Slick 60's

I have had some bigs ups and downs with this 460. First I thought there was a problem when i found water in the oil but I changed the oil and it is fine now. The engine also never idled correctly since I bought it. I found a vacuum leak and it ran pretty good after that. I got the engine to idle and run good for around 15 minutes. It was running open headers so i figured since its running so good that i would put an exhaust system on. I put the exhaust system on and installed new exhaust manifold gaskets. I went to start it up and now its hard to keep it running at idle and backfires through the exhaust and carb. I figured it was a problem with the carburetor since I had a cheap $20 Quadra jet on it. So today I went out and bought a new Edelbrock carburetor and am having the same problems. I also triple checked the firing order. The spark plugs I took off were all black with carbon too. If you guys could help me out with this I would greatly appreciate it as this is getting frustrating. Tomorrow I will get a video up and see if that will help. Thanks a lot and sorry for the huge posting.

Check the firing order one more time. If it ran well before the exhaust work then crossed or damaged spark plug wires are at the top of the list. Quadrajet on a ford is that even legal!!
Tech

carbon fouled plugs from running too rich a mixture.

you did not mention if you have points or electronic type ignition, if points check the gap/dwell.

It is electronic ignition and yeah I know about the quadra jet but I just wanted to get something on there, don't worry its not going to be on any more fords of mine.

Backfiring through the exhaust and carb, and idle problems, sounds like it might be due to improper valve adjustments. A vacuum leak could also cause those symptoms. But...that would have been the case before exhaust was installed also. Tech's suggestion of checking the plug wiring is spot on, especially if you removed the wires when you replaced the exhaust gaskets. Did any spark plugs get damaged replacing the gaskets?
I would begin troubleshooting by performing a compression test. If all checks out, double check the ignition and carb. I have had problems with 460 intake gaskets sealing, when using the "dishpan" type gasket.

Roger Carter

The backfire through the carb does suggest a vacuum leak. A little anti freeze in the oil might point to the intake manifold gaskets. I would at least re-torque the intake manifold bolts and see if that doesn't help some of the problem.

Well I got the video up hopefully you guys might be able to see whats going on. http://www.youtube.com/watch?v=ihMdQcNZTXA

It seems like its gotta be something with the timing but I keep on checking that hoping it will be the problem but its not. I will have to try some of the things you guys suggest today and make sure all the plugs are firing and in good order. I already double checked for vacuum leaks because it seems like that could be the problem too. Thanks for the help

hey i think i found the problem. I sprayed some starter fluid around the driver side intake gasket and it was sucking the fluid up and reving up while i was doing that. So I will change that and hopefully that will do it. Thanks!

Here are some pics to show whats going on.

Some people use a small propane torch (unlit of course ) to check for vacuum leaks / intake manifold gaskets too. I'd forgotten that little trick.

make sure you check the gasket to the ports on the head and intake before you install it.

Looks like a 429 CJ intake on regular 429/460 heads. It is a more common mistake than you would expect. Hawkrod

with Hawkrod time for a new intake that matches

Hawkrod wrote:Looks like a 429 CJ intake on regular 429/460 heads. It is a more common mistake than you would expect. Hawkrod

I agree, too. Looking at the relationship of the top front intake bolt to the number 5 port pretty well confirms that.
All is not lost though. Use a set of Cobra Jet intake gaskets with your intake and it should seal to the non CJ heads.
Not an ideal fix, but workable. In fact, Ford recimmended doing just that in their late 60's "Muscle Parts" books. They said that in spite of the port mis-match, the the Ford CJ intake was worth over 10 horespower compared to a stock (non CJ) intake, when bolted to a set of stock, non-CJ heads.

Roger Carter

Roger Carter wrote:

Hawkrod wrote:Looks like a 429 CJ intake on regular 429/460 heads. It is a more common mistake than you would expect. Hawkrod

I agree, too. Looking at the relationship of the top front intake bolt to the number 5 port pretty well confirms that.
All is not lost though. Use a set of Cobra Jet intake gaskets with your intake and it should seal to the non CJ heads.
Not an ideal fix, but workable. In fact, Ford recimmended doing just that in their late 60's "Muscle Parts" books. They said that in spite of the port mis-match, the the Ford CJ intake was worth over 10 horespower compared to a stock (non CJ) intake, when bolted to a set of stock, non-CJ heads.

Roger Carter

Yup, the CJ intake will work well (but a port matched aftermarket intake would likely be better) but the mistake is not using the CJ gaskets when using the CJ intake. Hawkrod

Yep I talked to some guys at 460ford too and they said the same thing. I ordered CJ gaskets yesterday and will put them on as soon as I get them. I hope this solves this because I wanted to get a video with the cherry bombs on. Thanks for all of the help.

while you have it apart, replace your head gaskets, especially since you found coolant in your oil.
It is worth the extra time and money to do it now. I didn't and found I had a pin hole leak in my head gasket ...now I have to tear it all back down again after having to rebuild my radiator not a cheap fix!!!