Re: Cam too big?
[Re: Dodgem]
#612138
02/13/10 01:52 PM
02/13/10 01:52 PM
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Joined: Dec 2007
Posts: 1,639 Brandon, Ms
cornet684me
OP
top fuel
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OP
top fuel
Joined: Dec 2007
Posts: 1,639
Brandon, Ms
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yes, the floats are fine, the carb. did have a 6.5 power valve, i have replaced with 3.5, i was going to take apart and go down with the jets, i am going to try this next week, a buddy just called he will bring me a good dist. that he has to let me try to see if is my dist.
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Re: Cam too big?
[Re: runinonmt]
#612140
02/13/10 03:19 PM
02/13/10 03:19 PM
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Joined: Nov 2006
Posts: 1,462 oklahoma
forphorty
pro stock
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pro stock
Joined: Nov 2006
Posts: 1,462
oklahoma
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Quote:
Quote:
power valve gasket-not only for tears but position on the power valve
what do you mean the position of the power valve? i did replace the power from 6.5 to 3.5 with a new one
I have seen power valves with the gasket off center sitting on the step allowing a leak. Ron
Yep, the old gaskets had tabs to locate it, i believe. Don't think any of the new ones do. I like to hold the metering block flat when installing the PV.
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Re: Cam too big?
[Re: cornet684me]
#612141
02/13/10 05:20 PM
02/13/10 05:20 PM
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Joined: Mar 2007
Posts: 3,298 West Coast, USA
jbc426
master
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master
Joined: Mar 2007
Posts: 3,298
West Coast, USA
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First things first. What do you have you timing set at, initial and total?
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's 1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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Re: Cam too big?
[Re: MoparDonny]
#612143
02/13/10 10:17 PM
02/13/10 10:17 PM
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Joined: Dec 2003
Posts: 5,314 Carstairs, Alberta, Canada
dave571
master
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master
Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
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A couple of things.
What you are describing is typical of a low comp engine with a larger cam and not enough intiial timing. You can jet it all day, if you like. But it won't run any better till the timing is sorted out.
.050 off the heads of a motor with the pistons .170 in the hole, doesn't do much. It'll be 8:1 on a good day.
Ideally, I think you want to advance that cam 4 degree's or so to make it better down low..
The rock stock converter isn't doing you any favors. The misconception is that you can't drive a converter with more stall on the street. A well built performance converter will drive like a stocker under light throttle, and flash to a higher rpm on hard launch. A 3K converter would be a nice match for that.
If I was curving a distributor for you, I'd recommend 18 intial, and 35 total all in by 2800.
The 3.55's are fine. I run way more cam with 3.73's, and didn't lose any ET when I switched from the 4.10's I had before the 3.73's.
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Re: Cam too big?
[Re: cornet684me]
#612144
02/14/10 12:07 AM
02/14/10 12:07 AM
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Joined: Apr 2005
Posts: 12,271 Overpriced Housing Central
RobX4406
I Live Here
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I Live Here
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
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Quote:
i cannot figure out where the timing is, however, i know the timing is not the issue here
ummmm, yeah ok... yet it's fuming you out...
If you give the engine more initial advance does it pick up RPM?
That cam should idle below 1000rpm.
I wonder if you turn the idle down you get a drop in timing. Mechanical being bled in at a low RPM. Happens all the time.
The carb is running on the transfer slots, that's part of the reason it's fuming you out.
If you don't have a timing tape, do a hillbilly timing tape. With the timing mark on the pass side, turn the balancer line to the bottommost indicator mark, mark a line 15* towards the top of balancer, turn the new marked line down to the lowest tab mark and make another mark 15* up. Now you can get the timing set in a range to about 45* BTDC.
DO NOT set the car using the total timing method. Set it by most vacuum/constant rpm, starter kickback or advancing until it no longer pick up RPM/resetting to constant. Somewhere in the 16-22* range should work. Shoot for an idle rpm of 900 in park.
