Engine Cpt Vacuum Users and Emissions

[scoutpappa]

the electric choke system is not an "emissions" deal. It is a painless/troublefree (when adjusted correctly) carburetor circuit.

These aftermarket carbs when rigged with the electric choke make the starting drill (hot or cold) a no-brainer once the sequence is learned. Yawl are too young to remember carbureted vehicles when each model had a starting drill explained in the owner's manual. Hell, in texas...that was part of the driver's education curriculum (I taught driver's ed for several years), how to cold start a car and how to change a flat tire! But by the time I started teaching we had electric starters and did not have to learn how to hand crank.

The electric choke operation is an engineered, timed curve. Those do not meet any emissions criteria for any vehicle in any year model, these are completely for aftermarket conversions on performance applications. And even if an engine is "hot", it still benefits from having a choke partially actuated for restart. I deal with folks all the time that say..."it's hot here, I don't need a choke"...I tell 'em bullshit, every engine needs a choke if it's carbureted. Ambient air or engine temperature have nothing to do with starting an engine or providing a proper air/fuel ratio as the engine goes through warm-up. And an electronic fuel injected engine is no different, the a/f ratio is constantly being tweeked by the computer based upon sensor inputs from many sources as the engine goes from cold to normal operating temp,...thousands of times per minute.

Mechanical fuel injection with no dam computer...same thing based upon temperatures, etc. As throttle air bypass is temperature controlled, that acts like a "controlled" air leak on those systems. It works continuously, hot or cold engine temp/ambient air temp.

I am constantly learning something from you. I think I have the choke circuit set. Set the high idle and have a good switched source so tomorrow morning my wife and I will fire it up cold. It's 70 here and going to be quite a while before the block gets cold so I can show her a true cold start and after that we can practice with the warm starts.

 

[Michael Mayben]

A practice session or two will make this all golden!

And...a "cold" engine is any engine that has not been run for at least 20 minutes. "cold" and "hot" in the engine world are not related to ambient, but to the internal engine temp, oil temp, and coolant temp.

70*f ambient air temp to an engine/carb is just as "cold" as 30*f ambient air or even 0*f ambient air. Same holds true for efi, same holds true for diesel, same holds true for your lawnmower and weedwhacker. Same holds true for your chainsaw.

The electric choke element begins cooling immediately when current is turned off, that has nothing to do with engine temp, ambient temp, or anything else. Even with an underhood temp of say 175*f (a 15 minute heatsoak in the wallyworld parking lot), the electric choke will be nearly fully closed, that is exactly how it's supposed to work.

In extreme cases of coldsoak ambients (say <0*f), the electric choke "might" open too quickly, so we can add an additional electrical device to the choke b+ feed that serves to slow down it's action, but I don't use those on my own stuff with electric chokes (all my IH rigs have electric choke conversions, even the Scout 80 as of this morning!). I use 'em in ambients of an "average 3>5*f to 25*f here in the winter months (it was 23*f here this morning and both the rigs popped off just as fast as the efi dodge), that is with a near 100% humidity since it rains or snows constantly. And that is at our base altitude of 670ft. Up to around 6200 ft. Where we travel/play.

 

[scoutpappa]

First and foremost, happy new years to you and yours and to everyone who looks at these threads. I hope to all a prosperous year so eat all the cabbage and black eyed peas you can stomach. Mike/Jeff, the choke works and works well. Thanks for the patience and guidence. Next week is the cd box so at that point I should have the fuel delivery and ignition part of this truck operational and correct. Then on to complete elimination of all the half assed removal of the emissions. Then another shopping trip at IHOnly to get reverse light sockets. Then on to the new a/c system and then a rewire and power window kits from IHOnly and power locks too. By then hopefully she is tired of it and we have found her dream truck to start. A 68' Travelall. Oh boy

 

[Michael Mayben]

first and foremost, happy new years to you and yours and to everyone who looks at these threads. I hope to all a prosperous year so eat all the cabbage and black eyed peas you can stomach. Mike/Jeff, the choke works and works well. Thanks for the patience and guidence. Next week is the cd box so at that point I should have the fuel delivery and ignition part of this truck operational and correct. Then on to complete elimination of all the half assed removal of the emissions. Then another shopping trip at IHOnly to get reverse light sockets. Then on to the new a/c system and then a rewire and power window kits from IHOnly and power locks too. By then hopefully she is tired of it and we have found her dream truck to start. A 68' Travelall. Oh boy

I just had new year's breakfast man...blackeye peas, collard greens and hot sauce, and smash taters with the skin on! All that's lackin' is chikinfry steak!

