Now it's all about the tuning...

[John Smith]

An update..

I dropped some "44" main jets in the carb and it has pepped up the system a bit. I had added a can of seafoam in the fuel tank and after 100 miles or so it has settled into a pretty steady smooth running v-6. I can tell at my elevation (1100' above sea level) that 44's are going to be closer to ideal for jets. Also i have decided to take on the task of adjusting the diz curve somewhat to take care of some of unwanted pinging with the gas we have to run here in my area. While I'm gathering the necessary springs etc for that I have decided that to try and run one of these w/o egr will require some custom Diz recurving to run optimum. I would be interested to know of others first hand experience in re-curving one of these distributors to run w/o egr on the gas we have to run these days. I can tell that the centrifugal ADV portion will have to be changed and also the vacuum custom done as well..in order to run the proper advance for power and economy I want to get to W/O EGR. I will say that I am very happy with the performance of this 2.8L w a 1.01 venturi and 44 jets though..at least at my elevation... I LIKE seeing the plugs running clean..and NO smoke....

 

[kimcrwbr1]

You will need different springs or weights in the mech advance to change the curve i wouldnt have a clue where to find the parts maybe out of a 302 dizzy or a 4 cyl. I`m thinking you could possibly drill holes in the weights to slow down the curve or put rubber bumpers to keep total advance down. I dont think you need to worry about damaging the engine it will just run like butt. I would be concerned about running it too lean at WOT you could cook the valves and pistons. The only thing that cools the valves and pistons is the fuel.

 

[John Smith]

actually the upper shaft of a diz is

You will need different springs or weights in the mech advance to change the curve i wouldnt have a clue where to find the parts maybe out of a 302 dizzy or a 4 cyl. I`m thinking you could possibly drill holes in the weights to slow down the curve or put rubber bumpers to keep total advance down. I dont think you need to worry about damaging the engine it will just run like butt. I would be concerned about running it too lean at WOT you could cook the valves and pistons. The only thing that cools the valves and pistons is the fuel.

what i want to experiment with. evidently they came with different advance configs for different diz's so you could tune the curve. I have an extra one to play with so I'm on the hunt for some other ones with even lower numbers (range of advance capability). We'll get there. evidently these egr'd motors come with more advance built into the curve so it has to be reset to run w/o egr. What makes matters worse is the hot passages in the manifold i suspect..but today i can't afford an offy intake so we'll just play it by ear.....then we get to the gas we have to use today...tuning, tuning......

 

[kimcrwbr1]

When I pulled my intake the egr ports in the heads were completely plugged as well as the ports in the intake. I took a screwdriver and a hammer to chip out the carbon to open them up. Have you tried to make the egr work if you apply vacuum to the egr while the engine is idleing the engine should stall if not you probably dont have to worry about the heat in the manifold.

 

[John Smith]

about the distributor curve..

I thought i would include a link to an excellent primer on this process of re-curving.

http://fordmainline.com/2010/08/20/ford-duraspark-recurve/


Also the re-curve spring kit referred to in this article (mr Gasket 925D) is availble form O'Reillys at $3.99..as well as other places..very common..

Other aftermarket Diz rebuilders offer re-curve services..and you can buy one at a few places already re-set to your specs if desired,

Running a Duraspark diz has brought back to me the memories of what it was like to have to tune your ignition to the fuel and elevation. That along with the carb tuning is what makes this experience rewarding in both power and fuel economy. Of course when you "computerize it" (fuel injection or other controls)..it does it automatically for you..When you do it all manually..It takes a little more work to get it right. This work isn't for the average person to do anymore probably but it is rewarding if you take the time...

I know this info may not have interest to some here but since everyone "durasparks" a 2.8L, and then has varying degree of success in making it run ..I really think that setting the proper advance timing with or w/o EGR may be part of the formula for success depending on which diz you end up with after buying a XXX2691 reman no matter where you get it. Anyway..getting up to speed with this for me has been interesting.and helpful in working on another F150 project i have underway...It all applies for these 80's vintage smog/motors...

best wishes for all who do this...and may you fire on all six with the best of power and economy...

 

[drgrcr]

Nice attachment on dist recurve. I have not recurved my dist, I use the total advance method for setting the timing with the vacuum disconnected. The timing is set to 36' at 2800 rpm (that is were the mechanical quit advancing) and have the vacuum adjusted to add an additional 10' at 10" of vacuum. I have not played with the adjusting the timing, I am sure a 10' slot and 2 light springs will make it feel much torquer on the punch.

I did find a MSD 5 module and a adjustable timing module, for those occasional trips to the 600' elevation, it will be nice to retard the timing from the drivers seat...