Baseline the carb at 1.5 turns out on the idle mix screws. Start over.
DO NOT be concerned with total timing now. That's the second piece of the puzzle.
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Re: Cam too big?
[Re: RobX4406]
#612145
02/14/10 01:31 AM
02/14/10 01:31 AM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Like I said before timing affects fueling, fueling does not affect timing get that timing setup correctly initial AND total before you even dink around with the carb. Until you do that you are wasting your time. I run a 76 440 with stock pistons and the lunati 60303 cam which is 226/234 @ 050 to your 230/236 not much difference. Mine runs/drives just as cleanly as it did with the stock lo-po cam which is said to be more like 210. This combo loves a well tuned distributor, you can NOT just bolt one in right out of the box and go. Mine likes 18* initial, maybe more yet, but I had been running it (needlessly) on pump 94. You will want a lot of initial timing like that, with the total near 40 all in somewhere around 2500. You need either a dial back timing light or timing tape for your balancer. Once that distributor is dialed in, then and only then start to tinker with the carb. Without the correct timing, you will not be able to tune out that bad bog when you snap to WOT nor will you get any kind of a clean burn.
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Re: Cam too big?
[Re: cornet684me]
#612146
02/14/10 01:34 AM
02/14/10 01:34 AM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
so what you are saying is, with some tuning , i should be able to make this set up work, i have the motor in a 1968 dodge coronet, 727 with stock covertor and i have 3.55 gears,
Stock converter is doing you no favors, and the 3.55 gears are marginal but doable. The problem with the stock converter is you're only going to get a 2000rpm flash out of it and your motor is going to be soggy and not respond the best when you snap to full throttle and the motor is not able to flash stall to above the rpm where your total timing is in at. The smogger CR motors are more sensitive to the correct balance of timing and stall than this same cam in a 10:1 440 would be.
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Re: Cam too big?
[Re: DaytonaTurbo]
#612147
02/14/10 02:08 AM
02/14/10 02:08 AM
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Joined: Dec 2003
Posts: 5,314 Carstairs, Alberta, Canada
dave571
master
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master
Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
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Quote:
Stock converter is doing you no favors,
quoting me
Quote:
The rock stock converter isn't doing you any favors.
Great minds think alike...LOL
Quote:
The smogger CR motors are more sensitive to the correct balance of timing and stall than this same cam in a 10:1 440 would be.
For sure. The lower comp makes for a lazy burn. Needs more timing sooner, to compensate.
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Re: Cam too big?
[Re: cornet684me]
#612151
02/16/10 12:34 AM
02/16/10 12:34 AM
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Joined: Dec 2007
Posts: 1,639 Brandon, Ms
cornet684me
OP
top fuel
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OP
top fuel
Joined: Dec 2007
Posts: 1,639
Brandon, Ms
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wow, thanks for all the input, from what i am reading, sounds like i need to get someone over to my house to teach me about timing, i have tried all the tricks everyone is saying, i have marked top dead center, put timing tape 2 1/4" and 1", the problem is i cannot get the car to run correctly trying to do this by the book timing, when i try to do by the book, the car runs like crap, then i hook up the vac. gauge and do it by ear and feel, i get the car running great, except for the flumes out the exhaust, i am going to break down and load it up on trailer and take it to expert in timing next week, i will give Moparts update, everyone has told me the problem is in the Timing, and the only reason i avoided it , is because i really do not know anything about getting this done, i was hoping to put some jets in carb and fix it, i should have known , this wld be too easy, Thanks for everyone's thoughts and input, i really think it is the timing too, i think i am running 18 to 20degress at idle, i cannot figure out the total timing yet, i have been just trying to do the timing by ear, vac. gauge and feel, starter drag etc., i guess this old shade tree trick is not going to work with a high performance cam, i will get back with Moparts once i try to get the timing thing sorted out!
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