Re: When is it time to try locking out the distributer?
[Re: Quicktree]
#1478710
08/03/13 06:58 AM
08/03/13 06:58 AM
|
Joined: Jan 2003
Posts: 10,011 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,011
Frostbitefalls MN (Rocky&Bullw...
|
When the cam duration gets real long the idle vacuum is so low it needs the full timing (or will tolerate it!) to idle properly. Th lower the idle vacuum, the lower the idle cylinder pressure at TDC, hence the need for more idle timing. Low cylinder pressure means a slow burn. If you have 260 degrees at .050 or more, try full advance and see. Less than that, I am not sure. It would depend on the intake closing point.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
|
|
|
Re: When is it time to try locking out the distributer?
[Re: gregsdart]
#1478711
08/03/13 08:18 AM
08/03/13 08:18 AM
|
Joined: Jan 2003
Posts: 8,028 Tulsa OK
Bad340fish
master
|
master
Joined: Jan 2003
Posts: 8,028
Tulsa OK
|
My cam is 258@.050 and it loves the timing locked out. One thing I have noticed since I locked the timing out is that when warm it always starts like its fuel injected, tap the button and its alive.
68 Barracuda Formula S 340
|
|
|
Re: When is it time to try locking out the distributer?
[Re: Bad340fish]
#1478712
08/03/13 09:22 AM
08/03/13 09:22 AM
|
Joined: May 2004
Posts: 12,397 Taxes & Virus's R-US, NY
Dragula
OP
I Live Here
|
OP
I Live Here
Joined: May 2004
Posts: 12,397
Taxes & Virus's R-US, NY
|
My current cam is 260° at .050" on intake and 268° at .050" on exhaust...I already had to shorten the throw on the mechanical advance to add timing at idle to get it to idle better, but it seems like it wants more yet....right now I have it at 15° at idle, 35° total. Just seems a little lazy, but I am used to injection too....I was thinking of shortening up the mechanical advance some more, but wondered, if its that short, why not just lock it out...
|
|
|
Re: When is it time to try locking out the distributer?
[Re: MR_P_BODY]
#1478714
08/03/13 10:30 AM
08/03/13 10:30 AM
|
Joined: Oct 2003
Posts: 614 ont,canada
mopartuner
mopar
|
mopar
Joined: Oct 2003
Posts: 614
ont,canada
|
Does the compression or fuel you run have a bearing on this?My cam is 262/274 @ .050 and I run 94 oct pump fuel,does this make a difference?I am having a bit of an issue getting a clean idle and starting it.
410 pump gas solis flat tappet cam 10.95 so far
|
|
|
Re: When is it time to try locking out the distributer?
[Re: mopartuner]
#1478715
08/03/13 10:38 AM
08/03/13 10:38 AM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Quote:
Does the compression or fuel you run have a bearing on this?My cam is 262/274 @ .050 and I run 94 oct pump fuel,does this make a difference?I am having a bit of an issue getting a clean idle and starting it.
Whats your set up now... the dist in my Rampage is locked at 40* right now and when its warn its a bit to much... that dist we put in it on the dyno but I am changing it to use advance (this is on a 416).. the cam is 260/270 and was running 93 octane with 10.6 compression... higher compression does have a effect on it.. the more compression the more it wants to kick back
|
|
|
Re: When is it time to try locking out the distributer?
[Re: MR_P_BODY]
#1478716
08/03/13 10:50 AM
08/03/13 10:50 AM
|
Joined: Jan 2007
Posts: 3,695 nc
emarine01
master
|
master
Joined: Jan 2007
Posts: 3,695
nc
|
I also think once your duration gets up to the 260s.@.050 locking out is fine, We run 32 to 34 locked depends on the fuel and air temps, If you run a hi stall converter a curved dist is not necessary, a timing retard may be needed on hi compression 14+, ya have to play with it and see what it likes.
|
|
|
Re: When is it time to try locking out the distributer?
