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How To: 15 Second Slant?
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Author:  Swingin 74 [ Thu Jun 10, 2004 8:07 pm ]
Post subject:  How To: 15 Second Slant?
what can i do to get my 74 swinger into the 15's or low 16's? its got a 7.25 with 2.76s, 904 and a super six. will 3.23 gears be low enough? is the bbd enough carb to get me there or will i have to swap to a 4 bbl? how much head work is necessary? will decking it and polishing and porting the bowls be enough or do i need larger valves? what cam would be good? will i have to change out the torque converter? how fast can i ago using the stock converter?

swingin 74
Author:  Dennis Weaver [ Thu Jun 10, 2004 8:46 pm ]
Post subject: 
Here are my specs to give you some ideas... Car has recently run 15.58. Full Story in "Slixer's Gallery". Remember, there's more than one way to skin a cat, this is just food for thought. I think I can make the car a good bit quicker with the same basic setup if I can get it to launch harder...

S/D Six Duster specs:

>Original 225 block bored .060 over (that comes out to something like 232 for the "chevy types" who like to add up all the new-found displacement - Don't want people thinking I'm running a Jeep motor, though...)
>Stock l/c cast pistons (flopped), stock "loose" bottom end
>Stock oiling (filter relocated right-side up, w/ check valve). Adjustable pressure relief spring.
>Comp Cams 264S (264 deg adv duration, .440" lift)
>Ported, polished, "blueprinted" head (mid '70's taper plug style). Stock dia backcut valves, 340 springs w/ dampers. 9.14:1 compression
>Offy four barrel intake, Carter 4294S AFB (rated 400CFM), stock Carter pump, fresh air induction
>Stock Chrysler Electronic ign, orange ECU, accel coil, stock resistor.
>Clifford Research full length headers, 3 into 2, crossover pipe, duals.
>Lightweight ND starter/alternator/compressor
>Original (but tweaked) 904 trans, 2.74:1 low gear planetaries. TCI "Breakaway" converter stalling at approx. 2200RPM
>7.25" 3.23:1 open differential.
>Time trials are run on 14X6" Cragar s/s shod with 22" tall T/A drag radials.
>approx. 3050lbs, 3300lbs race weight w/ driver.
Author:  Dart270 [ Fri Jun 11, 2004 6:50 am ]
Post subject: 
Dennis has a very nice street setup there. That's pretty close to what I'd run for that purpose.

My guess is that the head work is responsible for much of the power in that combo, and having a matched cam/carb/head combo.

Lou
Author:  swingin 74 [ Fri Jun 11, 2004 8:26 am ]
Post subject: 
how fast can i go with the super six and 318 bbd? what about the stall converter? whats the cut off point for the stock conveter and a bbd where they will be the units that are holding me back? i didnt really want to mess with the stall on the car and would like to keep the super six. what about a comp cams 254 cam? dennis, do you have to run 93 octane in your car?
Author:  Dennis Weaver [ Fri Jun 11, 2004 10:10 am ]
Post subject: 
I do run "super unleaded", but could probably get by on "plus" as long as I stayed out of it. I usually blend in a gallon or two of race gas at the track just to keep the detonation at bay, but 92 or 93 octane does fine for street driving. That's with the total timing set @ 35deg (I think - haven't messed with it in a while (I set it where my old D/C Engine Book advised and saw no improvement at the track by varying from it).

I can't answer your other questions definitively, but my guess with a bone stock converter (mine isn't that much looser) and a BBD, you're probably going to be limiting yourself to the 17 sec range. You could try a bigger two-barrel from a 360 or something, but you'll probably kill your throttle response and low-end driveability a little bit. The 254 cam you mention (advertised duration?) is pretty tiny, too. Believe me, the 264 (adv.) is almost too smooth of an idle and very tame. That's the smallest I'd even bother with, were it me.

D/W
Author:  DusterIdiot [ Fri Jun 11, 2004 11:24 am ]
Post subject:  Even better...
For the same price, if you were to do what Dennis has is to have comp grind an extreme energy cam with the 262 lobe out of their catalog, it's much more aggressive than the 264 Dennis has better lift, and still would have good street manners (stall convertor probably will be needed).

You will want to run the 4 barrel to do what you want to do. You could try a big two barrel, but most are similar to the primaries of a 4 barrel anyway...no sense in going to one setup then being disappointed and having to buy a second setup...
Quote:
You could try a bigger two-barrel from a 360 or something, but you'll probably kill your throttle response and low-end driveability a little bit.
2 barrel from a 360? OMG Dennis! Did I just hear you recommend a Holley 2245 to this guy? A Holley?!?!? :wink:


-D.Idiot
Author:  Dennis Weaver [ Fri Jun 11, 2004 12:47 pm ]
Post subject:  Re: Even better...
Quote:
2 barrel from a 360? OMG Dennis! Did I just hear you recommend a Holley 2245 to this guy? A Holley?!?!? :wink:


-D.Idiot
Yeah, my bad... I couldn't remember if you could get a 360 with the big BBD, but I think you're right - they were all Holley smogger carbs, though even the 2245 and the like are a better design than the 4150/60's, in my humble opinion. I guess I should have said a two-barrel off a 383 or 361... Good catch ;)

D/W
Author:  DusterIdiot [ Fri Jun 11, 2004 12:52 pm ]
Post subject:  Lol...
Lucky you didn't say 1971, 383 or 400...Then I'd rib you for the Holley 2210...The larger BBD could be had on big block 2 barrels through 1970...
Unfortunately they have a different bolt pattern than the more common adaptor (like small BBD to Holley 2300), the 'big two barrels have a similar bolt pattern to the Holley 5200/Weber DGAV found on Pinto's and late 70's/early 80's Mustangs...


