Now it's all about the tuning...

[John Smith]

It's been a while since i had updated some progress on my new/old carb/duraspark situation..

After getting it running satisfactorily i got busy rebuilding the "CV"drive-line, the total brake system, and adding a complete new exhaust and since it's been kind brisk outside..I took a little time.

I know have manual brakes, manual steering, and have road tested this carb/diz combo to have a few few questions for some who are "experienced"..

and BTW, i now have a new "timing light"..after doing my "road-timing-testing-to-find the right timing setting for the gas I'm running"..I still have a slight detonation when letting off the throttle..so i thought i would check the "TOTAL TIMING" of this 2.8L with my current diz. ( I should say that my initial plan of "road testing to find the right timing l needed worked just fine,...but i was experiencing a little detonation of the "backing off " of the throttle after a hard accelerate so after retarding the timing i wanted to double check it with a light to be sure of things and "I WAS ACTUAL ONLY ABOUT 2 DEGREES RETARDED "ie..8 DEGREES ADVANCE"..it kinda built my faith again in what i had learned years ago...i guess not much has changed in carb and distributors...anyway..I should say that when i bought a "duraspark" diz..i bought a "dual vacuum" diz that i found at a local parts store at a good price that had a good mainshaft bushing..(after returning (2) XX..2691's to a local box store for bad bushings after ordering)..anyway..the car runs great..but the curiosity of TOTAL TIMING comes up after checking my timing with my new whiz-bang timing light...I think my "dual-diaphragm" diz may be set up for more advance than i may need comparing to a typical single diaphragm unit. I don't cherish the thought of a different ziz..but some diz tuning may be possible with what i have if i can get it to within the total timing needs of this 2.8L in stock configuration given the gas we use today..albeit set back to 78 Mustang II specs

I know that EGR working properly can help with detonation...along with a gas/grade upgrade at some altitudes..At this point an EGR is not what I am considering so any total timing input is welcome along with any gas-grade upgrades..to help with that situation...anyway..it's all good and has been and continues to be a kewl thing to fiddle with....kinda neat cruisin' down the avenue with a v-6 purrin' that starts instantly anytime you want it to....best wishes ..

replies welcome

 

[kimcrwbr1]

I have spent alot of time experimenting with different timing adjustments and carb settings. The way mine is now timing is at 10 degrees and idle air are about 2 1/2 turns out and I have the egr working off ported vac on the carb. For the egr I bought one with two vacuum ports on it one goes through a temp switch and turns on aroud 135 degrees, Ported vac from the carb thru the vacuum switch to the egr. The other port on the egr I have a vacuum restrictor in line and pull the vac from the air horn on the carb (filtered air) The way it is working when you open the throttle and manifold vac is at 20hg it gives me almost 4 inches in mercury to the egr to open it slightly. The egr I got has a variety of washers I put in second to smallest. EGR stays closed at an idle and low vacuum pressure and allows exhaust gas to circulate at high vacuum pressures. Different restrictors allow different vacuum pressures its working real good right now. For my idle air I have a hand held carbon monoxide detector and put in a new cat I feed air full time at the ports on the head. Turn the idle air out 3 1/2 turns and get the engine up to temp and adjust for the highest smooth idle speed possable then checked the CO coming out was about 80 ppm slowly turn the idle air in 1/4 turn on both needles until I get a zero ppm on the CO reading. Then to balance sides turn the idle air out one at a time until it reads CO then back in to zero. My choke, air pump, egr, vapor cannister are all working just fine. Next on my list is the curb idle plunger Im gonna set it up so when you put it in gear it will raise the idle speed automatic using the neutral safety switch a relay and a pod. But that is another day after I go through the tranny.

 

[kimcrwbr1]

http://www.ebay.com/itm/TOMCO-10427...ar:1978|Make:Ford&vxp=mtr&hash=item415767fabe This is the egr I put in but only paid $34 + shipping using the same part number

 

[drgrcr]

If you decide to install a working egr system to your engine, you will need to add additional spark advance during the same time the egr is applied. How much depends upon the variables that the vehicle is equipped with. Like axle ratio, transmission, and altitude. EGR cools the combustion process and requires additional spark lead to keep to get the same cylinder pressure. During the 80's if you came across an engine that was running fine for about 70-80k mile and then slowly started detonating (pinging) more noticeable at cruise, usually the egr had plugged, and the additional spark lead required during egr operation would now cause engine detonation.