[Re: MR_P_BODY]
#1478717
08/03/13 10:54 AM
08/03/13 10:54 AM
|
Joined: Oct 2003
Posts: 614 ont,canada
mopartuner
mopar
|
mopar
Joined: Oct 2003
Posts: 614
ont,canada
|
I am only giving it 14 deg at idle/32 deg total.I want to keep the timing down a bit,my last build showed signs of detonation.I run an MSD pro billet dizzy with the largest bushing and the lightest spring.18 degree swing with the black bushing.The cam is installed at 104 cl .
410 pump gas solis flat tappet cam 10.95 so far
|
|
|
Re: When is it time to try locking out the distributer?
[Re: mopartuner]
#1478718
08/03/13 11:02 AM
08/03/13 11:02 AM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Quote:
I am only giving it 14 deg at idle/32 deg total.I want to keep the timing down a bit,my last build showed signs of detonation.I run an MSD pro billet dizzy with the largest bushing and the lightest spring.18 degree swing with the black bushing.The cam is installed at 104 cl .
Thats low base timing for a cam that big... I would think you would be closer to 20* base and limit the total to what you need
|
|
|
Re: When is it time to try locking out the distributer?
[Re: mopartuner]
#1478719
08/03/13 11:04 AM
08/03/13 11:04 AM
|
Joined: Feb 2003
Posts: 1,646 Ontario,Canada
firefighter3931
top fuel
|
top fuel
Joined: Feb 2003
Posts: 1,646
Ontario,Canada
|
Quote:
I am only giving it 14 deg at idle/32 deg total.I want to keep the timing down a bit,my last build showed signs of detonation.I run an MSD pro billet dizzy with the largest bushing and the lightest spring.18 degree swing with the black bushing.The cam is installed at 104 cl .
Bob, that's a lot of cam with pump gas compression. My old 446 started and ran fine with a 264@.050 solid and i locked the distributor out and timed it at 35*.
Same deal with the 572 i have in there now ; pump gas compression and big solid roller. Starts and idles fine...even warm with the dizzy locked out at 35*
As long as it doesn't kick back i'd say lock it out
Ron
|
|
|
Re: When is it time to try locking out the distributer?
[Re: firefighter3931]
#1478720
08/03/13 11:15 AM
08/03/13 11:15 AM
|
Joined: Oct 2003
Posts: 614 ont,canada
mopartuner
mopar
|
mopar
Joined: Oct 2003
Posts: 614
ont,canada
|
I think I will lock it out,Thanks for chimming in guys,didnt mean to hi-jack........alot of issues with this new build,
410 pump gas solis flat tappet cam 10.95 so far
|
|
|
Re: When is it time to try locking out the distributer?
[Re: MR_P_BODY]
#1478723
08/03/13 01:44 PM
08/03/13 01:44 PM
|
Joined: Oct 2003
Posts: 7,143 my own world
theraif
master
|
master
Joined: Oct 2003
Posts: 7,143
my own world
|
Quote:
Quote:
Gots few passes on the old Hemi this year, and it still seems a little lazy at the hit...When do you guys decide to try it and why? Do I need a start retard?
I dont like to lock them out unless you keep advancing the timing to have it idle right and that point is in the 25* area... then its less than 10* of total advance... I like to curve the dist so it starts nice and advances to its total at about 1500-1800rpm EDIT you just dont want the start of the advance point to be at the same rpm that you idle at.. that will cause hassles when trying to get it to idle
that the set up we have full advance @1400 rpm
|
|
|
Re: When is it time to try locking out the distributer?
[Re: Bad340fish]
#1478725
08/03/13 06:20 PM
08/03/13 06:20 PM
|
Joined: Jan 2003
Posts: 6,266 Renton Washington
Triple Threat
master
|
master
Joined: Jan 2003
Posts: 6,266
Renton Washington
|
My old motor was 11.3:1 263/268@.050 and I ran it not locked out, 25 at idle, 35 total. Pump gas. It still wanted more at idle but it ran fine.
New motor is locked out. 12.3:1, NO start retard. 36 degrees 24/7 on E85
Looking back, I should have locked the timing on my old motor as well, throttle response is much better, and they roar to life easier.
-Dustin 67 Dart, 9 second, 392" G3 Hemi 68 Barracuda 340 F/SA
|
|
|
|
|