timing setting for high altitude?
timing setting for high altitude?
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Joined: Jan 2001
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From: Virginia
Never heard of a special timing setting(though I definitely don't know everything). The problem is the fuel and the carb. You will find the engine running rich and blowing black smoke because there is not as much air up high. Carb re-jetting is the most common modification.
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Joined: Nov 2007
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From: Denver Metro Area, CO
I'm at 5300 down in the city and try for about 15-16 BTDC on my 1981 400 (no computer
controls).
Franklin is also right about the jets, Holley suggests go down one size for every 2,000 feet
in elevation. On my Truck Avenger (came out of the box set up for sea level) I reduced the
primary jets by 3 sizes, the plugs show it running a bit lean so I'll up the size by one later
this week (it seems you have to go to a speed shop anymore to get carb parts, consumer-
oriented auto parts places don't have stuff like that in stock anymore).
controls).
Franklin is also right about the jets, Holley suggests go down one size for every 2,000 feet
in elevation. On my Truck Avenger (came out of the box set up for sea level) I reduced the
primary jets by 3 sizes, the plugs show it running a bit lean so I'll up the size by one later
this week (it seems you have to go to a speed shop anymore to get carb parts, consumer-
oriented auto parts places don't have stuff like that in stock anymore).
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The Ford dealer locally recommended 12 degrees BTDC.
Porblem now is: I am having one hell of a time getting to the Dampner and degree marker to clean it off little lone marking it with chalk or paint. There is so much stuff in the way. Is it best to try and look from the top looking over the center of the radiator and down into the engine or how? Then how is one supposed to read the marks???
We tried for over 3 hours to see the plate with degree markings and when we cleaned it off I still could not see and graduation lines.
What am I doing wrong?
Porblem now is: I am having one hell of a time getting to the Dampner and degree marker to clean it off little lone marking it with chalk or paint. There is so much stuff in the way. Is it best to try and look from the top looking over the center of the radiator and down into the engine or how? Then how is one supposed to read the marks???
We tried for over 3 hours to see the plate with degree markings and when we cleaned it off I still could not see and graduation lines.
What am I doing wrong?
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Joined: Dec 2007
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best way i have found is to lay under the truck looking up at the crankshaft pully then rotate the engine with a breaker bar and a deep well socket like 15/16 if i remember right. You should be able to see them pretty easy there. good luck
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Joined: Nov 2007
Posts: 22,415
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From: Denver Metro Area, CO
fordmanjoe has a good suggestion for marking the thing - crawl under there, clean it and
mark it. A remote starter switch is helpful, too, if you have one.
When you try timing it, line up the marks along the long, flat edge of the indicator, not the
pointed end. I painted y indicator yellow, harmonic balancer is black and I painted 3 lines on
it... a solid white one at 0, a dashed white one at 10, a solid orange one at 15.
Yes, it's a pain to find the marks with a timing light; I don't have a smog pump so it's a bit
easier to peer down by the water pump from the top, a friend showed me how you can
sometimes look through the fan from the front.
12 BTDC may be fine for you, it definitely shouldn't ping there. If I were you, I'd try at 15
and see if the engine pings while warmed up and under load; if it does, back it off a bit and
try again; if it doesn't, leave it at that and call it good.
mark it. A remote starter switch is helpful, too, if you have one.
When you try timing it, line up the marks along the long, flat edge of the indicator, not the
pointed end. I painted y indicator yellow, harmonic balancer is black and I painted 3 lines on
it... a solid white one at 0, a dashed white one at 10, a solid orange one at 15.
Yes, it's a pain to find the marks with a timing light; I don't have a smog pump so it's a bit
easier to peer down by the water pump from the top, a friend showed me how you can
sometimes look through the fan from the front.
12 BTDC may be fine for you, it definitely shouldn't ping there. If I were you, I'd try at 15
and see if the engine pings while warmed up and under load; if it does, back it off a bit and
try again; if it doesn't, leave it at that and call it good.
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We tried for over 3 hours to see the plate with degree markings and when we cleaned it off I still could not see and graduation lines.
What am I doing wrong?
What am I doing wrong?
My eyes are not great and there was not much left of the markings so I held a digital camera with a flash up close and got a really good picture of mine. I dont know whats left of your markings, but it made what was left of mine stand out very clearly.
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