Getting closer to the engine rebuild. I will post the rebuild with photo's when it happens.

 

[John Smith]

good strategy

Nice attachment on dist recurve. I have not recurved my dist, I use the total advance method for setting the timing with the vacuum disconnected. The timing is set to 36' at 2800 rpm (that is were the mechanical quit advancing) and have the vacuum adjusted to add an additional 10' at 10" of vacuum. I have not played with the adjusting the timing, I am sure a 10' slot and 2 light springs will make it feel much torquer on the punch.

I did find a MSD 5 module and a adjustable timing module, for those occasional trips to the 600' elevation, it will be nice to retard the timing from the drivers seat...

Getting closer to the engine rebuild. I will post the rebuild with photo's when it happens.

I had found one of those older discontinued msd off-board adj units that they no longer make but didn't pull the trigger yet. It is analog I guess making it compatible with any duraspark box not just msd. the new version i guess works with msd boxes just not a regular durspark box.
handy to have though in case you get some bad gas on a road trip..or change elevation drastically...especially if you have your "tune" to optimum for where you normally drive. (which is what we're after )

I haven't pulled mine out yet to DO the tricks..I've been busy with my newly acquired F150 witch I'm working over now the same way...(another story altogether 351w but the same principle applies) but I'll get to it in about 10 days or so.

I will set my initial advance in the following way by Vacuum. advancing till maximum manifold vac at idle then retard 2" HG and use that as the initial set. (presumably about 12") Then like you attempt to get about 20 degrees centrifugal then about 8-10 vacuum on top....

We'll see how well that works with this ethanol gas I have here might have to tweak it all... and of course see how it all works according to any detonation under load...so the search is on for those "10-11" degree -slot upper-shafts. maybe start a collection since these diz's seem to be in my future....good success to you in your "tuning"...

(and to YOU KIMcrwbr1..you could tune the same way should you use the egr..and since detonation is what determines final advance in a given situation..and you tow a boat ..maybe just dial in the full advance a little later in rpm (3500 or so?) by springs tension etc..I'm sure you've got that figured out..)

It is my plan to tune this way so as to get that "gray" tailpipe after a nice run using the smallest jets for elevation operation..THEN we'll see the economy I'm after. Keep in mind this is my grocery getter NOT a mud-bogger that I'm just pouring gas into hoping for the best...(not that there's anything wrong with THAT) (disclaimer)

(Doing a little research reminds me that in the 70's this motor was used in Europe with a Weber variant..and in the US a Mustang II used a Holley/Weber 5200 early in the 70's so it's gettin' plenty of fuel...just needs managed better..(which a good working TFI driven /2150A used to do when it was new..albeit with all it's other bells and whistles hooked up)..

... then if I DO use one of those older MSD retard adjusters..we'd have it ALL set for any gas any road trip etc....

 

[John Smith]

about the distributor re-curve..

I finally got around to pulling apart the 2nd diz i have for the 2.8L in the DD and I see that the mechanical advance weight/spring arrangement is slightly different than in an earlier post-write-up I mentioned at least on this particular XX2691 reman I got from Napa the other day. It seems that although this 2.8L diz shares some similarity with the I-6 family of engines from Ford it may not have the same weight arrangement so tuning is somewhat in new territory. I-6 family of engines though share the same pickup coil NAPA part #ECH MP712 if IIRC and am reading parts numbers correctly..so if your BIG or small I6 FORD (and any 2.0, 2.3L L4)..has a Duraspark IGN..IT may share not only the "blue" module, but also the PU coil plate. Nice info for keeping spares...

But the Weight's for mech adv may be different. The basic principal is that each duraspark DIZ was originally released for "SMOG MOTORS" (EGR, AIR, etc... )..So to tune the advance is critical especially for "around town driving"...may I post some off site info here..

http://classicinlines.com/DSIIswap.asp good reading and informative ..especially the re-curve info...

This reputable website seems to state that MPG CAN be improved by re-curving the diz for conditions. Not surprising to discover since the computer does it so well...but we took since we that out... we must do some thinking and TINKERING to help our vehicles reach the same degree of performance..or at least closer to..what we really are after..

and NO RELAYS or CELS.....

anyway..best success to all who read here...

 

[kimcrwbr1]

Some interesting stuff the thing is the 2.8 is a different animal all together. Must be the german engineering it is not like any strait 6 or v-8 I have ever worked on. I think I`m gonna get a old duraspark to play with I have a welder friend but I like the idea of quick advance off the line and the delay for total advance. Two different spring tensions sound like direction I`m gonna try first and reduce total advance about 4 degrees 10 degrees base with 10 degrees vacuum and 22 degrees mech advance. I wonder why MSD never made a dizzy for the 2.8 it wold be nice just changing the curve electronically.