I have heard the argument that egr will help fuel economy....but never saw it proved, egr is thought to reduce pumping losses, but it also dilutes the air charge mixture with exhaust gas, the idea is to reduce NOX emission. One of the reason 80's type vehicle had reduced compression ratio's...it was a very messed up time for vehicle emissions, modern engines compression are back in the 10.1 range and use very little egr, of course due to better over all cylinder head design. And much improved fuel economy and HP.

Since we are all just playing with these old dinosaurs, I guess it would be what your goal is. Improved performance/fuel economy or tweaking the engine for reduce emissions. Mine is performance and fuel economy.

I had a lot of experience with Ford engine calibration work during the 80's and beyond. Ford has been very good to me...

 

[John Smith]

some very good input from both of you above

I originally got involved with these B2's to install a 2.3L variant into one and fiddle with it as long as I could still work on one. In the process I have acquired this this 84 as a candidate for a transplant and am now just working with this 2.8L as long as the engine is healthy. The question of EGR is a good one because of another vehicle i own a recently acquired F150 (an 83) that will need some attention in the same area as it now has the infamous "california" EECIII/DSIII combo. It is not running well and will get some attention in a month or so.

My 88 B2 has no EGR from the factory..my 2.8L 84 now only has
"port" vacuum with no EGR. I would like to run it that way but i can tell I may need to back off the advance curve some (probably by custom tuning the diz either centrifugal or vacuum or both) to make it run optimal. It may be not really practical w/o some other compression mods etc like you have said..to make it run optimal. Good discussion and this was what i was hoping for..some input on maximum total advance w/o EGR would be good to know. I think by looking at the total advance now..i may have too much under port Vacuum with this dual vacuum diz can. I may have to get this diz curved or try some tweaking of the centrifugal ..springs etc.. Does anyone know if you can get an adjustable vacuum advance can?...or is the one i have adjustable?...I guess i should check...

I CAN go back to EGR if need be..I have another manifold to work with...but before i do that i will tweak the timing curve in some way..

Anyway coming up with a workable EGR w/o any computer input is a good if a person wants to retain it for whatever reason...and diagrams for wiring/plumbing for same would be good as well...if a person would dare post any of that...

Again thanks for the input...

 

[kimcrwbr1]

I was trying to figure out how to get the egr working using the position sensor but you need other computer inputs to control it as in MAP and O2. Using a VRDV as a relief on the egr pod it regulates the vacuum pressure to the egr. I grabbed some at the bone yard not knowing what they were really called found out last nite. Its called a vacuum delay valve. I put one on the vacuum from manifold to the vapor cannister what it does is restricts the vacuum to the cannister without affecting engine vacuum sort of an orifice, I got the idea from my jeeps PCV system all it had was a orifice strait off the manifold vac. I forgot to mention my engine runs best on manifold vacuum to the distributor advance. Have you tried tuning it like that I get a much better idle with it at 20 btdc at an idle. The VRDV delay valve was also used for the dizzy advance but there is one on the preheater door on the air filter housing also. I didnt think about possibly advancing the timing with the egr now working I will give it a shot.

 

[kimcrwbr1]

 

[kimcrwbr1]

 

[John Smith]

kudos 4 the work on the EGR

I was trying to figure out how to...Using a VRDV as a relief on the egr pod it regulates the vacuum pressure to the egr. I grabbed some at the bone yard not knowing what they were really called found out last nite. ....Have you tried tuning it like that I get a much better idle with it at 20 btdc at an idle. The VRDV delay valve was also used for the dizzy advance but there is one on the preheater door on the air filter housing also. I didn't think about possibly advancing the timing with the egr now working I will give it a shot.

The VRDV I am familiar with but have not decided to hook up a working EGR just yet...

It seems in it's stock form the intake manifold with the EGR passages built in are great if ur using the EGR but not so good if it's UN-used..It may just become a large heat trap neath the carb?.. Before i mod the intake some more..i want to think about that..

