making my own active feul management like chevy

[kanoshee]

we're also not real sure where this engine came from if it's original but it's got the two pipe intake system from the ninety's and that big aluminum intake manifold that 5.0 in that goofy font. right now this truck gets 10 mpg if we're lucky, i'm pretty sure something is wrong lol she does click and clatter something's up with my valves and if we have to mess with them anyway i'm trying to design some sort of valve cut off but i don't have a machine shop so i have no idea how I could do it

[c_silva88]

the 4.9 i the straight six. there is 2 ways to determine if the trucks a wide or close that i know of . if the transmissions still in the truck you open the drivers side door and look at the tag in the door jam there is a column that says transmission if there is a c under it it the close and if theres a w then its a wide ratio. and the other works if you were to have found a transmission already out: first shift the transmission in to first and mark both the input and out shafts and turn the input(side that mounts to the motor) keeping count how many turns it takes before the output completes one complete revolution. im sure there is some way to decode the tags on the transmission it self but i've always used the 2 methods i mentioned above.
your 10 mpg could be coming from the fact you don't have any o2 sensors for the computer to use to maintain a good air/fuel ratio with out them the computer would go into limp mode. how dose the truck run? dose it smell as if its running rich?

[2000neon]

Originally Posted by kanoshee

it doesn't have o2 sensors and thanks which would be better not compressing in the first place or the compression/down pressure?

I couldn't tell you to be honest. Although I would guess that having the valves closed would be better, since to have no compression, both valves would be open, and so the piston would still be pumping a whole lot of air, which I think would lower efficiency by quite a bit.

Also, I wouldn't suggest swapping an inline 6 for the V8, a buddy of mine has had a pile of these trucks, with both motors, and he has consistently found that the V8's actually have better mileage, until you start driving it hard. Especially for you pulling stumps and really using the truck, the V8 is most likely the better all around engine.

He usually averaged about 15 MPG, but his is 2WD. How is your truck mechanically? Plugs, wires, cap, timing, fuel filter, etc.?

[kanoshee]

Originally Posted by c_silva88

the 4.9 i the straight six.. how dose the truck run? dose it smell as if its running rich?

i think it's running lean at idle but good at high rpms. and did they have o2 sensors in 85? i'm not sure if this truck was pieced together or if it was converted to fuel injected or special ordered or what?. i'm thinking it was converted well a good while ago. and now it just ain't quite right. i don't think it has a cat either. but the valves do tap pretty bad. we've been using it too much to tear it down any. low range rpms run pretty bad. ESSPECIALLY under load i'm starting to think we just need to go get an l-6 but like i say before i put too much money into i'de buy a 2wd highway truck.

[c_silva88]

Originally Posted by kanoshee

i think it's running lean at idle but good at high rpms. and did they have o2 sensors in 85? i'm not sure if this truck was pieced together or if it was converted to fuel injected or special ordered or what?. i'm thinking it was converted well a good while ago. and now it just ain't quite right. i don't think it has a cat either. but the valves do tap pretty bad. we've been using it too much to tear it down any. low range rpms run pretty bad. ESSPECIALLY under load i'm starting to think we just need to go get an l-6 but like i say before i put too much money into i'de buy a 2wd highway truck.

my 84 has a computer controlled carb which uses an o2 sensor to adjust the air/fuel mixture. and even with the computer controlled stuff acting up ( runs extremely rich)i can consistently get 18mpg out of the 4.9. now swapping a 4.9 in place of your 5.0 is straight forward you can use you current wiring and transmission i can walk through the swap as far in what you'll need and what to do wiring wise, i've done a couple.and complete motors can be had for cheap.

Originally Posted by 2000neon

I couldn't tell you to be honest. Although I would guess that having the valves closed would be better, since to have no compression, both valves would be open, and so the piston would still be pumping a whole lot of air, which I think would lower efficiency by quite a bit.