 

[John Smith]

It's a revealing journey..

Some interesting stuff the thing is the 2.8 is a different animal all together. Must be the german engineering it is not like any strait 6 or v-8 I have ever worked on. I think I`m gonna get a old duraspark to play with I have a welder friend but I like the idea of quick advance off the line and the delay for total advance. Two different spring tensions sound like direction I`m gonna try first and reduce total advance about 4 degrees 10 degrees base with 10 degrees vacuum and 22 degrees mech advance. I wonder why MSD never made a dizzy for the 2.8 it wold be nice just changing the curve electronically.

As I found out..the weights/springs arrangement IS different in the 2.8L diz i have apart right now (I haven't pulled the out of my DD yet). than the general write-up for other Ford diz's it seems. Having torn apart a couple of 2.0, 2.3 diz's I find they ARE the same weight/spring arrangement in the re-curve write-up, albeit the top shafts are different for Cw rotation diz's, and CCW rotation ones...(the top shaft won't interchange from my 351W and a 2.3L for rotation reasons.) I would love to see some examples of weight/spring arrangements of some other Ford diz's..but information may come out about that as research is done. It's hard to imagine that this XX2691 Ford diz weight arrangement ONLY is used in this application but it may be true.

Anyway so tearing apart a few distributors may be how to learn to mix and match the parts to accomplish what we need cheaply. Of course a custom diz shop could tune it I'm sure if one exists nearby.

Of course this Re-incarnation shop IS in Tacoma ....

http://www.reincarnation-automotive.com/index.html

so maybe they would curve it for you..I'm sure they would for a fee of course..maybe not too much...I know I would love to have a distributor machine...spin it up and set it YOUR way.....No-one seems to do this in Southern Oregon it seems...

I believe that Mallory still makes a Diz as well....(dual point) but the cost is up there...and defeats to purpose of running a DSII as easily as adapting what we have...I'm sure we'll get there with better curving info for what we do....

Anyway..carry-on

 

[kimcrwbr1]

I just did some calcs on cfm and the 2.8 takes 227 cfm at 4600 rpm and the 1.08 carb=287 cfm carb. The 1.01 carb=240 cfm so for fuel economy the 1.01 venturi would be a better match for processing the fuel better in my opinion. How is the 1.01 working on your engine are you still running #44 jets. I am sure with the combo between fuel delivery and advance curve I could gain some hp/mpg.

 

[John Smith]

some info..

I am still using the #44 jets. I DO have some advance curve issues that I'm working on since i have a dual vacuum diz still in use. I am still using port vacuum as well. I will use some manifold vacuum again perhaps as soon as I re-drill the hole in the adapter (the welding shop filled ALL the holes at my request..I forgot about leaving one for manifold vacuum..my bad) But all of that aside..I can accelerate, and maintain any road speed i want, I have 3.73's and 215'/75r's and they are meaty bfg m2's. I filled up yesterday to the brim and using the milepost's for re-calibrating my speedo w the tire change...as near as i can tell I went 253 miles using 14.6 gals. (17.32). This includes about 75 miles of freeway driving at approx 55 max the rest around town....as yet i don't have a working choke so i warm it up slowly and use the accel pump to keep it running initially..(I know I can improve all of that. I have plans to do a "hot-air" choke)..

Once I get the stem seals done...I think I could actually use smaller jets. I have a set of 42's..and by playing with the accelerator rod...who knows..
I haven't done any fine tuning with the power valve but I think I put an "9" hg in this carb...

I wish i had a .098 venturi, but I'm very satisfied with this 1.01 I have a couple 1.02 cores as well they seem real common...

But this 2.8L has a lot of power w 44's..and seems to provide plenty of low end pickup..I'm anxious to put the single advance diz in to set the timing a a little closer...It's running well though and I may not get to that for a week or so...

I'm just finishing "durasparking" a new-2-me F150 and building a new carb etc...maybe I'll get it drivable early next week..

 

[kimcrwbr1]

The .98 venturi is a 190 cfm carb not sure how well that would work on the upper end. My problem I think would be finding a 1.01 carb with the kickdown lever on it for the auto tranny. On with the search.

 

[John Smith]

the throttle shafts..

on a 2100 should inter-change...if you find a 1.01...I'll try to hook u up w a throttle shaft...

 

[kimcrwbr1]

My first attempt at getting a 2150 on ebay the first carb the venturi cluster was so corroded it wouldnt come apart without breaking it. The second one the throttle shaft was flopping around and when I started the engine it wouldnt return to idle unless i stopped the engine. The one I`m running now I went to a friend who owns a repair shop and had one on the shelf he gave me go figure.