1966 427/425 Horsepower

[Jerry A.]

My 66 425 horse car was totally restored in 2000. Original engine completly rebuilt. The car is rarley driven and trailered to shows (mainly due to dirt roads we live on). I believe I replaced the plugs with 45N's to somewhat preclude plug fouling. We took the car out for a few drives lately, including the expressway. I am getting semi-continuous backfiring from the exhaust. Sounds like both sidepipes. It idles great and feels strong. Any help will be greatly appreciated.

Thanks, Jerry

[Clem Z.]

Re: 1966 427/425 Horsepower

if it back fires thru the pipes when you let off the gas i would check for exhaust leaks. air getting into the exhaust system will cause this problem either from leaks or if you have a "smog pump" from a bad diverter valve

[Jerry A.]

Re: 1966 427/425 Horsepower

Thanks Clem,
I don't think it happens when I deaccelerate but when normal driving. Will check side exhaust at manifold because I do know that it does get loose. What about when it does it during acceleration?

Jerry

[Clem Z.]

Re: 1966 427/425 Horsepower

if it does it during acceration i would guess it is ignition related. i like R 45XLS plugs because the extended tip plugs stay cleaner at around town driving. if you have TI make sure you have a bright blue/white spark that will jump 3/8" to 1/2" when checked to ground or might have a weak TI coil. i just tested a couple last week and i found one was weak and would not jump the gap on my coil/amplifier tester.

[William C.]

Re: 1966 427/425 Horsepower *NM*

[Jerry A.]

Re: 1966 427/425 Horsepower

Thanks Clem,
Will check it out!

Jerrty

[Bill Stephenson]

Re: 1966 427/425 Horsepower

Jerry,

------Clem always seems to have good advice.Also,check that your coil to distributor wire isnt grounding out against the radio shielding.It can cause this type of problem.I know from experience.............Bill S

[Jerry A.]

Re: 1966 427/425 Horsepower

Thanks alot Bill, will check it out.

[Clem Z.]

hey bill would you please e mail my wife

your first statement.

[Bill Stephenson]

Re: 1966 427/425 Horsepower

------Always here to help,Clem!........Bill S