Carb Spacer, idle, cam questions, Sniper
#1
Gold Member

Thread Starter

Just had some new carbs built and unfortunately they weren’t perfect out of the box so I’m experimenting. I tried to switch to 4150’s but they were insistent they could make new dominators work. I’ve adjusted them some but at this point not happy that my idle speed is 900-950 and they still stall out if you aren’t quick on the throttles even if you richen up on the corners a bunch!
565’s,
CAM specs are 264/270, .445/.445 114 LC
im going to experiment tomorrow, but does anyone have thoughts on whether the spacer could be causing me to lose Signal at idle? What about exacerbating a lean problem with more plenum volume?
any thoughts on how much the secondary idle screw should be opened? I’ve been told that opening that at the same rate as the primary can actually cause a lean condition so adjust idle speed exclusively on the primary Side.
would the Holley sniper system Solve my problems? I was going to head that direction but ran out of time to have bungs welded in and switch to electric fuel pumps. Is it smart enough to manage the idle in and out of gear?
565’s,
CAM specs are 264/270, .445/.445 114 LC
im going to experiment tomorrow, but does anyone have thoughts on whether the spacer could be causing me to lose Signal at idle? What about exacerbating a lean problem with more plenum volume?
any thoughts on how much the secondary idle screw should be opened? I’ve been told that opening that at the same rate as the primary can actually cause a lean condition so adjust idle speed exclusively on the primary Side.
would the Holley sniper system Solve my problems? I was going to head that direction but ran out of time to have bungs welded in and switch to electric fuel pumps. Is it smart enough to manage the idle in and out of gear?
#2
Registered
iTrader: (3)

being a four corner idle system you do need to open both front&back barrels evenly,if you leave the secondary closed it won,t idle worth a darn.if this is a new gen3 dominator it has an air bleed that is adjustible by turning a screw under where the air cleaner stud goes.the instructions that come with a gen 3 dominator carb cover it pretty clearly.
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SB (07-01-2020)
#4
Gold Member

Thread Starter

being a four corner idle system you do need to open both front&back barrels evenly,if you leave the secondary closed it won,t idle worth a darn.if this is a new gen3 dominator it has an air bleed that is adjustible by turning a screw under where the air cleaner stud goes.the instructions that come with a gen 3 dominator carb cover it pretty clearly.
Dan - i was going to reach out to you on the snipers. I’ve followed your threads on it (including the recent surge thread). I think this is the way to go, but wanted to salvage my early summer so went fresh carb route.....
#5
Registered
iTrader: (1)

I can understand that .
I`m running the terminator stealth, makes install easier because all my throttle linkages stayed the same.
Plus external ecu.. I believe the Sniper is internal?
They do make a 4500 series Sniper Stealth that supports a ton of power .
Holley has a ton of ways to skin that cat .
Since tuning I`ve never had an engine die on me while shifting , even in 46* weather with almost no warm up .
I`m running the terminator stealth, makes install easier because all my throttle linkages stayed the same.
Plus external ecu.. I believe the Sniper is internal?
They do make a 4500 series Sniper Stealth that supports a ton of power .
Holley has a ton of ways to skin that cat .
Since tuning I`ve never had an engine die on me while shifting , even in 46* weather with almost no warm up .
#6
Registered
iTrader: (1)

They are brand new. I’ll go online and find instructions on the air bleed. Any thoughts on spacer mike?
Dan - i was going to reach out to you on the snipers. I’ve followed your threads on it (including the recent surge thread). I think this is the way to go, but wanted to salvage my early summer so went fresh carb route.....
Dan - i was going to reach out to you on the snipers. I’ve followed your threads on it (including the recent surge thread). I think this is the way to go, but wanted to salvage my early summer so went fresh carb route.....
You have enough initial advance ?
Mike Tkach provided good info above.
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articfriends (07-04-2020)
#8
Gold Member

Thread Starter

So, I just pulled it off and rechecked where I’m at.
A. Disappointed that I bought brand new carbs and they don’t have the idle bypass feature. Weird.
B. I’ve got disparity between the front idle screw and rear, but the primary butterflies are open far enough that a lot of light is coming through. Maybe close to 1/16”.
C. From below it doesn’t even appear that the transfer slots are even exposed (trying to baseline the 0.02 slot square). So when I open the idle speed up its as if it immediately exposes the entire slot.
ill go back out in between conference calls.
fbc - now I’m not so certain that they aren’t pulling too much fuel.......
A. Disappointed that I bought brand new carbs and they don’t have the idle bypass feature. Weird.
B. I’ve got disparity between the front idle screw and rear, but the primary butterflies are open far enough that a lot of light is coming through. Maybe close to 1/16”.
C. From below it doesn’t even appear that the transfer slots are even exposed (trying to baseline the 0.02 slot square). So when I open the idle speed up its as if it immediately exposes the entire slot.
ill go back out in between conference calls.
fbc - now I’m not so certain that they aren’t pulling too much fuel.......
The following users liked this post:
SB (07-06-2020)