Bog off the line ?

CJohnson · 08-27-2009, 03:14 AM

Hey guys.

I am having troubles with a bog / stutter off the line. I have gotten used to launching the car like this but I would like to know what the cause of the bog is

its a mild 355
Flat top pistons
Hydraulic roller cam .510/.520 lift (not sure on the duration)
Edelbrock performer RPM heads

It has a 750 holley (vaccume secondarys) on it right now currently jetted at 68 - 73's it used to have 70 - 75's but the change did not seem to make to big of a difference

I do have access to a 750 holley mechanical secondaries would this be significantly better ? i've heard the vaccume secondaries are more for street use and bog off instant WOT ?

Like i said it just kind of stutters and then takes off.

any help is appreciated, Thanks.

Craig
C693

kennyd · 08-27-2009, 09:08 AM

go up 1 size on squirter, and pos .5 to 1.0 higher # power valve if vaccum will allow, what kind of vac nos does it pull idling in gear

Chris1529 · 08-27-2009, 09:34 AM

I agree that you need a different squirter. I would take a bigger swing at it than one size though.

what size is in it now? probably a low thirties. I'd go up into t he low to mid 40's on squirter size.

you have a momentary lean condition which is causing this problem.

Hans Olsson · 08-27-2009, 09:39 AM

Craig,
what are your 60ft time?

BlueOval Ralph · 08-27-2009, 11:20 AM

1. Make sure you have full travel on acc pump arm with.015 clearance at full stroke
2. Use red pump cam as i remember it is a #330 in the full postion.
3. If you get into a .040 range squrt. You need the hollow pump screw. Don't over tighten it.
4. It would also help to open the Idle Feed restriction in metering body about .003 (usally .033 or.035.

Quote:

Originally Posted by Chris1529

I agree that you need a different squirter. I would take a bigger swing at it than one size though.

what size is in it now? probably a low thirties. I'd go up into t he low to mid 40's on squirter size.

you have a momentary lean condition which is causing this problem.

CJohnson · 08-27-2009, 12:20 PM

Hey, guys thanks for all your help. Here are the specs on my carb

holley 750 4150
PRI Shooter - 25
PRI Pump Cam - 330 #1
Power Valve - 6.5
Second Spring - Purple

The car runs mid - low 13's and ive cut a best of a 1.880 but this is with my 12 bolt in my cutlass with stock upper and lower control arms, my pinion angle was off by a mile. Now it's set up right with adjustable 12 bolt uppers no hop bars drag shocks ect.

I'm racing this weekend and i'm going to try some changes to the carb on the friday test and tune.

CJohnson · 08-27-2009, 02:56 PM

Thanks, I went to mopac today and picked up some bigger squirters 37's were the biggest they had should be a big difference from the 25's i had in there ? and I also picked up a 7.5 power valve 1 size up from the 6.5 i had. I will try it at the track tomorrow.

blasttime · 08-27-2009, 03:16 PM

Take your squirter and calipers to a hobby shop and buy a pin vice and drill bits its cheaper than buying squirters. There very easy to drill out. Have a great day

CJohnson · 08-27-2009, 03:19 PM

Quote:

Originally Posted by blasttime

Take your squirter and calipers to a hobby shop and buy a pin vice and drill bits its cheaper than buying squirters. There very easy to drill out. Have a great day

Thanks, good idea but i have already bought the squirters

Jody Lang · 08-27-2009, 08:30 PM

I think your sec. spring is too light for your combination. Start your weekend out with the plain (stock) spring and be prepared to try a heavier one.

The heads might be a little big for your combination and might also need a bigger squirter to make up for lack of velocity.

Is this a #3310?

My bracket car has a 3310 on it. It runs mid 11s. Plain spring, 72 76 jets with a 028 squirter.

Good luck.

