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Discussion Starter · #1 ·
I finally installed my 3700 stall Edge converter! First thing I immediatly noticed was it no longer had that drastic drop in rpms when going from park into gear and sound like it wanted to stall.
I can hear a slight engine rev when pulling from a stop and from going from cruising speed to full throttle.
Throttle response is still nice and crisp though.
It used to spin the tires hard in the 1-2 shift but now it's only a tiny chip, if that anymore. This is a C-4 that does not even have a shift kit yet!
The engine seems to rev quicker and pull harder. I'm hoping to get to the track at the end of the month for a T&T run.
I'll get to see just how much that 2400 stall converter was holding me back. I would like to see a .2 drop in my 60' and another .4 or .5 drop in E.T
I'll post my track results when I get to the track. My best run last year was [email protected] Since then, I have upgraded my fuel system with -8AN line and Holley blue pump with a sumped tank, ditched the 3310 and bought a 750 DP and swapped in my edge converter.
I don't know if the fuel system and carb. swap will increase HP or not. What do you guys think?


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1982 GT
351w(.060), ported & polished heads with 1.94/1.60 valves, 10.3 comp, stealth intake, 274XE cam, Holley 750 dp, Mallory dist., shorty headers, flowmasters, 4:10 gear, c-4 with 3700 stall converter, subframes, electric fan

<font size=-1>[ This Message was edited by: 82GT on 4/23/06 3:09am ]</font>
 

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I think your combination was down on power last year or you were running heavy. Your trap speed would be in the 110 area if everything was working right with what you got. I'm feeding a 347 with a 650 carb with a completeley stock '83 fuel system and its plenty enough. It went 12.8 at 109 last fall with home ported E7 heads. Your combo should do as well or better with that XE274 cam. What are you running for total ignition advance? Are you having serious traction issues?
Bruce
 

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Discussion Starter · #3 ·
I was bogging off the start last year. It wouldn't pick up until around the 60' mark. I don't know if that was fuel related or lack of stall speed....or both. I was running about 38* total advance but that's going to have to be backed down when the nitrous is installed.
I know the major lack of stall speed wasn't helping my times at all.
 

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82GT, Unless you discovered on a dyno that 38 degrees total was the best for your combination I would say you got 4 or 5 drgrees to much advance for best power. I'm just guessing but you probably have it set that high because it runs better down low with the amount of initial that gives you 38 degrees total. With your cam you need a lot of initial to get a good bottom end, like maybe 16-18 degrees. What are you running for initial? If you've had to pull the initial back to limit your total to 38 degrees (to much I think!) you will end up with a bog. I went through this last year with my 85 HO distributor and had it recurved at a shop this winter. I run 18 initial now and 34 total. The 34 total was arrived at on a chassis dyno. Cost $60 bucks to have it recurved but picked up 40 ft pounds of torque by dropping the total back
plus the motor flat out barks at you right off of idle with 18 initial.
I would say the bog was probably not fuel supply related as fuel demand
is pretty low at the rpm you where bogging at. If your interested I can hook you up with a shop in Minneapolis that will recurve your distributor for $60, or at least that what he charged me. What carb is a 3310?Bruce
 

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Discussion Starter · #5 ·
My initial is at 14* with mechanical advance set at 24* That's about as high as I can run, on 93 octane, without detonation. I've messed around with different advance rate springs in my dizzy. I have total advance in by 2500 rpms. You think I should back initial down to 10* so it's around 34* total?
How could a shop recurve my dizzy without the car on a dyno?
BTW, a 3310 carb. is a vacuum secondary 750 Holley. I have switched to a 4150, which is the double pumper version.
 

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How could a shop recurve my dizzy without the car on a dyno?
Just tell them what timing you want to run, and by when and bobs your uncle.
 

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What XDCLEVO said.
You don't want to back your initial off, that will make the bog worse and your low end torque will suffer. With your cam I would run 16 to 18 initial and 34 total. Guys that have studied this stuff in depth pretty much agree that a good sized V8 will make max power at or below 34 degrees total advance. My experience on the dyno has been the same, although I really just have dyno experience with one motor. Also, the installation instructions that came with my KB pistons talked about it, said set full advance at or below 34 degrees. So in your case you want to keep the high initial or maybe bump it up a degree or two and limit the full advance to 34 or less. The guy that did my distributor welded up the advance slot and re-cut it so that the mechanical advance couldn't put in more then 16 or 17 degrees of timing. That way I (and you!) can run a lot of initial without going past the sweet spot on mechanical at high revs. What's important here is that unless you've got something really unusual about your engine the 38 degrees of full advance is keeping your motor from making max torque and HP. Advancing the timming until just before detonation will not get you max torque. It will give you a 'seat of the pants' feel that the motor is running stronger at low RPMs (and it is) but when you wind that puppy up like you do on the strip your going to be missing some hard earned power up high in the rev range. Also, I would be thinking about some more performance oriented headers. You didn't mention if your headers where equal length or not. Long tubes or equal length shorties
will usually do better then just shorties. Bruce
 