I can tell i want to re-curve this diz for max advance at 36 degrees or so and i would prefer to use the ported vacuum although it does idle a little better at manifold vac

It's obvious this motor as came in 84 was to be used as a smog motor with all the whistles..and may need some tweaking all around to run well for performance AND economy..but we'll take some more time now that it's running to work on that and in time we'll get there hopefully with closer to 20 mpg... and with my now MANUAL steering..which works fine BTW, I certainly won't be running anything bigger that 215's or so to keep the rolling/turning resistance at a minimum...

the saga continues...next to take out the diz and work on TOTAL advance..we'll see

 

[kimcrwbr1]

I put the B-II wheels on my ranger with 215s from 14" to 15" and changed the speedo gear in the tranny so the speedo is pretty close I figure I`m getting around 17-18 hwy mpg. When I did the duraspark conversion I changed the valve guide seals and resealed the intake manifold. It took about two hrs to clean out the egr ports on the heads and intake manifold they were completely plugged with carbon buildup. I have had the frame sitting on the rear axle a few times with wet compost and she runs just fine. For as many times the engine overheated or the oil pressure dropped I have no problem trying different settings, But I am pretty happy right now I am tempted to have it put on a machine and see if it passes emissions as it is. I did find the curb idle solenoid I just have to figure out which wire the computer used to switch it on with.

 

[John Smith]

all good info...

I put the B-II wheels on my ranger with 215s from 14" to 15" and changed the speedo gear in the tranny so the speedo is pretty close I figure I`m getting around 17-18 hwy mpg. When I did the duraspark conversion I changed the valve guide seals and resealed the intake manifold. It took about two hrs to clean out the egr ports on the heads and intake manifold they were completely plugged with carbon buildup. I have had the frame sitting on the rear axle a few times with wet compost and she runs just fine. For as many times the engine overheated or the oil pressure dropped I have no problem trying different settings, But I am pretty happy right now I am tempted to have it put on a machine and see if it passes emissions as it is. I did find the curb idle solenoid I just have to figure out which wire the computer used to switch it on with.

I know you've done a lot of work with this motor and you're probably doing pretty good for MPG with an auto even wouldn't you think?..

I know i need to change the stem seals..it had never ran w/o the factory stuff till last week so after a few miles on the open road I'll start tuning a little myself. (maybe i should sea-foam it to help get rid of carbon?..it had high compression already 165+) It still has the "40" jets in it from the carb rebuild and I want to read the plugs and tail pipe good before making a change. If i can just get the vac advance slowed down I can give it a good test...Tomorrow i need to put the dash back in it so i can see what everything is doing gauge wise..

If I'm lucky i may have an adjustable vacuum can already..some do I guess we'll see tomorrow as well if i get to it..

I think i would like to curve the diz for a spread of about 12-14 base to 36 or so full out...that's just a rough idea at this point..

I found a few other posts online re: curbing the vac adv when not using an EGR ..even one post re: a v-6 cologne..(although there is more info about Ford v-8's) (and of course crane sells an adjustable vac advance for Ford diz's) must not be the only one to ever want to check that out..I guess we could get a custom diz..(Msd. Mallory) and get the adjust-ability of all of it..but we'll see what i can do with a factory diz "on-the-cheap" first.

but i DO now have some parts numbers for adjustable vac adv cans...

If you ever need any 84-85 parts...i have quite a few including extra carbs, solenoids, etc..always glad to donate a few parts to "research"...

cya

 

[kimcrwbr1]

http://www.ebay.com/itm/Neiko-Tools..._Automotive_Tools&vxp=mtr&hash=item35b93929bc I bought one of these and hooked my compression testor up to the compressor at 30lbs pressure to hold the valves up while changing seals. Just put the cylinder on tdc your working on, I just followed the firing order using a long screwdriver in the plug hole to feel when the piston was all the way up. Just be careful of the keepers I put a little pressure on the spring first and give it a tap with the hammer to break it loose first then compressed it all the way to take the keepers out. I almost had one fall in the drain hole down into the crankcase the gunk on the head kept it from falling in. I couldnt find a MSD dizzy for the 2.8 it would be nice to be able to control the curve electronically I believe mallory has them but not much difference to the duraspark it still has the vacuum mechanical advance. The TFI dizzy was nice in the fact it was controlled by the knock sensor and would advance it to the point of detonation and retard it accordingly with the foot feed. The main problem is the computer had so many inputs if something was wrong it would default to limp mode and the advance was disabled and run the engine on base timing 10 degrees full time.