08-27-2009, 09:08 AM	#2
kennyd Junior Member Join Date: Aug 2006 Location: Tyler Texas Posts: 28 Likes: 0 Liked 0 Times in 0 Posts	Re: Bog off the line ? go up 1 size on squirter, and pos .5 to 1.0 higher # power valve if vaccum will allow, what kind of vac nos does it pull idling in gear

08-27-2009, 09:39 AM	#4
Hans Olsson Member Join Date: Nov 2001 Location: Sweden Posts: 103 Likes: 0 Liked 0 Times in 0 Posts	Re: Bog off the line ? Craig, what are your 60ft time?

08-27-2009, 12:20 PM	#6
CJohnson Junior Member Join Date: Jul 2009 Location: .005 ahead of you Posts: 38 Likes: 0 Liked 0 Times in 0 Posts	Re: Bog off the line ? Hey, guys thanks for all your help. Here are the specs on my carb holley 750 4150 PRI Shooter - 25 PRI Pump Cam - 330 #1 Power Valve - 6.5 Second Spring - Purple The car runs mid - low 13's and ive cut a best of a 1.880 but this is with my 12 bolt in my cutlass with stock upper and lower control arms, my pinion angle was off by a mile. Now it's set up right with adjustable 12 bolt uppers no hop bars drag shocks ect. I'm racing this weekend and i'm going to try some changes to the carb on the friday test and tune. Last edited by CJohnson; 08-27-2009 at 12:22 PM.

08-27-2009, 02:56 PM	#7
CJohnson Junior Member Join Date: Jul 2009 Location: .005 ahead of you Posts: 38 Likes: 0 Liked 0 Times in 0 Posts	Re: Bog off the line ? Thanks, I went to mopac today and picked up some bigger squirters 37's were the biggest they had should be a big difference from the 25's i had in there ? and I also picked up a 7.5 power valve 1 size up from the 6.5 i had. I will try it at the track tomorrow.

08-27-2009, 03:16 PM	#8
blasttime Junior Member Join Date: Feb 2009 Posts: 43 Likes: 0 Liked 0 Times in 0 Posts	Re: Bog off the line ? Take your squirter and calipers to a hobby shop and buy a pin vice and drill bits its cheaper than buying squirters. There very easy to drill out. Have a great day

08-27-2009, 03:14 AM	#1
CJohnson Junior Member Join Date: Jul 2009 Location: .005 ahead of you Posts: 38 Likes: 0 Liked 0 Times in 0 Posts	Bog off the line ? Hey guys. I am having troubles with a bog / stutter off the line. I have gotten used to launching the car like this but I would like to know what the cause of the bog is its a mild 355 Flat top pistons Hydraulic roller cam .510/.520 lift (not sure on the duration) Edelbrock performer RPM heads It has a 750 holley (vaccume secondarys) on it right now currently jetted at 68 - 73's it used to have 70 - 75's but the change did not seem to make to big of a difference I do have access to a 750 holley mechanical secondaries would this be significantly better ? i've heard the vaccume secondaries are more for street use and bog off instant WOT ? Like i said it just kind of stutters and then takes off. any help is appreciated, Thanks. Craig C693

08-27-2009, 09:34 AM	#3
Chris1529 VIP Member Join Date: Dec 2006 Location: West Virginia Posts: 1,367 Likes: 6 Liked 57 Times in 27 Posts	Re: Bog off the line ? I agree that you need a different squirter. I would take a bigger swing at it than one size though. what size is in it now? probably a low thirties. I'd go up into t he low to mid 40's on squirter size. you have a momentary lean condition which is causing this problem. __________________ Chris Bowman The Mountain State Mustang 1984 Mustang GT350

08-27-2009, 08:30 PM	#10
Jody Lang Member Join Date: Mar 2002 Posts: 299 Likes: 28 Liked 81 Times in 25 Posts	Re: Bog off the line ? I think your sec. spring is too light for your combination. Start your weekend out with the plain (stock) spring and be prepared to try a heavier one. The heads might be a little big for your combination and might also need a bigger squirter to make up for lack of velocity. Is this a #3310? My bracket car has a 3310 on it. It runs mid 11s. Plain spring, 72 76 jets with a 028 squirter. Good luck.