Also, I wouldn't suggest swapping an inline 6 for the V8, a buddy of mine has had a pile of these trucks, with both motors, and he has consistently found that the V8's actually have better mileage, until you start driving it hard. Especially for you pulling stumps and really using the truck, the V8 is most likely the better all around engine.

He usually averaged about 15 MPG, but his is 2WD. How is your truck mechanically? Plugs, wires, cap, timing, fuel filter, etc.?

why wouldn't you suggest it? ford used the 300 everything including larger dump trucks, many weighing into the 15,000–20,000 pound (7,000–9,000 kg) range. and a 4.9 will out last a 5.0. the 4.9 has a bulletproof reputation and its known for its low end torque by every one .

[jakobnev]

If it was my project, i think i'd start by looking at the possibility of making hinged rocker arms with a lock pin that can snap back into place while the pushrod isn't, pushing.

[kanoshee]

Originally Posted by jakobnev

If it was my project, i think i'd start by looking at the possibility of making hinged rocker arms with a lock pin that can snap back into place while the pushrod isn't, pushing.

thanks for getting us back on track lol, uhm... how would i do that?
i don't even know what hinged rocker arms are. i had a nice paper wrote up on chevy's system from some free car-quest diagnostic course i took in college but i can't find it anymore

[kanoshee]

Originally Posted by c_silva88

my 84 has a computer controlled carb which uses an o2 sensor to adjust the air/fuel mixture. and even with the computer controlled stuff acting up ( runs extremely rich)i can consistently get 18mpg out of the 4.9. now swapping a 4.9 in place of your 5.0 is straight forward you can use you current wiring and transmission i can walk through the swap as far in what you'll need and what to do wiring wise, i've done a couple.and complete motors can be had for cheap.




why wouldn't you suggest it? ford used the 300 everything including larger dump trucks, many weighing into the 15,000–20,000 pound (7,000–9,000 kg) range. and a 4.9 will out last a 5.0. the 4.9 has a bulletproof reputation and its known for its low end torque by every one .

yeah i find it real hard to believe any v is better than any inline i'm a big inline fan and if i had the money i would put either a straight six or 4 diesel in it. when i was in college there was this 4cyl diesel we had in the shop that we did alot of work on and it just seemed perfect for any fullsize pickup. but they're pretty rare everybody wants power power power! so they get that "cummings" or powerstroke. or whatever else. i believe this little thing was an older Detroit diesel had 2 separate heads and valve covers it was a regular sized industrial engine made to be rebuilt and reliable. doubt the mileage would of been that great but couldn't of been that bad. the V style in design is inferior, it sits always angled and always has to fight against itself

[2000neon]

Originally Posted by c_silva88

why wouldn't you suggest it? ford used the 300 everything including larger dump trucks, many weighing into the 15,000–20,000 pound (7,000–9,000 kg) range. and a 4.9 will out last a 5.0. the 4.9 has a bulletproof reputation and its known for its low end torque by every one .

After seeing a bunch of my buddies trucks,and driving a number of them, I've always preferred the V8. I've personally seen and used the torque of the 300, and they are certainly capable motors. But when just driving lightly, without flooring it the V8's have always given better fuel economy, and that is with 2 trucks with the 5.0 truck motor, and one that had the I6 and was swapped with a 5.0 HO.

Also when towing a car trailer with a 3900 lb car on it, the V8 seemed to do ot a whole lot easier, although fuel economy was worse with the v8 while towing. In my experiences, I prefer the V8, but I could see why people like the 6.

[kanoshee]

Originally Posted by jakobnev

If it was my project, i think i'd start by looking at the possibility of making hinged rocker arms with a lock pin that can snap back into place while the pushrod isn't, pushing.

what about something in the spark plugs, if i could get a solenoid to apply or relive the pressure on the spark plugs? thus relieving compression i un derstand they negative consequences but, how MUCH oil would it throw out during that time? and HOW much pressure do the spark plugs need to stay in place?