Demon NO Go

[Grinder]

You will be very happy when she is tip top. Having a 6 pack is bad ***! I have always wanted a 340 6 pack a body.

DEFINATELY put a vaccum guage on there,no matter what the problem. Its one of the best tools you can have for tuning.Lets us know what you find...

 

[6pk2goDemon]

You will be very happy when she is tip top. Having a 6 pack is bad ***! I have always wanted a 340 6 pack a body.

DEFINATELY put a vaccum guage on there,no matter what the problem. Its one of the best tools you can have for tuning.Lets us know what you find...

Hope your first sentence comes true for me and you. It does look "bad ***", but chrome don't get ya home huh.....LOL

Have not worked with a vacuum gauge before, but willing to learn and ask questions.

Thank you very much for your help Grinder and all that have posted. It is much appreciated......:-D

 

[Grinder]

It will it will!!! But if you get her running good,you owe me a ride in her when our paths cross!

Now get a vacuum guage and get'er done!:-D

 

[6pk2goDemon]

First things first, I think you need to install a pressure guage just upstream of the carbs and verify that you are running no higher that 8psi and I would prefer 7psi. You can buy a cheap holley fuel regulator that has 1 inlet port and 2 outlet ports and install the guage on one of the outlet ports.
Terry

Terry....Did I remember to say I love cars...LOL

Have a regulator, but don't want to hack up the fuel line again if not necessary. Was hoping the holley red would be a streetable "no fuss" pump.

I'll let you know when issue is resolved. Thanks again for your help. :happy10:

This car is trying my patience to say the least. ale:

 

[Babyblue66]

Whats your initial timing set at?

 

[6pk2goDemon]

Whats your initial timing set at?

Pretty sure it's @ 8 degrees.

 

[demon seed]

Don't worry, if this group can't figure it out then we all need to go back to school. Has that regulator got an extra port that you can plug in a pressure guage to and try setting your initial timing to 12-14 deg. for a start and make sure your vacuum line is unplugged from the dizzy and the line itself is plugged if ya haven't allready.

Terry

 

[6pk2goDemon]

Don't worry, if this group can't figure it out then we all need to go back to school. Has that regulator got an extra port that you can plug in a pressure guage to and try setting your initial timing to 12-14 deg. for a start and make sure your vacuum line is unplugged from the dizzy and the line itself is plugged if ya haven't allready.

Terry

Keeping the spirits high and looking forward to the day the Demon runs again.....It's been about 9 years :clock:


If it would just cooperate and run long enough......:hmph:

Have never had this many problems before and I think we are overthinking, extremely frustrated and extra cautious......soooooo many weird & stupid issues that have snowballed. I am sure this Demon is possessed....LOL

Regulator has 1 port in and 2 out........Dizzy is unplugged and line is plugged.

 

[Longgone]

Do you really need an electric fuel pump and a regulator for your carb set-up? If your 5/16ths fuel line is clean then you should have have ample fuel supply to your carbs ,even at WTO. If you have an eccentric on your cam ,I say go to NAPA and buy a Carter mechanical pump for $30.00. Slap it on there and plumb your fuel lines to your carbs. It sounds like your idle circuit is not getting in on the act. The outboard carbs can be set a little richer (1/4 -1/2 turn more) than the factory spec to help with idle issues. Try bumping up your timing to around 12 before (or more if needed) to increase your idle speed. Check your float level once you get it started and idling. You might check your plugs again too because they might need cleaning after running rich. Good luck, I hope you get it figured out soon.

 

[waggin]

keep the faith your gonna git this demon to live up to it's name soon enough,you can do it girl we got faith in ya!!!better give er that pat on the dash and a good stern talkin too!!! send member Pfogal a pm,hes a great friend of mine and knows carburetors like the back of his hand.it sounds like the wrong power valve for the camshaft you are running or a problem in one of the metering blocks.I'll talk with him and see about getting you his number or have him give you a call and definately sounds like it needs a little more timing,should have anywhere from 32 to 36 degrees total timing with a smallblock,get a timing lite with the dial so you can see where it is and where it cleans up....wish I was there to help.don't forget the pat on the dash!!and just to be on the safe side pulll the dipstick and make sure it doesnt smell like gasoline,recheck the valve adjustment,float level can be set without the engine running but should be rechecked with it running,I'll get with my dawg pat tomorrow and see what he says so give a holler if ya need.

 

[moper]

Have you verified the firing order? Sounds dumb, but I still get 5 and 7 backwards once in a while. Tell me more about the engine... How new is new, was it ever run before? What cam? details please... It does not sound like any carb issue to me.

 

[pettybludart]

I,m with Waggin on the timing,8 seems low.Bump it up to 12 at 32-34 total,give that a try and reply with your outcome.That,s where my 340 is set,no 6 pack though.

 

['64 Cuda]

Did you put a check ball in your center carb to keep the power valve from blowing when you have a backfire?

And I agree that you might need a little more than 8 degrees on your initial timing.

 

[ramcharger]

Yep, 12-14 degress initial. Whats your cam specs?

 

[slim 67]

Vac reading depends on your motor/cam specs. But what you are looking for is an irregular reading.If the needle bounces around its either a vac leak or jumping time. If I remember correctly the 6 packs primary carb is the center carb correct? Run the guage on a vac port of the center carb,and report back what you find.