So obviously the cold-start training session went ok? Yawl still speakin'???

We can find yawl a roundbody t'all, ya wanna 2x4 or a 4x4??? With rot or without? A driver or a project?

 

[scoutpappa]

I would like to find a 4wd with little to no body rust that could be used as a driver to start. Now considering that I am building a little confidence with dealing with these trucks driver could constitute needing a new ignition and carb, but having a soilid drivetrain and engine. I can get around to fixing alot of the throwaway maintenance items like alternator and accesories. Just don't want to have to redo all the body before I even get to mechanical operation items. And even though she is comfortable with driving a standard in a vehicle this old I would like to get something that I could either add an od too or swap out a transmission to get taller gears. In the end I would like to be able to take the vehicle to la at the posted speed limit without running at 3k+ rpms and all the wear and tear that brings in. That being my wish list.

 

[scoutpappa]

Just got my new 6852m cd ignition box and 30440 promaster e coil. Hell yeah. Now if only I can find a parts house that has a gd fuse block. Houston sucks. Any tips on this one? Will I have to readjust my carb and timing with this new componant? I have a feeling the answer is yes, but after reading Mike's thread where he is playing around with different ignition options I have high hopes for this.

 

[Michael Mayben]

I would like to find a 4wd with little to no body rust that could be used as a driver to start. Now considering that I am building a little confidence with dealing with these trucks driver could constitute needing a new ignition and carb, but having a soilid drivetrain and engine. I can get around to fixing alot of the throwaway maintenance items like alternator and accesories. Just don't want to have to redo all the body before I even get to mechanical operation items. And even though she is comfortable with driving a standard in a vehicle this old I would like to get something that I could either add an od too or swap out a transmission to get taller gears. In the end I would like to be able to take the vehicle to la at the posted speed limit without running at 3k+ rpms and all the wear and tear that brings in. That being my wish list.

The typical "d" series 4x4 t'all is going to be equipped with 3.73 gears oem. A roundbody would be more commonly found with 4.10 but 3.73 was also just as common.

With a 33" tire, that will give a cruise rpm of a nominal 2800rpm and that is real world considering the frontal area of two sheets of plywood and an average curb weight of 5200lbs. Expect typical fuel consumption at that speed/load of 10mpg onna perfectly tuned 392. Keep in mind I have two of these rigs that even though they each have different 392 engine setups (one has not had the oem heads off in over 250k, the other is totally "built", cost no object engine), they perform the same, get the same type of fuel consumption (with 5mpg fully loaded pulling a 6klb. Trailer load).

These engines were designed to run 24/7/365 at max rated rpm under load. That is what makes 'em truck engines and not a sbc!

The beater truck has now had a 4.10-geared dually rear axle installed which hugely enhances trailer pulling, increased "cruise" rpm by 100>200, and decreased fuel consumption by 1mpg when towing. I originally had a 4.56 axle to use and certainly would have been absolutely perfect and May still be in the cards in the future if I keep developing that vehicle.

These various "gear calculators" don't mean squat on these trucks in the real world of air drag, rolling resistance, and 5,000lb.+ rolling load!

 

[Michael Mayben]

just got my new 6852m cd ignition box and 30440 promaster e coil. Hell yeah. Now if only I can find a parts house that has a gd fuse block. Houston sucks. Any tips on this one? Will I have to readjust my carb and timing with this new componant? I have a feeling the answer is yes, but after reading Mike's thread where he is playing around with different ignition options I have high hopes for this.

If you think that your current base timing setup is working well as is, then simply installing the cd box and coil won't change anything as concerns "timing". Timing is determined (and maintained) by the distributor trigger, and you have one of the best, most stable triggers (technically-speaking) that is currently available for any spark ignition system.

So...do not touch the distributor (except for making the trigger connection to the new mallory box).

