barnett468

ok pics are good.

i meant where is the other end of your pcv connected to ie.the carb or intake?

front or back?

if intake then which cylinder runner?

it needs to go to the carb. if it is in the intake it will cause a problem. if it is in number 4 runner it might be getting oil to that cylinder or leaning it out to the point it misses.

Are you instantly stomping the gas pedal to the floor during the dead stop acceleration tests or are you easing into it. you need to stomp it to the floor like a drag racer for the test to work.


i also added more to my previous post with more questions.

gear ratio?

cam size, small, medium big?

air filter type.

most likely it is the carbon plug cyl creating the prob but i would still disconnect the msd.

that plug should be replaced.


IGNITION TIMING - Your 20 degrees of mechanical is way too low you absolutely must have at least 28 and 32 is likely max. all in at 2500 - 2800 is good. if someone told you that 20 is what you need they are simply...well, WRONG, LOL, unless you have more than 9.0 of "dynamic" compression [not static compression]. timing 8 degrees you will gain at least 300 rpm.

If you disconnect your vac advance and run your eng at 2500 rpm, and advance your timing 8 degrees you will gain at least 300 rpm. you can actually advance it until it stumbles then back it off around 3 degrees.

this will obviously be too much initial so you need to fix the mechanical portion to achieve this.

you will get more peak rpm, more total hp, quicker acceleration and better gas mileage.

your vacuum advance has no affect on this when you are actually driving.

your plus 10 of vacuum advance is good.

i use ported vac.

Gun Jam

im running 12 initial with 20 adv for 32 all in. The max physical adv I can run 25 period.... and that would put me at 37....that's way too much.

So do you think I should retard my initial timing to 8 and 25 mech adv? I know 100% that if I reduce my base timing from 12 and dont touch curb idle screw idle RPM will sag. I'll gladly give this a shot if you think its a good idea.
I am using ported vac

PCV connects to back of carb

Air filter type is oval element

gear ratio is 380 tru track

when I did the test I got the car rolling pretty quick but smooth like 1 second clutch time and then pretty quick to full power about 1 sec. Im not going to just smash it and dump the clutch that's fairly abusive and would result in massive tire loss and loss of most directional control its also a mech 2nd carb.


cam is mild hydraulic roller....its about 520 thou lift but 218 duration at .050.

barnett468

hi

ok manual trans, ok, yeah you did it right, lol.

ok the pcv is not causing your miss or carbon plug. one more down.

i thought you said you had 20 degrees at 2500 rpm.

if you are at 32 at 2500 then that is close enough.

how do you know 37 is too much, have you tried it?

i have run many at 37 but it is typically the outer limit. i usually go 32 but it depends on the engine build etc.

you are at cruise more than you are at idle so max timing is more important anyway.


the best to try is 12 initial since it works for you then turn it until it stumbles, back it off. see if it pings. it oit diesn;t then modify it so is has 12v initial and the samount of total you gave it. it should be around 12 and 28 - 34 without the vac advance.

Gun Jam

I am running 20 adv at 2500 but that's on top of the 12 initial, Plus an addition 10 deg when vac is above 10 inhg.

I was told never to exceed 35 under load...and 34 was optimal for a 9:1 compression ratio. If I ran 37 I doubt it would ping...but it sounds scary.

I tried using the "knock" method for base timing. They said turn the dizzy at idle until you hear it knock rpm will increase with vac at a certain deg you'll start to hear engine knock, then back it off a few deg and that's your base timing....well I gave up when I went past 30 and it was still purring along.

With 12 initial if Im not careful with the clutch for example I let it out a bit too far too fast it sounds like I get engine knock for an instant.

Do you think reducing base timing would make the clutch more forgiving?

barnett468

HELLO

Ok sorry but the knock method is not the beast and neither is the one i suggested unless you know how to use it and its limitations.

there will be a point where it will quit increasing the rpm at a rapid rate.

in other words. if you have low timing and you turn it 3 degrees, the rpm might jump 200, another 3 degrees and it might jump another 200 another 3 degrees and it might only jump 100, another 3 degrees and it might suddemly only jump 25. this will happen no matter what.

once it quits making "noticeable" increases in rpm, you have reached the limit of benefit you will gain from advancing it and advancing it more will be detrimental.


your timing is fine.

reducing the initial will only have an adverse affect on the clutch/engine if it has any at all.

if you tell me exactly what clutch you hsave and exactly what the problem is, i can likely tell you exactly why you have the prob and how to cure it.

clutch chatters are caused by crummy discs, incorrect finger height on a 3 finger pressure plate, oil on clutch, burnt clutch and flywheel and any zoom clutch, especially the carbon fiber ones.

Gun Jam

Its a Ford racing king cobra 10.5 diaphragm clutch system.

That clutch doesnt like to be feathered it wants to hook up. The only real issue is if you dont keep advancing the throttle as you let the clutch out it will cause something to knock...not sure if its engine ping or clutch chatter but you can hear it and see the shifter handle bounce about.

It would be nice If the throttle to clutch ratio were more forgiving...It seems maybe its become slightly less forgiving but that might be a carb issue or me just getting lazy...its not really an issue at this point more like an observation.

-Gun

barnett468

hello;

ok unfortunately if you bought it off ebay, it is likely chinese. there are hundreds of fake chinese cobra kits on ebay. if this is the case then the whole thing is less than optimal.

it should release as smooth as glass. yours is chattering. your engine might be pinging at the same time.

if you install a mcleod series 100 clutch disc, lt will cure the prob guaranteed.

Gun Jam

Plug 1 and 4 are richer than the rest....

#1 looks like its in the "Ideal" range

#4 has improved since I last looked at it looks to like its in the "rich ok" to rich range it does not have the dry black soot on it to a degree that the plug color is black.

the other plugs look fairly close to each other

barnett468

hello

what is the number on the plugs?

it looks like 3926

you need 3924 or 3923.

if you have 3926 and someone told you to put them in there, they can buy you a new engine if it eats a hole in a piston.

those plugs are trash also you need new ones.

your plug chart is inaccurate. all your plugs should look exactly like number 1 plug or between number 1 and number 4. you have a high perf non computer controlled non fuel injection car. only computer fuel injection plugs should look nearly white or lite gray. your engine is thirsty.


no other explanation for the one dark plug unless some vacuum source is plugged into that intake runner.

i would still swap that plug wire or put one on from another car to see if the miss goes away.

number 7 is about to melt your piston

the lighter plugs are lean. this is why afr meters are basically useless.


Go up 1 size on the mains also.

also, turn your idle up to 1200 and set your fuel mix screws equally until you reach highest idle. then reduce idle speed.

tell me if the idle speed increased when you moved them.
.

Gun Jam

They are 3924 should I go down a heat range? If that plug were too hot wouldn't I get engine knock or the plug show signs of electrode wear?

Ill try swapping the plug wire as well.