Have you set the timing? do you tune your own carbs? Let us know what the timing is set at,and how rich you had to tune the carbs. If it wont idle below 1500 with the throttle plate open 1/8 inch,sounds like you have a leak and you have to run rich to compensate for the extra air running into the engine. Who installed the manifold? Who rebuilt the carbs?

May I ask what you mean by "jumping time" when you describe an irregular reading on a vac. gauge? Last time I hook up my gauge the needle was just a blur that looked like it was about a half inch wide. Thanks!

 

[6pk2goDemon]

:notworth: :salut::salut:

Can you say information overload.........LOL

Thank you all for your input. Here is a little summary of the build.

72 340 block freshly bored .30 over
8.5 to 1 TRW forged pistons (New)
2.02 / 1.60 valves in J heads w/ fresh valve job
Hydraulic Cam is very close to stock 340....can't remember specs...duh
Stock Exhaust Manifolds

Using a gear drive, so cannot use a mech pump. Never would have gone w/ this decision if I knew how much trouble this would be. :banghead:

Mopar Perf 6-pk intake w/ 3 POS carbs on top :violent1:


This was gonna be my Christmas present, but maybe it was for 2009 :tongue3:. Sooooo close, but just discouraged. It'll get there.......:cheers:

Will get back on it sometime this week. Have to figure out which suggestions to try in which order so as not to change toooooo many things at once.

I know this is NOT rocket science, but it sure is acting like it !!!!

 

[340demon]

Hey 6pk you said this is a new motor have you had it running long enough to break the cam in if not you NEED to do that first or the cam may go flat. then the motor should be warmed up and you should be able to set the idle and timming if it is a fuel pump problem it should be leaking fuel from the two other carbs you said it had not run long enough to get warm that is why i ask this just slow down a little and do not panic I think you are fine there are a lot of adjustment that you will need to do to fine tune this old school engine we are all here to help

 

[6pk2goDemon]

Hey 6pk you said this is a new motor have you had it running long enough to break the cam in if not you NEED to do that first or the cam may go flat. then the motor should be warmed up and you should be able to set the idle and timming if it is a fuel pump problem it should be leaking fuel from the two other carbs you said it had not run long enough to get warm that is why i ask this just slow down a little and do not panic I think you are fine there are a lot of adjustment that you will need to do to fine tune this old school engine we are all here to help

Broke in the motor a month or so ago. Got it up to temp, set the timing, etc. About 20 minutes of run time total.

Which reminds me that's when the tiny crack in the oil pan was found. I forgot about that little Demon problem. :angry7:

No fuel leaking from the outboard carbs during break-in or now.

No panic at all.......extreme frustration though. As I mentioned, been trying to get this thing going since Nov. Thank you for your input.

 

[340demon]

YEP know about the DEMON thing a job I thought would take 6 to 8 weeks has been going on for 9 mo. now just got it on the road last week look at my post drove it today for pict. I had to take the pan off 4 times and the intake 2 times had header leaks so the were on and off 3 times now the fine tunning starts think will need to change gear ratio or the cam may have too much cam

 

[340sixpack]

I agree with the others you need to get the timing on first.I messed with my carbs on mine for a year come to find out the MSD was screwed.After that
they all worked well with some minor tuning.Hook your vaccuum on the drivers
side rear of the manifold,probably a plug there now, remove that and get a
barbed nipple.

Heres some good references for tuning.

http://www.mopar1.us/6barreltips.html

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=4244196&an=0&page=0#Post4244196

See Daclona

http://www.moparts.org/Tech/Archive/fuel/7.html

Pay no attention to the 440,same thing needs to be done to the 340 just different jettings,pv,etc.Good luck!!!!!!!!!!!!!

 

[Grinder]

May I ask what you mean by "jumping time" when you describe an irregular reading on a vac. gauge? Last time I hook up my gauge the needle was just a blur that looked like it was about a half inch wide. Thanks!

Jumping time is when you have too much slack in your timeing chain or gears,and it 'jumps' around.

 

[pettybludart]

6pk2goDemon,I talk to a carb.friend of mine today,and he said if you getting flooding in your center carb that your bowl is flooding from the pin stuck open.There could be dirt jamming it.Just thought I would mention it.Good Luck!My friend rebuilds # matching BB carbs for any make,and he really knows his stuff.

 

[6pk2goDemon]

Thank you for the links 340sixpack. I actually had 2 of those in my favs already and added the 3rd. I've been doing alot of reading today.


I think as others have suggested, will try to bump up the timing a bit first. Sounds like 12 - 14 initial is what is needed.

Maybe vacuum gauge as the 2nd step ???


Thanks for the tip pettyblu....I assume by "pin stuck open" that he is referring to the needle and seat. Have had all 3 carbs off and on and off and on. You get the picture......:homework:

 

[moper]

What intake and carb was used to break it in?

 

[6pk2goDemon]

Have you verified the firing order? Sounds dumb, but I still get 5 and 7 backwards once in a while. Tell me more about the engine... How new is new, was it ever run before? What cam? details please... It does not sound like any carb issue to me.

What intake and carb was used to break it in?

1 8 4 3 6 5 7 2 clockwise.....checked this enough times that I know it by heart.

6 pk intake and carbs were used for the break in.