What you are going to be able to "feel" and "hear" is a new level of smoothness, a bit crisper throttle response right off idle, and most likely a slight increase in curb idle speed on that new carb. So once it's all running and fully up to temp, you will prolly need to tweek the curb idle downward just slightly, this is because that ignition system is vastly more efficient at lower engine rpm where it is most effective for these truck engines!

 

[scoutpappa]

if you think that your current base timing setup is working well as is, then simply installing the cd box and coil won't change anything as concerns "timing". Timing is determined (and maintained) by the distributor trigger, and you have one of the best, most stable triggers (technically-speaking) that is currently available for any spark ignition system.

So...do not touch the distributor (except for making the trigger connection to the new mallory box).

What you are going to be able to "feel" and "hear" is a new level of smoothness, a bit crisper throttle response right off idle, and most likely a slight increase in curb idle speed on that new carb. So once it's all running and fully up to temp, you will prolly need to tweek the curb idle downward just slightly, this is because that ignition system is vastly more efficient at lower engine rpm where it is most effective for these truck engines!

I do need to power tune so will cross that bridge when I am finished. I can't wait to install this. You would think that an industrial I&e outfit would have at least a few feet of #2 or #2/0 but no we've been wiped out so I'll settle for thhn/thwn #6 which is good for 75a. My local autozone does not have a fuse panel. Does anyone know of a store o'reilly, napa, whoever, that regularly carries the little extension fuse panels. That is the only part I lack to do this right the first time. And Mike I definately want to continue the discussion about options for an older traveall and possible drivetrain conversions. I May start another thread for ideas and discussion in the chit chat thread. I would want to keep an IH motor but it would seem that there would be one or two auto options in the IH line that would have taller forward gears and an od with the swap out of the diff gears. Ehh just thinking. I know I am basically trying to bull a heavy unaerodynamic vehicle at probably suicidal speeds (75) down the road, but was thinking of the olda adage that 80% of the wear and tear on a motor happens in the last 20% of the motors capability.

 

[Michael Mayben]

Don't let my comments regarding not hooking directly to the battery stand in your way. You can always go back later and revise the hookup. My electron-related stuff always "evolves" over time as I continuously tinker, clean up wiring, and work out more elegant solutions to this stuff.

Just yesterday afternoon I stumbled across some more low voltage electrical treasure at one of my local parts sources that they had brought in out of a off-site warehouse. Then I schooled a few club members about this same thing at our club meeting last night.

The o'reilly points I use up here have the buss auxiliary panels hanging on the wall with all the other diy electrical stuff, fuses, circuit breakers, wire terminals, etc.

 

[scoutpappa]

don't let my comments regarding not hooking directly to the battery stand in your way. You can always go back later and revise the hookup. My electron-related stuff always "evolves" over time as I continuously tinker, clean up wiring, and work out more elegant solutions to this stuff.

Just yesterday afternoon I stumbled across some more low voltage electrical treasure at one of my local parts sources that they had brought in out of a off-site warehouse. Then I schooled a few club members about this same thing at our club meeting last night.

The o'reilly points I use up here have the buss auxiliary panels hanging on the wall with all the other diy electrical stuff, fuses, circuit breakers, wire terminals, etc.

I got lucky. Advance didn't know they had them, but my office is in deer park so basically I had to drive thirty miles to find one store that had it. Kingwood is not really the do it yourself area of houston, so for the most part they have screw/glue on fake chrome shit all over the stores. So now I can copy the installation you posted previously. Man, I'm excited about this. Weird because I have quite a bit to do to get a finished installation.

 

[scoutpappa]

Alright. Got it all installed and it actually started. But of course I have a question. The instructions say that when you turn the key you get a blinking led (3 times) at the back of the unit. Check. We get that. When we crank the engine the light blinks. When the engine fires and runs we get a constant light. The instructions suck. Direct quote if, after a normal power up, the led doesn't flash when cranking the engine, you should check your triggering circuit for problems. If the led flashes when the engine is cranked, but there is still no spark, the problem lies somewhere else. Wth does this mean. I have a constant light when the engine is running. I posted a question on mallorys' site but they only work two days a week. I have good throttle until about half throttle and then she develops a sustained miss at constant half throttle. Before I go chasing ghosts I figured I'd check and see if anyone has any thoughts on this. I know at least one person has the same cd box. I mean it runs so...it works right? I also have the power filter installed and am wondering if that can affect how it runs. I took out the ballast resistor and left in the power filter. Kinda pointless now since I am only signaling the cd box and of course there are no instructions pertaining to that little gem. I'm really hoping I need to re time and re set the carb.

