able to take it in the labor day parade in my home town with my kids in back. I proceeded to drive it after that tinkering and fixing here and there, but more or less trouble free until last September. While I've never been dissapointed in my "sight unseen" purchase; when inspecting the car in the weeks and months after I bought it, I realized the frame was going to need replacement due to RUST...AHHHHH! yes rust...ugh the black plague of all old wheel turning iron.
Back to last September; being continually plagued by the knowledge this was a safety issue, I started prepping myself for a frame replacement. I found a desert 1966 sedan with a very sound frame. I stripped the body off this chassis, and between September and now, I’ve been in the process of putting the 65 vert body on the 66 sedan chassis. I did the swap with the chassis untouched, engine, transmission, drivetrain, and so on. Simply removed one body, and re-set another.
I’d driven the 66 around a bit before the swap, just to make sure the engine and trans were sound, and I was satisfied they would be. The valve knock didn’t manifest itself until after the swap was complete and I did the run in with the vert body on that chassis, ugh!
My hopeful future plans for this include rebuilding the original 352 and Cruise-O-Matic and replacing it. I hope to make this engine a good cruiser through the end of summer 2013.
Whew, I guess that’s the long version, but there ya go.

 

[pacificnwrider]

As a post script for that long post(sorry) any tips on adjusting the mixture on the Autolite 4100? where are the adjustment screws? The one I'm most familiar with is the 2bbl motorcraft

 

[pacificnwrider]

Yeoww, a fire is a bummer.
But at least it should give you a clue about what's causing the surging. Plus no need to rush into repainting the hood, look for alternatives...

btw Puttster, you sold me on that, is that a decal? screen print? or paint? no matter what it is...yowza! looks awesome!

 

[KULTULZ]

...where are the adjustment screws?

See Attached-

 

[puttster]

btw Puttster, you sold me on that, is that a decal? screen print? or paint? no matter what it is...yowza! looks awesome!

When my hood got scratched up I took the opportunity to upgrade with some art. I had a book of Luis Royo's works so I brought it down to a graphics place and had them one of the pages. I told FEand GoingBroke it was a pic of my wife getting ready for bed, which upset him. If he would have given me a megapixel file pic of his smokin hot wife I could have used that instead.

The graphics place makes a 3M vinyl stick-on with 5 year guarantee. If you change your mind it will peel off. They can give you a sample before going final - the bigger the picture or the denser the digital you give them the sharper the final product will be. Retail was $450 installed but I had an intoductory 25% off at A&E graphics in Houston. Their machine could not do the whole hood in one pass so there is a seam down the center. The vinyl will not cover imperfections, see where I tried to cover the uneveness to the right side of the girl? Still, I cannot go to a gas station without someone coming over and admiring the art. It is a lot of fun, best investment I have made in this car!

 

[rambuttt]

Surging at cruise will almost certainly NOT be fixed by adjusting the idle screws...all that'll do is goof up the idle and/or mask the real problem. The "leaner" new-age fuels usually require an increase in jet sizes...in this case, I would try 1 or 2 sizes bigger in both the primary side and the secondary side. Also, the power valve is not really a very likely source of the problem, IMHO, BUT, those rubber babies don't like the new fuels very well so changing the P/V out is a good idea as long as you have the carb opened up/removed from the engine.

 

[PSIG]

Surging at cruise will almost certainly NOT be fixed by adjusting the idle screws...all that'll do is goof up the idle and/or mask the real problem. The "leaner" new-age fuels usually require an increase in jet sizes...in this case, I would try 1 or 2 sizes bigger in both the primary side and the secondary side. Also, the power valve is not really a very likely source of the problem, IMHO, BUT, those rubber babies don't like the new fuels very well so changing the P/V out is a good idea as long as you have the carb opened up/removed from the engine.

+1 to all that. Rebuild it and then tune it back in as necessary. The factory manual or books specific to your model carb are helpful.
:tup:
David

 

[pacificnwrider]

Thanks for all the great information guys! I swapped carbs from a runner I had on the decomissioned 352, and the surging is gone. I've bought a kit and will do the rebuild when the weather gets crappy...for now I want to be able to do a little top down driving while the weather is good. Also, I posted a couple pics of it in the pics forum. thanks again guys!

 

[PSIG]

... I've bought a kit and will do the rebuild when the weather gets crappy...

Cool. Drive while the driving's good!
:tup:
David

 

[ShotRod64]

The 4100 is super easy to rebuild. I ended up getting the kit from autozone as napa doesn't include the rear accelerator pump thing and a couple other things that have to be bought seperate. Get some carb cleaner or a can of cleaner if it's real nasty to let it soak in for a bit and then get to putting it back together. I love the 4100 because other than the air/fuel mixture the floats get adjusted when rebuilding and you're ready to roll. Great for the person like me who likes "plug n play" not tinker, swap, adjust this and that stuff.

Might check for vacuum leaks also just in case.