I can't stand it anymore! Bench race my combo!

[The Dartman]

Okay, I can't stand it anymore. Now that I am actually getting close to racing my new combo, I am dying to find out what it will run. Racing is still two weeks away, so let's take some guesses!

My combo is this:

Engine:
1978 440, 30 over, cast crank, 10.22:1 CR
516 heads, fully ported and polished, 2.14/1.81 valves
Mopar Hydraulic .509 Camshaft, non adjustable valve gear
Mopar M1, 1 Inch 4 hole spacer, Holley 750 double pumper
Hooker Super Comp Fenderwell headers, 1 7/8 variety

Transmission:
Cheetah reverse full manual valve body
Bolt in sprag
5:1 shift lever

Rearend:
Greg Moser race axles
742 case, with 4.30 gears
Clutch style sure grip

Tires:
Rear: 13.5 Mickey Thompsen Sportsman ET's
Front: Volkswagan "pizza cutters"

The Car:
1973 Duster
Fiberglass hood, front and rear bumpers
Ten point cage
Mini tubbed
Super stock springs
8 AN fuel lines supplied by Mallory return style regulator
Weight w/318: 3165
Weigth w/440: 3305
Weight with overweight driver: 3560

This combo has a few known weak areas, all having to do with fuel delivery. One of these is the fact that the 750 will limit top end power, the other is the Mopar cam. Both of these were necessary evils for this fairly budget conscious build since the 750 was on my 318, and the Mopar cam, lifters, pushrods, valve springs, lock and retiainers were all purchased as a kit for around $350.

By my educated calculations, this combo should run in the vicinity of 11.80 to 12.20. I have seen similiar combos run much slower than that, yet there are some running faster as well. The biggest qeustion mark in the combo is the heads... will they flow well enough? I imagine a set of fully ported steel 516 heads would be lucky to see 250-270 CFM in flow at 600, that's why I used a considerably smaller number in my calcs.

Any guesses as to the ET?

Thanks!
Scott

[B1owner]

11.80's to .90's...

[345Dart]

What dia. are the tires and what TC (flash rpm) are you running?

3560?? Hmmmm.

[DartGT66]

I think you've got a decent package. Should run high 11's if everything works well, but what tires are those: 13.5 Mickey Thompsen Sportsman ET's ?
If they are sportsmans, there may not be enough traction, but if they are ET Streets you should be OK. Let us know how it went.

[The Dartman]

The Torque Converter is a 9 inch TCI 3800 stall.

The tires are ET Streets, they are 28.5X13.5.

I failed to mention that I have an MSD6AL with a two step.

My big brother just ran 11.19@118 in his 4000 pound Oldsmobile last weekend (on a 100 shot of the juice), so the closer I am to that big dope the better. He runs 11.80's on the motor...

Thanks!
Dartman

[DartGT66]

If you can really get that combo dialed in, you might get close to low 11's. I think your combo is pretty decent. Might use a 850 instead of a 750 though, I think you'll loose some peak power with the 750. 516 head castings aren't teh best ones either, you may loose a little there too, but they still should work decently. Next step in my book would be a bigger solid lifter cam.

[The Dartman]

That is the basic idea: Get the car switched over to a big block and just get past that expen$e, and then tweak my combo for ET. I was thinking of a mid 500 lift solid with Crane rocker gear as a place to start for next year sometime.

Dartman

[pishta]

bigger cam? Just go with a larger ratio rocker arm, way easier and you dont gain duration, youll have to go adjustable though along with pushrods unless you get the ones that have cups as adjusters. pretty cheap nowdays as China is poppen them out by the boat full.

[The Dartman]

Thanks for all of the replies. I got the car to the dragstrip this weekend, but failed to make a pass.

I have been fighting some timing, ignition, and carberation problems since it's been together. Yesterday at the track I thought I could finally nail them down, since I could tune it without making my neighbors cringe at the sounds of open headers in my somewhat upscale neighborhood. The car would pop and backfire out of the passenger's side, getting worse as the car revved up. At idle it was barely noticible. I changed plugs, timing, adjusted my carb, and tested the plug wires all without finding the culprit. I also checked for a flat cam as well. After chalking up the day as a loss, I put it back together to put it on the trailer, and a funny thing happened...

It ran fine! I noticed a slight pop when I punched it hard, but I was able to get on it a little on pit road to see how it ran. It revved so fast I hit 6 grand in low in the pits! I immediately ran right up to get the car in staging lanes, and it started drizzling and later the skies REALLY opened up and dumped some serious rain down.

My guess is that the wires to my alternator (in a 3/8 plastic wire loom) were sandwiched between the valve cover and the distributer cap. Even while moving the distributer to time the car, I think that the loom forced the cap to be slghtly cocked on the distributor and the root of all of these problems.

The chevy boys came over and told me my problem was all related to being under carberated (this is a 750 mechanicalk duble pumper). I'm sorry, but being under carberated will not cause problems "off idle".

I am shooting to get it back out next weekend, which is the last event at my local track for the year.

Wish me luck! Dartman

PS - My dipsh!t brother ran in 10.98 in his Olds...

[The Dartman]

Well, we were almost rained out again, but I managed to make two passes. The car still has soem ignition issues, and the pops, cutouts, hesitations continue. I wanted to rule out carberation, so I borrored the 800 CFm carb off my friend's 11.40 Duster. I thought everything would be okay, but it wasn't...

The car a best of 12.07@110, with a 1.73 60 foot time.

Not too bad when you consider how bad it was popping and cutting out throughout the RPM range. I believe there is probably at least 3 tenths on the table once those problems are identified. My burnouts were less than spectacular, being the culprit for relatively slow 60 foot times. It is not really revelant until miss/pop/cutout is taking care of anyway...

I will replace the plugs, wires, cap, rotor for next year and see what I come up with. The funny thing to me is that is idles and revs up fine in nuetral, but once in gear and under a load, the problem starts. This MSD 6AL was tested late last year, so I do not expect that it is the problem. I also don't believe that the problem lies in the valvetrain either, either with a bad spring and a flat cam (which I already casually checked for).

Thanks!
Dartman