 

[John Smith]

well for my purpose...

http://www.ebay.com/itm/Neiko-Tools..._Automotive_Tools&vxp=mtr&hash=item35b93929bc I bought one of these and hooked my compression testor up to the compressor at 30lbs pressure to hold the valves up while changing seals. Just put the cylinder on tdc your working on, I just followed the firing order using a long screwdriver in the plug hole to feel when the piston was all the way up. Just be careful of the keepers I put a little pressure on the spring first and give it a tap with the hammer to break it loose first then compressed it all the way to take the keepers out. I almost had one fall in the drain hole down into the crankcase the gunk on the head kept it from falling in. I couldnt find a MSD dizzy for the 2.8 it would be nice to be able to control the curve electronically I believe mallory has them but not much difference to the duraspark it still has the vacuum mechanical advance. The TFI dizzy was nice in the fact it was controlled by the knock sensor and would advance it to the point of detonation and retard it accordingly with the foot feed. The main problem is the computer had so many inputs if something was wrong it would default to limp mode and the advance was disabled and run the engine on base timing 10 degrees full time.

I can do w/o anything BUT manual advance/retard on a diz so any diz with an actual advance can is what would pay money for..since I have removed any computer...i would prefer to be w/o any future use of a pewter if at all possible...as fun and as kewl as they are with all DUE respect to those who use them... so..on with the quest to see if this 2.8L can run successfully and adequately w/o any pewter...been there , done THAT, DON'T need it anymore....

have a great week....

 

[drgrcr]

If your lucky, you mave have a adjustable vacuum pot on the dizzy, remove the vacuum hose from the dizzy and stick a 1/8" allen wrench in the hole if it is you will feel the wrench go into the hex. Turn it clockwise to increase spring tension which will decrease ported vacuum advance. Find a vacuum gauge and use it while driving too get an idea as to your style.

I currently have mine timing set at 36' total at 3k rpm, and have have 48' at around 14" of vacuum. Works well where I drive the most which is between 3300 to 4000 ft altitude. I did drive it down to a 600' altitude ambient temp was a nice balmy 70' and humidity at 6%...it happens in AZ, worse case for detonation and it was detonating...I was a little nervous about gaskets and pistons until I started climbing out of the valley at around 2k altitude it calmed down and we came home.

MSD use to sell a replacement Duraspark module that had a adjustable timing knob that mounted inside of the vehicle, gave you 15' of adjustment while driving which would have worked just right for the condition I had.

I currently have the 1.08 carb that has the meter rods that work of a cam on the throttle shaft, have a 44 main jet and stuck with the rebuild power valve that opens around 6" of vacuum, dont know what the power valve circuit size is. Currently getting 17-18 mpg around town. I too have the BII 15' wheels with P205 tire and a 3.08 axle ratio. The famous 3 speed C3 trans. Planning on rebuilding the engine real soon. Going to junk yard next week to pick up a set of heads and start doing some port work, install harden exhaust seats and 2.9 valves. When I get done the compression ratio will be very close 10.1....The plan is to get the tune right and be able to run it on 87 octane fuel....thats the plan anyway. After the engine rebuild I have a A4LD trans from a 84 that will be rebuilt and installed, then change the rear axle ration to a 3.73.

Why?....cuz that's what goofy old drag racer do...

 

[John Smith]

well..

If your lucky, you mave have a adjustable vacuum pot on the dizzy, remove the vacuum hose from the dizzy and stick a 1/8" allen wrench in the hole if it is you will feel the wrench go into the hex. ...The plan is to get the tune right and be able to run it on 87 octane fuel....thats the plan anyway. After the engine rebuild I have a A4LD trans from a 84 that will be rebuilt and installed, then change the rear axle ration to a 3.73. Why?....cuz that's what goofy old drag racer do...

I understand...

Well, 2day I finally got to the diz and found...It's adjustable. For some reason to get mine adjusted where I wanted it I ad to turn it CCW but no matter, It runs acceptably now,..(I should add that I ran a can of sea-foam thru the carb, and also topped off the tank with about 4 gallons pf premium.)...runs much better, and at least now i can begin to put a few miles on it to further "dial it in". Took it out on the freeway and after listening to it idle and sampling the tailpipe..I think it will only get better in the next 200 miles or so of sustained driving...

I got a couple sets of jets in 2day as well (42's and 44's)..I'll see how it goes in a few more miles before it experiment with any changes...

In the mean time I bought a set of new plug wires and brass cap and rotor so we'll give it a fair shakedown...

I sure like the way it starts..no touch of throttle 1 click and it's alive.(warm start)..starts quicker than my EFI 88 (on a cold start i just have to give it 1 short pump then hit the starter...runs like a champ)...

It's been a good day in the hood, no serious scraping of knuckles, or sprang-ed ankles, so till I guess till the next chapter, ..carry on...

on edit..I'll say, drgrcr, mine already has the 3:73, and OD TK5 so I'll be checking that MPG for the next few miles and will report...