:wink:

-D.Idiot
Author:  Dennis Weaver [ Fri Jun 11, 2004 1:01 pm ]
Post subject: 
...I hereby defer all two-barrel expertise to DusterIdiot. ;)

D/W
Author:  66Dart [ Fri Jun 11, 2004 1:14 pm ]
Post subject: 
My setup has similar components to those of Dennis'. Setup consists of:
- .40 over
- Ported and over-size valve Head
- Comp Cam 264S
- 9.2:1 Compression
- Dutra Duals / Dual Exhaust
- Pro-Line Dual Weber Setup
- MP Electronic Ignition
- Lightweight ND starter
- A230 - 3 Speed
- 7.25 - 3.23:1 Open diff.

I am currently in the process of adjusting (jetting and Venturii's) the Webers to make full use of the engine buildup. No specific time trials at this point. Like Dennis, I too am running 92 octane. The Comp 264s is very smooth at idle and is great for the street. I have been driving it daily for the last month and it is very reliable, quick, and fun to drive. I am getting approx. 16 mpg City / 21 Hwy. 'Slixers Gallery' has write up on rebuild process.

Matt
Author:  Rick Covalt [ Sat Jun 12, 2004 5:05 am ]
Post subject:  True 15 second car.
My son's 72 Swinger has gone 15.8's on real street tires. It spun very hard clear through first gear, so with slicks or street slicks I'm sure it would be running some 15 flat's or maybe high 14's His set-up is below:

72 Swinger / full weight (nothing removed or lightened)
.030 over 225
oversized valves
.460, 264 duration cam
8.9 to 1 compression
Offenhouser intake with 600 Carter
6 into 1 MP header
4 speed transmission (OD unit)
4:30 rear gears (posi)
street tires



Note: The OD. makes the 4:30's no problem on the road. But he never got out of 3rd gear at the strip. A straight 4 speed would be faster yet.

Rick
Author:  swingin 74 [ Sat Jun 12, 2004 8:13 am ]
Post subject: 
what bumpstick could i run with the bbd to improve performance? how much does a comp cams cam cost for a slant? with a rebuilt bottom end, a ported and decked head with stock size valves, running about 9:1 CR, super six, stock trans and converter, and some 3.23 gears, what kind of performance do yall think i could expect? would this be enough to get me into the 16's? i just got the car and installed the super six almost immediately so id like to try and keep the super six around for a while longer. if i eventually do switch to the four bbl, how is the kickdown linkage going to work? is alot of fabrication in store?
Author:  Dennis Weaver [ Sat Jun 12, 2004 8:33 am ]
Post subject: 
...The super six set-up is nice - I had my Duster set up that way for years and years. But if you want to go fast, you're gonna need to end your love affair with the BBD.

The linkage for the four-barrel will be no problem, I had set mine up before the Lokar kickdown cable kits were readily available, but that'd be your best bet, I'd think. You could run any cam in in the 260 deg range just fine with your BBD, but I doubt you'd get the results you seek. You're probably going to have more $$$ in your head work than a cam costs, if you are doing it right. I spent a lot of time blending valve seats, porting and cc matching the head. I also had all of the valve seat heights indexed by the machine shop so all of the cylinders would be perfectly matched. Exhaust ports were selectively hogged out and polished like mirrors.

The only real way to find out what you want to know is to try it out. Build the worlds fastest BBD equipped super-six! ;) You can alwez swap to a four-barrel later. Heck, maybe you'll go 16.99, would that satisfy you? :P I noticed you haven't mentioned anything about exhaust... What are your plans there? You'll need to do something to free it up. The stock stuff is definitely not going to cut it.

D/W
Author:  70valiant [ Sat Jun 12, 2004 10:54 am ]
Post subject: 
My 70 Valiant with and aluminum supersix intake, 318 BBD, open elament K&N, electonic ignition using a GM HEI, electric fan, 0.100" shaved off the head and ported, clifford dual headers Y-piped to a single 2.5" exhaust, and turbo muffler, running lean and bad initial timing ran 17.1@80.5mph.
stock cam, 904/w no work done to it ever, an open 7.25 rear w/ 2.76 gears, 26" tall crappy free tires that were made for an SUV.
Good tires, gears and a cam and I'm in the 15's
Author:  Dennis Weaver [ Sat Jun 12, 2004 1:00 pm ]
Post subject: 
...There you go, Swingin' 74 - someone pushing the envelope of BBD performance.

70valiant, very impressive... please file the full report when you take the BBD into the 15's :lol:

D/W
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