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Hey Folks,
I have a question about my 68 Ford Galaxie. It has a 390 and originally had a 2 barrel carb. I went to a 4 barrel Hollycarb and an edlebrock performer intake. My main problem is with timing I think. Does anybody know what the total advance should be for this car? my mechanical is set for 36 degrees.
Also Im wondering if headers would make any performance improvements?
Thanks very much in advance
Headers will help some with the performance.. Where is it pinging at in the RPM's and what fuel are you running in it? 36 is probably plenty high for an FE engine, might want to back it off to 34 degrees.. If it is pinging at low RPM, you might be bringing the advance in too soon.....
Denny, does your book say what the intial timing with the vacuum advance disconnected at idle should be? My memory keeps coming up with 8-10 degrees, but my memory sucks!!!!!!:LOL: :LOL:
The problem may also lie in the fact that your 390 was built in 1967, when there was plenty of high-quality fuel to be had for cheap. The stock compression ratio is probably too high to use available pump gas with an iron-headed motor in my opinion. There is also the question of squish, or should I say lack of it. I'll bet the piston to head clearance on that motor is 0.080" to 0.100" or maybe more. If it were more like 0.035" to 0.040", you might get by with pump gas.Quote:
Originally Posted by artymac
Hey fellas,
Thanks for all the answers . Now let me fill ya in on the rest of the story.
I did install an advance curve kit(lighter springs). So I know that my advance is coming in sooner. before putting in the curve kit I read this article on ford distributors - http://www.bob2000.com/dist.htm
it talks about the limiter plate that you can flipflop in order to change your mechanical advance. What I'm not sure of is if the store gave me the right distributor. on my limiter it is scribed with 18L and 21L. I have it on 18L which in theory gives me 36 degrees of mechanical- that being said, with my initial at 6 BTDC I'm at 42 degrees total and pinging like hell(starts at 200 RPM).
I back it down and the pinging does'nt stop until my intial is at TDC. I'm considering a new distributor for better performance but doesnt break my wallet. any ideas for my problem as well as advice on an aftermarket distributor would be Greatly appreciated.
Thanks Again
- Mac
I meant starts at 2000 RPMs !
way too much advance!!! Look at Denny's chart on what the motor needs for mechanical and vacuum advance... Real good info there
I am having the same problem with a 66 390 that was originally a 2 bbl that has been changed to a 4 bbl,I have been trying to ween it off premium but even being a 2 bbl motor the compression is close to 10 to 1 so it looks like premium will have to be used. I added electronic ignition and have been playing with the jets in the carb and I think it will run on 89 octane decently but I noticed it pinging a little too much with 87 when its warm outside,it did not ping on the return trip when the temp cooled off some so I am thinking about making a dual snorkel aircleaner with hoses going to the core support to get cooler air in the motor. Jeff
Might have to run some octane booster, Jeff..... that's a lot of compression for the stuff that comes out of the gas hose these days...
Well I finally have made some progress. The main point was that, with the old distributor the leas t amount of Centrifugal advance was 36 degrees- thus the only place I could have my initial set was like TDC/ 0 degrees to not ehar a ping.
I bought a new reman. distributor and as luck has it. this one has a 13L plate for 26 degrees of centrifugal. Yeahhh!
Doing Much better now but I know that she can still give me more!!!
How do you find the total advance as I would like to check it on my 390. Jeff
Hey Jeff,
The answer is pretty easy...
Teh "Total Advance" is the sum(additive) of the your intial timing-
ex. for a 390 is 6BTDC take that plus your total amount of centrifugal advance. - The maximum you can get from your distributor.
ex. 6 degrees BTDC + 26 degrees centrifugal = 32 degrees total advance.
check out this article:
http://www.fordmuscle.com/archives/2...ng/index.shtml
very helpful!!
- mac