Ive got an 40 some years old Pro Stock Hemi I run in my 1970 Charger.

Comp. about 12.7:1
Nothing special about the crank (Kellog), the Nascar rods or Venolia Hi-Top pistons, other than they are on the heavy side...

Heads are old Aluminium D4A Mullen ported heads. No clue about flow numbers..

Indy 426-I4-4 4500 high rise single four manifold that has been gasket ported.

1050 Dominator (#8896) converted to E85

I detuned the engine to be more street friendly, it came with a click for cam spec. camshaft, I thought it to be kinda on the wildside to run it on the street.. so I replaced it with this cam click for cam spec.

OK, problem, or more disspointment came once I got the car to the track.. I really thought it would be faster.. I had hopes to run in the mid 11sec.

Any ways.. I also have to write that I am a compleat novise when it comes to dragracing, so the 60 feet and reaction times could of course be better...

This is my best run.

Reaction: 0.76
60 foot: 1.83
1/8 speed: 91.1mph
1/8 time: 7.82
Trap speed: 116mph
ET: 12.1235

The car is not a lightweight, my guess is that it will hit close to 4400lbs ontop of a scale
Car itself has been built according to the Mopar Chassis book. Rear axel is a DR. Diff piece with 4.56:1 gears. Run 28" Racemaster Dragradial tires (325/50-15).. I have no video of launch to post at this time, but it felt like the tires did hook.. 727 trans built to take abuse. Converter is a Dynamic 9½" piece.

OK, so the weird part is that the engine seems to compleatly lack power in first gear, it does how ever really feel to pull in second and third. Shiftpoint is at 7100rpm.. A/F is way on the rich side at WOT, about 12.2 A/F (Run E85 so its an ok number I guess)

So my questions are:

1. Did I choke the life our of the engine with my choise of camshaft? (I do have plans on running the engine with Nitrous)

2. Or is this the 1/4 mile times to expect with a car that weighs as much as my Charger?

3. Im a compleat clot and should not be let any where near engines or tools...

Thanks...

/Tom

I suspect the converter is the culprit. You have a heavy car w/ a large volume intake, a big set of heads, and relatively small cubic inches. I'm guessing it's around 438 cubic inches? Stock stroke crank? That motor wants to rev, like all hemis do, so it's gonna need a loose converter. Where does your current converter flash to?

116 MPH is enough to go mid 11s, just need to get it to 60 foot.

Big ports small cam are one reason and coverter

I agree with HEMIFRED.

But I vote on #3 anyway Just kidding.

These guys need to know what rpm the converter stalls at. Put the trans in third gear, foot break it, and see what rpm the car tries to move. If you plan on running the car on nitrous, it will seem a little slow running it N/A. Can't have the best of both. I say check the converter stall, let us know where it is at, and I am willing to bet it is probably low for running your set up N/A but will be great when you spray it. BTW, spray won't be band-aid for you, if you already planned using. If you told PTC you planned on spray, they set your converter up for it. You may have too much gear for spray, though. Let us see what some others say.

P.S. What rpm do you launch the car at?

Tom, yes the nitrous is just a bandaid on a "not so good" package.
With those huge ports, your airspeed will suffer bad, so bigger cam or smaller ports.

It's hard to build a (small) N/A high horsepower combination for both street cruising and strip.

I think Chip is dead-on in his assesments. I'll also add that if you've 'rebuilt' these heads with a valve job it's quite possible some performance was lost there. There are many engine builders on this site whom can direct your choice of camshaft assuming the one your using is wrong for your application.

Ill check up on the converter flash and report back.. I have no exact recollection of what kind of stall rpm I managed to hold at the line, guess about +2000rpm.. Like I wrote earlier, im a compleat noob, so al my sences were on overload..

Jocke* Your so right, the engine is a compromize right now.. On a positive note, it will probably run the mid 11sec number, once I learn to operate the thing.. And for the future of the engine I guess a large cubic inch stroker bottom end would be the best choise...

/Tom

stroke it to a 540 or so, that'll move some air in your big heads.
I did a similar injustice to a 400 once, well ported 906s and a big cam and manifold didnt work well at all. especialy on the street.

I agree with Chip......it makes enough power to go at least 11.40's, with the right converter.......so it's NOT cubic inches or the camshaft holding you back from reaching your goal.......

When I got my car in 1982 the motor had almost all those same parts - Mullens ported alum heads, TRW pistons, 292 roller cam. When I had it rebuilt in 2000 the main changes were modern JE pistons, a 4.15 crank (477ci), and a Cam Motion 282 cam. It went from 650hp to 770hp, 550ft-lbs to 660ft-lbs, on the same dyno, with the crossram and carbs unchanged. I think those old pistons lose a lot compared to new, and those heads really want a stroker crank.

Edit: I agree the converter may be a problem. Just remember the best one for this combo will likely be too loose if you later build a stroker.

Quote:

---

The heads are heavily carved out, one could almost stick a fist and arm through the int./exhaust ports,

---

you have the wrong Mullin port for your use.
those sound like the heads they did for blower cars with this exhaust port.
way too much exhaust flow. and the same goes for the for intake ports. tremedous flow numbers but produce very little velocity needed for a n/a combo

this is their pro stock port.

.above head stampings

Hemifred*

The number stamped on the heads seems to be 1758 (Sorry about the bad picture quality, I cant for the life of me find the larger original picture)



To my knowledge this engine never ran as a supercharged engine. This is the engine from the Brooklyn Heavy Duster..



/Tom

if so then that's a n/a head unless the exhaust port was modified. this are large ports that's a fact. back then they didn't have flow benches like today not long after that did they start to close the exhaust port down to 3/4 of the size.
I think they are working against you with the smaller cam

OK, so I guess I have two choices then concerning the engine..

1. Keep it at stock stroke but use a high .750 lift roller cam and high stall converter to get the use of flow and power from what the heads can make..

Or...

2. Build a 540 cubic inch stroker bottom end and supercharge it and with that I could use the hyd. roller cam and may be even the Dynamic 9½ converter I have in the trans now...



/Tom