Thread: Timing and Plug gap for my 390FE

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I just had my FE 360 turned into a 390. I am having timing issues with it. It is driving me crazy. I have 8.9:1 compression ratio with 180 lbs per cylinder. A comp cam #252. 4bbl holley truck avenger 670 cfm carb and a Edelbrock performer 390 intake. All components like alt,p/s,distributor(stock electronic reman) etc. I cant get the timing curve right and don't know where the plug gap should be set. (.035 for earlier w/points or 42-46 w/electronic ignition)??? Or maybe a mix??? I have the earlier timing set. It is in my 76 Ford F-250 High Boy with stock electronic ignition. Is this ignition set up my problem with timing or what? HELP PLEASE!

Thanks

i'm not sure if i'm right with this but i use a "petrotonix ignitor" for my ignition instead of points and it works great that might be your problem and by the way the performer intake manifold is the stock one for the 390 except it is alluminum the performer rpm manifold is the upgrade (didn't know if you knew that or not i was looking at them and saw that and was surprised) and also that is a really really sick sick truck!!!! my god i wish i owned that

Ksbsn88 , I do have the stock electronic ignition on this truck and not points. Ford changed this I guess in 75. The stock gap for this system was .042-.046 but this was for the emmisions bull that was originally on the engine. From 60's to 72 or 74 there wasn't the emmision crap the 390's were points and the gap was .035. The 390 here is a pre 74 build. So I am wondering if I need a MSD ignition sys. or if the gap is the problem cause I don't understand what the gap does anyway. I am set at .040 right now. I cant adjust the vaccume curve any lower so I have it disconnected. It was topping @ 51 deg and pinging. I am just using mechanical curve now w/a 20 degree throw, idle set at 14 deg BTC with a top end throw @ 35 degrees. It seems to run ok there but it would be nice to have some vac throw at idle take off. What is a patrotonix igniter? where do you get them?

Thanks
Scott Jensen
Orig. Owner

If you have access to a timing light with a advance dial or degree tape for the balancer I recommend the following: dissassemble the distributer and weld the advance pin slots a little at a time untill you get aprox. 20 degrees advance in the distributer (vac advance disconnected). Put a combination of springs on to get the advance to start at about 12 degrees and all be in by about 2500 - 3000 degrees. With about 10 degrees initial you will get about 30 degrees all together with the vac advance disconnected. If you get hard throttle ping, back off the initial a little at a time until the ping is gone. There is a allen head adjusting screw inside the vac nipple on the vac advance on most fords. Turn the screw Clock wise until it pings at part throttle then back it off until it dosen't. Turn the screw counter clockwise if it pings to start with. The vac advance is out of the picture at full throttle. Its only there for cruise economy and part throttle drivability.

Best of luck.

http://www.pertronix.com/ and find the ignitor or ignitor 2 it works for me but it prob. won't solve all of those pinging problems