 

[Michael Mayben]

First off, I'd ditch the "power filter". I've never had any use for those devices.

Again no ballast resistor is used when using the unilite to trigger the 6a box. It is only used with the unilite for triggering a coil in the conventional "inductive" system.

You have probably looked at the complete wiring system several times. Take a break, then look at it again. Are you certain that you did not use the mag trigger input, it should simply be left dangling for now and not connected to anything...ever.

If you connected a tachometer of any type to the yellow "tach wire", disconnect that and leave it disconnected until the system performs perfectly.

The unilite pigtail has three wires coming out, is the brown wire connected to a clean engine ground? Is the polarity and connection of the other two wires correct?

Are the two wire connections at the coil correct? Reversed polarity will cause the upper rpm mis/scatter fire phenomena.

Verify all the above and report back!

 

[scoutpappa]

first off, I'd ditch the "power filter". I've never had any use for those devices.

Again no ballast resistor is used when using the unilite to trigger the 6a box. It is only used with the unilite for triggering a coil in the conventional "inductive" system.

You have probably looked at the complete wiring system several times. Take a break, then look at it again. Are you certain that you did not use the mag trigger input, it should simply be left dangling for now and not connected to anything...ever.

If you connected a tachometer of any type to the yellow "tach wire", disconnect that and leave it disconnected until the system performs perfectly.

The unilite pigtail has three wires coming out, is the brown wire connected to a clean engine ground? Is the polarity and connection of the other two wires correct?

Are the two wire connections at the coil correct? Reversed polarity will cause the upper rpm mis/scatter fire phenomena.

Verify all the above and report back!

First step- I verified that the coil had the correct polarity. In this case factory harness yellow cable = +
black cable = -
to 6 box orange = +
black = -

all in order. Polarity verified. Started up no change

pulled power filter. Verified pins contacting verified color match
green to green brown to brown red to red

all in order. Started no change.

Added ground cable from battery to ground post on body that I was utilizing for the power circuit ground.

Started no change

took brown cable from dizzy off of bolt that holds the factory coil and ran it to the ground post connected to battery (#6 wire to battery negative 0/0 guage to block.)

started no change

started no change = smooth till upper rpm then consistent miss.

Wired to mallory instructions as follows

dizzy = brown to battery ground tied to block (last attempt)
red to 12 vdc b+ switched no ballast resistor
green to white wire from 6 box

6 box = red power to fuse block post to starter post to battery positive
black to firewall post to battery negative
orange wire to coil yellow wire positive
black coil wire to black wire on coil harness negative
white wire to green wire dizzy signal
yellow wire butt spliced and wrapped in 33
purple/green wir harness wrapped in 33

I did not hook up my meter to see at what rpm the stutter starts. I will have to do that tomorrow when I can figure out how to get a clamp on the negative side.

I have not changed the plugs yet and they are gapped at .035 so I am sure they are not in great shape as these plugs were in with the 500cfm carb

I retermed the coil wire with the new end terminal and rubber cap

I verified that the wires were not touching and as of right now I don't see any evidence of arcing.

After each change I checked that when the key went to the on position I had three flashes
the truck starts almost immediately so it looked like it flashed when cranking
when the engine catches the led glows constantly. No blinking led while running in any iteration described above. I am using weather proof quick connects right now so outside of splicing the white wire directly to the green wire I think I have continuity across the terminals. I have not verified this with a meter.

This is wired per figure 10 (mallory unilite of magnetic breakerless dizzy hookup schematic) of the mallory instructions provided with the 6 box.

Ehhh. Lsu kicked a&ms' ass so I think I am going to bed now.

Really and truly it could be something else but I keep going back to the red led in the box not blinking when running. If it is supposed to be on steady then I have another issue. If it is then I have a signal issue but man this is a one wire hook up.

