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#1
05-09-2009, 03:29 AM
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timing question/help
wondering what u guys recommend for initial timing for me..i run a msd pro billit dist with no advance hooked up...(very low vacuam)..
engine is 428 with 260 cfm sd heads, hooker comp headers, 3in exhaust carb is 850 db wo/choke tower. 2.5 pv 30 cc front pump and 50 cc rear. cam is comp solid roller... 260/268 dur @ .50 108 lob sep.and 650 lift with 1.5 roller rockers (lift calculated w/rockers) aprox 10.5 compression but im at about 5500ft altitude. 3.42 gear with 28in tire. ] car weighs 3500 with me in it. working towards gettin it on the track but sees street time also.
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69 bird, 428 custom solid roller, rpm intake, #62 heads sd ported 260 cfm, 850 holley dp. arias pistons.scat rods redneck tranny, continental 3200 stall |
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#2
05-09-2009, 04:18 AM
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Try this
How much wide open/max RPM timing do you/can you run on this engine at 5500 ft.?
How much mechanical advance does this 'msd pro billit dist' have? Answer those questions and base timing will be.....................right there. Base will be a product of what's left over. And wont be much you can do about it, without changing the amount of mechanical advance in the distributor. FWIW Sometime in the past, I've run limited advance distributors. And what it took to run wide open made cranking nearly impossible. One more FWIW, base timing for hopped up engines isn't like looking it up in a book for a factory stocker. |
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#3
05-09-2009, 02:10 PM
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im gonna have to pop the cap off and see what springs i put in there..its been to long for me to remember..but as far as initial advance....im talking about where i set the distributor...i run a small jegs starter and really seems i can pretty much set my timing any where i want and still crank fine.
but i dont want to run so much that im hurting the engine or my top end.. i'll have to recheck but it seems like im running quite a bit of base line timeing...ie. maybe 14-16 degrees and i was thinking that was alot but then it hit me that im not running any vacuum advance so i thought, well maybe that isnt so much?...
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69 bird, 428 custom solid roller, rpm intake, #62 heads sd ported 260 cfm, 850 holley dp. arias pistons.scat rods redneck tranny, continental 3200 stall |
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#4
05-09-2009, 03:21 PM
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Back 37 years ago living in Clovis N.M. at 4400 ft. above sea lavel I was told by Red Nevins,a popular Pontiac racer in his day, to add 1 degree for every 1000 ft. I ran 40 -42 with the premium gas of that time. I guess 38 to 40 would be ok with todays gas at 5500 ft.
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#5
05-09-2009, 03:49 PM
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well i just checked.....im running what looks like 38-40 on total and it seems to come in pretty quick...cant tell for sure cuz i cant see tach but the R's dont sound that high.
as far as idle im at about 14....idling at about 850 car starts up fine and shuts off with out run on. adjusted idle screws and got vacuum up to about 5-6
__________________
69 bird, 428 custom solid roller, rpm intake, #62 heads sd ported 260 cfm, 850 holley dp. arias pistons.scat rods redneck tranny, continental 3200 stall |
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