[cobalt327]

Originally Posted by red65mustang

blue,,,

grrrrrr....

stupid in-complete Accel instructions tripped us all up on vacuum advance!!!

the "brochure" states your 71100 series dist has a "vacuum advance lock out feature" to run mechanical only

the old vac unit and new vac unit are not adding timing because it is engaged

scroll down to the 71100 details:

http://go.mrgasket.com/pdf/ACCELdistributors.pdf

I wasn't able to link the site, I'll try later- but does this mean that w/a change, the dist. vacuum advance will now work (I hope)?

There must be a genetic thing w/guys and instruction sheets! lol

[Frisco]

Originally Posted by cobalt327

I wasn't able to link the site, I'll try later- but does this mean that w/a change, the dist. vacuum advance will now work (I hope)?

I just read the specs on the link. Shows a factory built in 24 degrees of mechanical advance and the return spring/weights are set so that the mechanical begins at 1200 RPM and max out at 3000 RPM. Also states that the preset vacuum advance is at 10 degrees.

Blue should understand that he can change these settings by swapping out the return springs for lighter ones.

When the lockout feature is removed/disabled, Blue should be able to set the Total Mechanical timing to 38 degrees. This should yield an initial of 14 degrees. With the vacuum cannister adjusted to yield an additional 10 degrees, he should be somewhat in the ballpark. I do think that he should try those settings. If not satisfied then he should consider limiting the mechanical advance to 20 degrees so that he can increase the initial timing to 18 degrees without increasing the max mechanical timing of 38 degrees.

The lockout feature is nice if the engine is for drag only. Should be removed/disconnected for street use.

Originally Posted by cobalt327

There must be a genetic thing w/guys and instruction sheets! lol

YUP! I never read the instructions until I find out whatever I've done didn't work. When all else fails...READ the instructions. LOL

[red65mustang]

Frisco
I re-wrote that last #195 post above,,,please re-read...

blue tested the original vac unit with help from us and we thought it was dead...

he has just mounted a new correct replacement vac adv unit

(and it could be causing the centrifugal hang etc)

[cobalt327]

Originally Posted by Frisco

I just read the specs on the link. Shows a factory built in 24 degrees of mechanical advance and the return spring/weights are set so that the mechanical begins at 1200 RPM and max out at 3000 RPM. Also states that the preset vacuum advance is at 10 degrees.

Blue should understand that he can change these settings by swapping out the return springs for lighter ones.

When the lockout feature is removed/disabled, Blue should be able to set the Total Mechanical timing to 38 degrees. This should yield an initial of 14 degrees. With the vacuum cannister adjusted to yield an additional 10 degrees, he should be somewhat in the ballpark. I do think that he should try those settings. If not satisfied then he should consider limiting the mechanical advance to 20 degrees so that he can increase the initial timing to 18 degrees without increasing the max mechanical timing of 38 degrees.

The lockout feature is nice if the engine is for drag only. Should be removed/disconnected for street use.



YUP! I never read the instructions until I find out whatever I've done didn't work. When all else fails...READ the instructions. LOL

Got to see the link.

It sounds to me like the "insert" used to lock out the vacuum advance for racing/huge cam, etc. would take the place of the vac. advance can, so both the lock out AND the can wouldn't be installed simultaneously.

What I was hoping, was that the lock out could be engaged w/the vac. can still installed in the distributor, and this was causing the lack of the correct amount of vac. advance.

Somehow, I don't think this is the case.

But Blue, have you been able to tell if the vac. can retracts when vac. is applied?

[red65mustang]

cobalt,
I changed #195 to the dist instructions pdf,,,see if that one opens for you...

the first link was just the brochure info which is covered in the instructions...

and here's a different link to the brochure

http://gatorperformance.com/catalog_...stributors.pdf

[Frisco]

Originally Posted by cobalt327

It sounds to me like the "insert" used to lock out the vacuum advance for racing/huge cam, etc. would take the place of the vac. advance can, so both the lock out AND the can wouldn't be installed simultaneously.

What I was hoping, was that the lock out could be engaged w/the vac. can still installed in the distributor, and this was causing the lack of the correct amount of vac. advance.

Somehow, I don't think this is the case.

But Blue, have you been able to tell if the vac. can retracts when vac. is applied?

I looked at and saved both links for reference .