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Discussion Starter · #9 ·
If my mechanical is set at 24* then I wouldn't be able to run 16-18* initial because that would put me at 40-42* total advance!
Are you suggesting that I reset my mechanical advance, in the dizzy, to about 18* and run 16-18* initial to give me 34 total?
I'm not sure if I follow what you are saying. I "think" you're saying I should have less mechanical and more initial timing and lock the mechanical advance.
BTW, I have BBK unequal length shorty headers.
 

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If you want to run 24* initial advance, then have your distributor recurved so its all in by lets say, 2400 rpms, and you will only have 10-12* worth of mechanical advance built into it.

With my old Mallory distributor, I had about 8-10* mechanical advance and had about 26* initial. That was as high as I could go on the initial side before it wouldn't turn over very good when warmed up.

Now that I have a MSD Digital 6-plus with the start retard built into it, I have my MSD distributor locked on 35 degrees total timing and the engine loves it. I would highly recommend locking the timing if its something that you can tolerate.

Just my 2 cents
 

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Discussion Starter · #11 ·
What ill-effects would locking the dizzy have on a car that is sometimes driven on the street?
I would have to find a place that could do this for me.
 

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82GT
Locking the timming to 35 degrees would make it very hard to start hot unless you have some mechanism to retard the timming on start up.
It also could be hard to start cold depending on you starter.

Here's the info on the guy in Minneapolis that does recurving.
Don's Ignition Service, 763-755-7781. The guy is a retired drag racer and has a wealth of knowledge about ignition, cams, suspension, just about anything racing related actually. He also has a Sun distributor machine. You can actually weld up and re-cut the slot in your mechanical advance weight yourself but the hassle factor just isn't worth the $60 bucks that Don charges. If you do it yourself it will probably take you several tries to get it just right, like an all weekend project. Give him a call if you want that motor to make all the power it can make with your existing combo. Bruce
 

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Discussion Starter · #13 ·
Is there any way to change the mechanical advance(in the dizzy) myself or is that where the ignition shop comes in?
The instructions that came with my distributor says it's factory set at 24*
This is why I can barely get 14* at the crank without detonation.
To get 34-35* total, I would have to back the initial down to 10-11*
See what I'm sayin?
 

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Yes, you can do what the guy at the ignition shop does but it will be a trial and error thing. The ignition shop guy has a Sun dizzy machine so
he doesn't have to pull and reinstall the dizzy 4 or 5 times to get it just right. I haven't seen the inside of a Mallory distributor but the principle is the same on all of them. You just do what you have to do to limit full advance. Maybe you could call Mallory and see if they have fly weights for different amounts of full advance? Just a thought. Bruce
 

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82GT,
What type of Mallory distributor is it? If its a Comp 9000 distributor, Mallory has a kit that will allow you to adjust the mechanical advance. Its a very simple task and a screw is loosened and then you can adjust the width of the slot with the supplied spacers, tighten the screw back up and pull the spacer out. Its that simple.
 

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Discussion Starter · #16 ·
My dizzy is a unilite model (37 series)
I think I still have the instructions some place. I'll have to dig them out and see. You would think Mallory would allow mechanical advance adjustments on all their models.....
 

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Here is the pdf file of the instructions for your distributor. http://go.mrgasket.com/pdf/29014.pdf
I believe that yours is the YT series. It looks like you can just bend the tab and experiment with the mechanical advance. A little trial and error and it'll save ya the 60 bucks.

_________________
1982 F100 - 357c w/ stuffed 4v's and Funnelweb. C-6 trans, Gear Vendors o.d. and 4.86 geared Detroit Locker 9" rear. http://www.supermotors.org/registry/vehicles/detail.php?id=6723

<font size=-1>[ This Message was edited by: f100cleveland on 4/27/06 4:56am ]</font>
 

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Discussion Starter · #18 ·
I think that only adjusts the rpm at where the advance starts the curve.
I don't think it will limit the amount of advance....unless my understanding on how mechanical advance works is incorrect...which is also possible.
 

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Ok, look at Figure 4, YT Advance Assembly:
The springs are what control the rpm at which your advance is in by. BUT, the ADVANCE TAB is what limits the amount of mechanical advance that you will get. The pictures show arrows that either give you more advance or less advance by bending the ADVANCE TAB. I hope that gives you a little better understanding on the advance.
 

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Discussion Starter · #20 ·
Ahhh....gotch ya I see now. Thanks for the info!
 
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