 

[Michael Mayben]

Thanks for confirming the wiring, this is exactly how diagnostics are done!

The led "action" tells me all conditions are correct. The led will glow when running since the "on/off/on/off" etc. Of the triggering is so rapid, at higher rpm you won't discern any change in the appearance of the led. If you were triggering the box from a breaker point set, you might discern a slight variation of the led since points aren't a "clean" switch, with any form of electronic trigger the switching is "fast" and "clean", thus the superiority over points.

Fresh plugs can be gapped at no greater than a 0.045" setting. That will take advantage of the greatly enhanced output characteristics of the cd ignition combined with the capabilities of that coil. I'd recommend autolite 85 since those are a known heat range for these engines, you have absolutely no need to differ from that heat range selection. An autolite 303 is also used in interchange with the 85 though the tip design is a bit different. I run 85 in all my stuff and never vary at all even though I do dick around with carbs and ignition stuff constantly. "brand name" of the plug selection has nothing to do with issues such as this and in most cases, the heat range of a "cross-reference" plug is always going to be slightly different.

I don't remember the situation with the plug wires...but keep in mind...this system is now pumping a nominal 35k>40k volts at about 130 millijoules across the plug gap to ionize. That is a far greater spark energy than any oem system ever thought about producing! This the plug cables, distributor cap, and the rotor must be high quality. The mallory cap and rotor are high end items, so unless physically damaged by dropping (resulting in a microscopic crack), they can't be beat. But plug cables need to be looked at. When you run the rig in the dark at higher rpm, you May see some "leakage" of spark energy. This system can "arc" in the atmosphere a distance greater than 2"!!!! And it hurts bad when it hits ya!

What I would do at this point is play with the distributor. Loosen the distributor clamp, have your wife hold the throttle position steady at the point where the scatter-firing begins, then slightly/slowly /minutely rotate the distributor counter-clockwise (to advance) and see if it cleans up. If no change, then rotate it same clockwise and see what happens. But a warning, if you have any "leaky" plug cable terminations close to the distributor, you are going to get bitten forcefully!

 

[scoutpappa]

thanks for confirming the wiring, this is exactly how diagnostics are done!

The led "action" tells me all conditions are correct. The led will glow when running since the "on/off/on/off" etc. Of the triggering is so rapid, at higher rpm you won't discern any change in the appearance of the led. If you were triggering the box from a breaker point set, you might discern a slight variation of the led since points aren't a "clean" switch, with any form of electronic trigger the switching is "fast" and "clean", thus the superiority over points.

Fresh plugs can be gapped at no greater than a 0.045" setting. That will take advantage of the greatly enhanced output characteristics of the cd ignition combined with the capabilities of that coil. I'd recommend autolite 85 since those are a known heat range for these engines, you have absolutely no need to differ from that heat range selection. An autolite 303 is also used in interchange with the 85 though the tip design is a bit different. I run 85 in all my stuff and never vary at all even though I do dick around with carbs and ignition stuff constantly. "brand name" of the plug selection has nothing to do with issues such as this and in most cases, the heat range of a "cross-reference" plug is always going to be slightly different.

I don't remember the situation with the plug wires...but keep in mind...this system is now pumping a nominal 35k>40k volts at about 130 millijoules across the plug gap to ionize. That is a far greater spark energy than any oem system ever thought about producing! This the plug cables, distributor cap, and the rotor must be high quality. The mallory cap and rotor are high end items, so unless physically damaged by dropping (resulting in a microscopic crack), they can't be beat. But plug cables need to be looked at. When you run the rig in the dark at higher rpm, you May see some "leakage" of spark energy. This system can "arc" in the atmosphere a distance greater than 2"!!!! And it hurts bad when it hits ya!

What I would do at this point is play with the distributor. Loosen the distributor clamp, have your wife hold the throttle position steady at the point where the scatter-firing begins, then slightly/slowly /minutely rotate the distributor counter-clockwise (to advance) and see if it cleans up. If no change, then rotate it same clockwise and see what happens. But a warning, if you have any "leaky" plug cable terminations close to the distributor, you are going to get bitten forcefully!