Link 1


LINK2


I agree that according to what I read, the lockout replaces the vacuum cannister and both can not be in place at the same time.

Something is amiss. I remember reading that BLUE and his mechanic have both worked on this distributor and that the original vacuum cannister was swapped out for another. Got to be something limiting the travel of the vacuum advance linkage.

I just looked at the third link.

Link3

This one states that the mechanical curve has a range of 28 degrees and is adjustable in one (1) degree increments. It doesn't say how this adjustment is done.

[cobalt327]

Originally Posted by Frisco

I agree that according to what I read, the lockout replaces the vacuum cannister and both can not be in place at the same time.

Something is amiss. I remember reading that BLUE and his mechanic have both worked on this distributor and that the original vacuum cannister was swapped out for another. Got to be something limiting the travel of the vacuum advance linkage.

GOT to be- maybe the screw(s) that secure the module are too long, or a wire is hanging it up from turning- but something's going on.

I'd like to see what it was doing w/the cap off and vac. applied...

Red, thanks for supplying the links. The prob. was on my end the first time.

I just looked at the third link.

This one states that the mechanical curve has a range of 28 degrees and is adjustable in one (1) degree increments. It doesn't say how this adjustment is done.

That's a good feature. I'm guessing that there's a dial or something like that, to have such a fine adjustment. Bushings, etc. wouldn't provide that small of a change, I don't think. Plus you'd need dozens of them!

[red65mustang]

don't actually know but:

probably adjustable in one "dist" degree increments to 28 crank degrees????

I have a ancient Accel 34000 series instructions sheet in front of me and there are 10,11,12,13,14,+ "dist" degrees holes/screw/plates combo choices....

Frisco,
thanks again,,,I missed the 28c "possible" on the brochure info

[Blue84JeepCJ7]

Originally Posted by Frisco

When watching the timing curve as the RPM increases, the timing should show a gradual increase as the RPM is increased. You stated that it "JUMPS". This is an indication that the advance plate is sticking.

True...my bad, it doesn't jump, just advances quick from 12 to 16 within a few hundred RPM. More on that below!!!

Assuming that those readings are with the vacuum advance dis-connected and plugged, you are showing a built in mechanical advance of 27 degrees (39-12). I don't know of any distributor that incorporates that much mechanical advance. Most GM's are limited to 20 degrees. There are some distributors that have 24 degrees.

This one is suppose to be 24deg mech.

To get the spread reduced between the initial and the full mechanical advance you will have to limit the amount of travel of the mechanical advance plate. This can be accomplished either with small bushings in the slots or by shortening the length of the slots by welding them up. Doing this will enable you to get the initial up to a more desirable 18 degrees while limiting the total mechanical to 36-38 degrees. Once again, the "all in" @whatever RPM is controlled by the return springs and/or the weight of the advance weights. It is very common to get an acceptable reading by swapping out the return springs. The springs can be mis-matched as well. i.e. I have found that one light spring and one medium spring will work well in a GM HEI to keep the "all in" RPM close to the often desired 2600 RPM figure. Going to the 3000 RPM figure is Ok, but is a little high in my opinion for max power under typical street driving condition. A lot will depend on your typical cruise RPM's as to what the "all in" RPM should work best.

Thats a bit much for me right now as the Jeep is my daily driver. I'd like to do that but its gonna have to wait.

Read the adjusting instructions for the vacuum advance cannister. Set the cannister to the max for your initial adjustment. Check how much you actually get at idle RPM. If greater than 10-12 degrees, adjust accordingly.

If you are still limited to 2 degrees, I think you will find that there is something binding or restricting the advance mechanism.

Yeah, I am sure I am the problem....lol The vac adv is adjusted with a hex screw. I was able to get movement at 5" of vacuum, up to 10" of vacuum by adjusting the screw while testing it before installation. I need to check and make sure it is not obstructed on the inside after I installed the cap.


Today I paid a bit better attention to what I thought to be a hesitation. It still could be depending on how you feel it or hear it. Anyway, from a stop with acceleration, as the RPM reaches 1,200, its like hitting the nitros bottle....lol Its as if the 12deg is too low and the 16 kicks in a bit more abrupt than it should. Kinda why I said "jump" in the first quote above. I am just having a dificult time discribing some of this properly!!!

