FE Timing

[jlb169]

We took it out tonight. Set it at 18 deg. Will start when hot. I don't think it's lean if anything it's still rich. Dark side pipes, burning eyes when it's running in the garage. Did notice the tach doing funky things tonight, floating up and down even at idle. One post earlier thought it could be caused by a bad tach. Tell me what you Guys think.

[blykins]

So what about the initial problem? Does it still cut out at higher rpms? If not, then walk around the carb and set the mixtures. Does the engine rpm flunctuate with the tach? Or did the tach just bounce? MSD box?

[Excaliber]

Backfiring at high rpm is something I would associate with a lean condition. Just because your seemingly rich at idle or low speed conditions doesn't mean your not lean at the higher rpms under load. Power valve in the carb would be suspect, IF you have one, not all carbs do. As for the burning eyes, it's a bit of a myth that is always a sign of a rich condition, lean burn can cause the same symptoms. NOX is what you smell and what makes your eyes burn, a LEAN condition generates a LOT of NOX.

As to the black tail pipe, I guess I could fly out there and stick my finger up your tail pipe to verify, on second thought, I'll take your word for it.

[byron w]

Change ignition boxes...........

Byron W

[olddog]

Originally Posted by Excaliber

Backfiring at high rpm is something I would associate with a lean condition. Just because your seemingly rich at idle or low speed conditions doesn't mean your not lean at the higher rpms under load. Power valve in the carb would be suspect, IF you have one, not all carbs do. As for the burning eyes, it's a bit of a myth that is always a sign of a rich condition, lean burn can cause the same symptoms. NOX is what you smell and what makes your eyes burn, a LEAN condition generates a LOT of NOX.

As to the black tail pipe, I guess I could fly out there and stick my finger up your tail pipe to verify, on second thought, I'll take your word for it.

I been following this. I have suspected lean fuel for I while. I think Earny is dead right on this. When you said burning eyes, it told the story.

A lean mixter burns slower, as the fuel molecules are further apart with more air between them. More timing helps to cover up the symptom, by giving the lean charge more time to burn.

So in short, it runs like crap at correct timing because the fuel is not right. Get a wide band on it and you will know for sure, what the AFR is.

[jlb169]

sounds like I've been approach this backward. Thinking I'm too rich, you guys seem to think I'm too lean. Yes it's still backfires through the exhaust at around 3800. I've tried two carbs there's an edelbrock 750 on it now. Had a 4150 holley on it with the same results. thats why I was ruling out fuel.
Excaliber: I agree it wouldn't be worth it for you to check my tail pipe!! Take my word for it. Thanks all!

[Michael C Henry]

Another point is the system with the box gets 12V, and the box supplies the corrected power to the distributer and coil. When operating just the distributor and coil, power usually must be routed through a ballast resister except for starting. GMs use a terminal stud on the starter solenoid and Fords have a terminal on the starter relay (starter resister bypass) power routed to ignition (usually the coil) bypassing the ballast resister while cranking. on systems not using the box, Not using the ballast resister can cause some coils to overheat and be permamently damaged.

[jlb169]

Mike I'm sorry I don't understand what your trying to tell me. I do have a ballast resister in the wiring. Are you saying I'm wired wrong?

[Michael C Henry]

Keep in mind what you did and how it ran. I'm using my arangment as my baseline. with theMallory box in use it gets full 12V if you bypass the box and user only coil and distributer that gets ressisted power( less than 12V. If you are using yhe box bypass the resister and use full 12V. If you are bypassing the box use the resister. If you used full voltage and were just using coil and distributer for extended times, you may have damaged the coil. afterwards it't hard to remember what was in place when but try to remember. When this symtem hit me it turned out to be my new Mallory HyFire 6AL box. Try to keep your kool and keep track of what you have and are trying and what changed or how it ran. for later assesment.