That is kind of where I am at in my thinking. The wires are the msd 8mm spiral wound street wire kit and I built them so that I could match the mallory cap and also get a straight end for the IH block. I have read a lot of peoples posts that deal with current jumps across the the cap. In this case the wires are about three months old as is the cap. I actually replaced it when I replaced the unilite module because the high leg tit came off the original cap that came with the distributor. I am also going to take the back cover off and make sure the dip switches are set correctly. I know the instructions say they caome set up from the factory for 8cyl etc but qa/qc ain't what it used to be. I'll report back after I try a few different individual changes and test the runability. In my head I was thinking that if the led flashed at each signal make then there was no way I could see a blink. I mean that is probably a contact made what once every 1000th of a second or faster? The light would be steady to the naked eye.

 

[scoutpappa]

Alright. I checked the dip switches and they were both on so I turned them both to off (no difference really just did it because both states are for v-8 application). No change. So I tried advancing the distributor no change or worse, so I started the retarding process and we have a winner, so for whatever reason I was a little too advanced on my timing for the new setup. This was all done in park so after I go get some new plugs and get them installed I'll go through the power timing scenario again. I don't have a timing light right now so I'll have to post the actuals and where I end up at a later date. I know that these readings don't have much to do with anything because it appears that people have their motors timed anywhere from tdc to 10-12 degrees advanced on this forum.

 

[Michael Mayben]

Great!

You are really understanding now the interaction of all this hi-tek" stuff when installed on old iron!

Don't be concerned with the "timing light" deal. While it's a good diagnostic tool, as you mentioned, all we care about is your engine, on your gasoline, operated under your intake setup, etc.

But...make certain to avoid any audible detonation (ping) using your normal gasoline supply. If at all concerned, then simply retard the distributor just a tiny amount for insurance. Every fillup of fuel has a slightly different actual octane rating depending upon where it was bended and how long since the thousands of gallons delivered to the retailer has set in bulk storage. "octane" of the fuel being dispensed varies tremendously, the only criteria is that "supposedly" it must at least meet the state and federal standard posted on the pump. In real world actuality, that don't mean shit and the octane can be all over the place.

Again let me reinforce, none of the so-called "specs" for tuning that are in the service manual, the underhood label, or in other folks experience mean shit, all we care about is your tune,....not my tune, or Jeff's tune, etc. This is the essence of performance tuning!!!

You have done a great job in sticking with this and you have corrected all the po virus-induced issues from the past! You have sure come a long ways since first posting!

 

[scoutpappa]

great!

You are really understanding now the interaction of all this hi-tek" stuff when installed on old iron!

Don't be concerned with the "timing light" deal. While it's a good diagnostic tool, as you mentioned, all we care about is your engine, on your gasoline, operated under your intake setup, etc.

But...make certain to avoid any audible detonation (ping) using your normal gasoline supply. If at all concerned, then simply retard the distributor just a tiny amount for insurance. Every fillup of fuel has a slightly different actual octane rating depending upon where it was bended and how long since the thousands of gallons delivered to the retailer has set in bulk storage. "octane" of the fuel being dispensed varies tremendously, the only criteria is that "supposedly" it must at least meet the state and federal standard posted on the pump. In real world actuality, that don't mean shit and the octane can be all over the place.

Again let me reinforce, none of the so-called "specs" for tuning that are in the service manual, the underhood label, or in other folks experience mean shit, all we care about is your tune,....not my tune, or Jeff's tune, etc. This is the essence of performance tuning!!!

You have done a great job in sticking with this and you have corrected all the po virus-induced issues from the past! You have sure come a long ways since first posting!

With excellent tutalige. I was getting my parts list together to go to the store. Gonna try to get the temp vac switches out and plugged and the air ports plugged too since I have to change the plugs out. On a very positive note I must have built the plug wires well cause I didn't get tossed on my ass by any leaking cables so those will stay installed. I don't have 4k miles on them yet. It is amazing that I can have the exact same setup as another Scout that is in the same area and have vastly differing timing/carb tunes installed to make that engine run. I guess I'll go with the theory that each Scout left is "special".

 

[towpainter3]

Each Scout is special!!!!! You can say that shit again!!!!!
Gotta say this thread has been educational and entertaining but not as entertaining as the linear gauge thread!!!!
Im still lost on that one too. God I love this forum!!!!