Thanks Guys!! It does run better now but I do get dieseling from time to time. Never had that before. I'll give it a few days untill I can check on the vac adv again!

[red65mustang]

your explaination is ok...

at 1200 is where the carb is transitioning over to the primaries circuit....

quite common that changing the base means changing the carb accelerator pump shot (the linkage arm with 3 holes on the front) is needed (for more or less gas during transition)....

LOL,,,those little spring wire linkage clips have a nasty habit of going "ping" off the needle nose pliers and gone forever so use care removing them!!!!

my $.02:
again, Edie is better suited for a mild cam application and you are (almost) off the low rpms tuning chart with the big cam and low CR combo

[cobalt327]

Too bad the cam specs aren't known, but if Blue's able to get an idle at 800 RPM in Drive, I doubt it's all that "big".

I'm personally MUCH more inclined to believe there is a glitch in the timing delivery, rather than fuel delivery/transition.

No?

[red65mustang]

cobalt,

I'm only saying "big cam" to describe how the jeep is behaving overall....

he's not in the power band for the cam from a stop sign or at cruise due to the stock convertor/gears/tires/CR,,,,, (8-10Hg showing at steady 55mph is yuch)...(basically no low rpm flywheel TQ guts at all)

comp 350 dyno charts link I posted says a 268 is 15.5Hg at 800 no load with 9.25CR/holley 600/performer intake (and that would be with 14-16 base)...
his 14Hg max idle in park at 800 with 16 base at 8.5CR/600Edie/EPS says to me it is about a 268 and maybe the ding bat installed it way retarded raising the TQ rpms minumum (heck if I know)....

do agree,
because the dist has been messed with now atleast 4 times during this thread the cent adv is "suspect"...
(Frisco is addressing that so I added pump shot info for a stop sign condition)

ps: he did say 993 heads way back on the thread but then changed it later,,,,this thread has gotten to be way way to long....

[cobalt327]

Originally Posted by red65mustang

cobalt,

I'm only saying "big cam" to describe how the jeep is behaving overall....

Got a chuckle when I read that- I recently recommended (tongue in cheek) that a guy- who wanted a bad-A sounding engine- instead build his engine correctly for his gears, CR, etc.

Then- when he wanted it to lope, stop a block from Steak & Shake, retard the ignition and pull a plug wire.

Instant 'lope'. lol

[Blue84JeepCJ7]

Originally Posted by cobalt327

Got a chuckle when I read that- I recently recommended (tongue in cheek) that a guy- who wanted a bad-A sounding engine- instead build his engine correctly for his gears, CR, etc.

Then- when he wanted it to lope, stop a block from Steak & Shake, retard the ignition and pull a plug wire.

Instant 'lope'. lol

LOL, I must say I do like the lope sound although mine no longer does this. Why do I like it? Well it all started many many years ago when my dad owned radial engine powered airplane. The design of the engine alone sounds the same as a loping 350. Oh, as well as Harley's! I guess its what we grow up around that we take a lik'en to huh?

Here is an example: http://www.youtube.com/watch?v=FlNN_ZZ3Ffc

[red65mustang]

blue,
"keep the faith!!!!"
once the dist timing is sorted out and the vac adv is working (which will boost idle Hg a bunch) you will have a huge tuning window to tune in "some" idle "bad boy" sound (and still have very good A/F "atomization" at idle) ...

"independent/seperate" Edie idle circuit = you can play with it and not mess up the performance tuning on the primaries and secondaries circuits...

"idle is just idle" on a Edie!!!

(LOL,,,ONLY because my grandkids absolutely love the sound from the exhaust on my car,,,my only a RV cam/Edie 1406 carb is tuned to sound like a "bad boy" note out the exhaust at idle,,,while showing rock steady 18Hg at 700 idle)

repeat a test please:
(my post:you don't know that the dist is still set up in original factory tune up,,,24c max and all in at only 3k)

check to see what the base is set at very low idle rpms (my stupid mistake way back not telling you to do that!!!),,,,then read the total at steady 4500rpms...

it can't be 40t-24c=16b "and" 39t-27c=12b which you have posted,,,
hate to guess but when you set it to 39 it did not stay there,,,it got nudged to 36t while tightening,,,36-24=12 is most likely

or it does have very strong advance springs so the timing is not in till much higher rpms which "could be" to prevent ping