Timing advance
Thread Starter
|
New User
Joined: Nov 2011
Posts: 3
Likes: 0
From: Brooksville Ky
Timing advance
I have a 1991 E150 5.0 auto , the van runs very good but when I'm pulling steep grades it just don't seem to have the power it should have ,let me say it has an airplane gear probably a 3:08 or something like that but still I think it should do better than it does , other than that I have no complaints !Ive been reading the Haynes Manual and I might be misunderstanding the book but if I'm reading it right I can't just loosen the distributor and advance the timing a few degrees to see if this would give me a little more power because the computer or something to do with the distributor would over ride my turning of the distributor or am I wrong and can advance it a few degrees ? any advice to get the most power out of this 5.0 would be helpful like what would be the best setting by a light ? Thanks for any advice ,all yeh near future plans I am going to have a 3.73 gear installed I believe in this hill country I live in would probably help my gas milage because I wouldn't be straining the vehicle and it would not be shifting in and out of OD all the time.
Junior User
Joined: Oct 2012
Posts: 54
Likes: 0
Worth a try advancing the timing a little. More advanced means higher engine temps where the hills might amplify the temp.
The vans manual findable online has a section showing where to find the coded listing of your installed rear axle and other data on a vehicle sticker. A 90's manual shows the 5.0 with 3.31 rear ends.
The vans manual findable online has a section showing where to find the coded listing of your installed rear axle and other data on a vehicle sticker. A 90's manual shows the 5.0 with 3.31 rear ends.
Postmaster
Joined: Feb 2011
Posts: 3,560
Likes: 1
as for the optimal timing, it depends on engine condition, altitude, and fuel quality. usually the factory settings are a bit low, but are just about guaranteed to be safe. feel free to turn it up a little, then start driving up a hard hill and listen for any pinging noise. any such noise means you turned it up too far. you'll probably find yourself playing with it back and forth for an hour to find your optimal setting without going too far. when i do it, i run hard for a couple of miles, pull off the road in a wide spot, adjust, and repeat. but i have a country road with a place to stop every mile or so, so that works for me
Junior User
Joined: Oct 2012
Posts: 54
Likes: 0
Easy method to remember is your going advanced timing on ignition runs the spark more and more before top dead center (TDC). Firing the spark more and more advanced ignites the gas before TDC leaving the combusting gas (HOT) to be compressed even more during compression before TDC. Hence there is extra heat being put to the cyclinders during compression. But you get a fuller expansion stroke.
Now when timing is retarded it fires after TDC not adding any type of heat like advanced would. You can figure you even get a little cooling from the compressed fuel vapors during compression. Then it fires off retarded which is during the expansion stroke just before the exhaust stroke.
Advanced timing is hotter. Too far advanced is fighting the engines cycle. You might figure advanced timing can allow the spark to fire things up so that during faster rpms the combusting gas is fully igniting by time the rotation gets TDC for the cylinder.
Now when you play retard and advance the cam you are moving the best power up and down the rpm range. Guess which way the power moves on the rpm curve retarding. Yah its opposite what you naturally think with the terms used.
Now when timing is retarded it fires after TDC not adding any type of heat like advanced would. You can figure you even get a little cooling from the compressed fuel vapors during compression. Then it fires off retarded which is during the expansion stroke just before the exhaust stroke.
Advanced timing is hotter. Too far advanced is fighting the engines cycle. You might figure advanced timing can allow the spark to fire things up so that during faster rpms the combusting gas is fully igniting by time the rotation gets TDC for the cylinder.
Now when you play retard and advance the cam you are moving the best power up and down the rpm range. Guess which way the power moves on the rpm curve retarding. Yah its opposite what you naturally think with the terms used.
Postmaster
Joined: Feb 2011
Posts: 3,560
Likes: 1
with all due respect here, i think we disagree on this one. personal experience shows that retarded timing can produce an exhaust manifold glowing cherry red. thats a lot of energy wasted as heat.
ALL the energy of the fuel will be released when it burns, and timing decides how much of that will be put into moving the piston down vs heat. more advance means more of the fuel being used to move the piston, and less thrown off as heat. less advance (retardation) means more of the energy being thrown off as heat and less moving the vehicle down the road
ALL the energy of the fuel will be released when it burns, and timing decides how much of that will be put into moving the piston down vs heat. more advance means more of the fuel being used to move the piston, and less thrown off as heat. less advance (retardation) means more of the energy being thrown off as heat and less moving the vehicle down the road
Thread
Thread Starter
Forum
Replies
Last Post
Thedonk
1987 - 1996 F150 & Larger F-Series Trucks
7
Aug 21, 2016 12:57 PM
BrownBadger
1967 - 1972 F-100 & Larger F-Series Trucks
5
Mar 25, 2015 10:36 PM
RocketmanVT
1987 - 1996 F150 & Larger F-Series Trucks
10
Dec 30, 2012 05:04 PM
MauserRob
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
15
Jul 27, 2005 08:00 PM
