Alright guys, I've been putting together a build for the past few months and I was hoping some of y'all might be able to chime in on what kind of numbers I can expect. Here's the specs:

470 shortblock from Indy Cylinder Head (400 block/offset 440 crank)
10:1 compression
Stealth heads CNC ported with a valve job
hughes hydro/flat tappet cam: .592 int/.606 exh, 242* int dur/246* exh dur at .050, 108*lsa
Crane 1.6:1 ductile rockers
holley street dominator intake
1 7/8" primary full tube headers
2.5" dual exhaust with x-pipe

This build is going into a 1971 Charger, with a 727 auto, turbo action 2800-3000 converter, 3.91 8.75 sure-grip rear, and 275/60/15 rear tires.

Assuming I have and adequate fueling system and ignition system, what kind of horsepower/torque numbers and quarter mile times are y'all predicting?

My guess would be around 525 to 550 hp. Ron

I had a very similar combo in my 73 charger.Dynoed at 525hp and 570tq.I was running edelbrock heads(not ported).I got my best numbers with a 1" tapered 4 hole spacer on top of a 1" open spacer with my 750 holley hp.

What carb. size and brand , same thing on the rear tires? It do make a difference

A 470 with a flat top and 80cc chamber should get you closer to 11to1. I know you're not asking for advice but if you don't already have the parts the cam could use about 10 more degrees. And if you bought and indy shortblock I would do a teardown and have it all checked out. I was hoping someone else would say it. A little more stall would be good too. As is I would also guess around 550hp.

Thanks guys, I appreciate the input and advice.

I've been stressing over the cam selection ever since I started looking at this build, and I did a ton of research before I finally made a decision. The general consensus that I came up with when choosing a hughes cam for a stroker motor was to go on hughes and pick out a cam that is suitable for a stock-stroke engine with the same combination and then go a size or two bigger, so that's what I did.

Do y'all think it'll turn out to be under-cammed?

As far as converter goes, this is going to be a 95% street car, with trips to the track made every now and then when I get the chance. Keeping that in mind, I didn't want to go too radical with the converter.

Now for the carb...

On the old 383 magnum in the car, with headers, intake, and a re-curved ignition I was running a re-jetted Quadrajet carb. Dad has a warmed-over 440 with a Q-jet and we've had really good luck getting decent power and great fuel mileage out of these carbs, plus they're really simple to tune. So for this engine, I'm gonna try and just re-jet the Q-jet and see what I've got. For primary jets I'm running a similar size to that found on a '70 RAM AIR 455 GTO, and for secondaries I have the next set up from what was found on a 500 Cadillac.

If it turns out to be too lean I've always got more options on rods and jets, and plan B is an 800-850 holley.

Thoughts?

Thanks

I think that cam is just fine and well-matched to the rest of the combo. If you want any bigger you could opt for the Comp XE 251/257 @.050. Once you get over ~252 on a Hydraulic flat tap on the intake you're usually better off just going to a solid. The SD is a great manifold but maybe for your combo a performer RPM and square bore 800-850 may give you a tad more off idle/roll on torque. The Eddy avs 800 works very well and generally can get better cruise MPG than a holley, Q-jets can be magic if you know how to tune them, I had an awesome Brad urban Qjet on a 10.5:1 455 olds that I dropped in a 77 Caddy Seville sleeper many years back.


I'd run a fairly tight 9 1/2" or 10" PTC or T/A converter, something that footbrakes to ~3000-3200 but tight enough not to feel at all slushy at part throttle in a heavy B body.

Overall you have a very good, and well thought-outrecipie for a 535-550-ish horse pump gas motor. You didn't get hung up chasing high RPM power when what you really want is a ton of face distorting mid range torque, it's really what the 431-470 inch motors with standard sized ports do best, and they do it very well.

Thanks for the advice on cam and carbs.

The reason I'm going with the SD intake is that I already had one on the 383, so I figured I could save a buck or two by just using that. Same with the carb.

Thank you Streetwize for the kind words regarding the build... Being 21 years-old and on my first real solo build, its good to have some reassurance coming from someone with as much experience as y'all


Just so y'all know, the build is just about complete and hopefully I'll get it running strong this weekend. Do y'all think 11's are out of the question?

Its got enough for 11's. My old combo was a stock stroke 440 with 906 heads , the MP .557 cam , Street Dominator intake , 850 DP , 1-3/4" headers , 4.30's and 30" tires with a Dynamic 9.5 converter flashing about 4200. At 3700 lbs it ran a best of 11.49 @ 116. I think you will have a stronger eng then that was but your Charger might weigh a bit more then my 63 but not much more. Ron

With Drag Radials and decent weight transfer you should easily go 11.80's or maybe a little lower, first time out probably very low 12's.
Start out shifting about 5600, tune for your plug readings and up the shift points 200 until it starts slowing down.

Try to tune your launch as well as possible before going to the track, make sure you've got enough pump shot to pull you until the mains kick. One of the biggest issues tuning a heavy car.

For a street car don't remove your sway bar but take as much preload out of the end links as you safely can without it being 'sloppy'. Lube the mounting bracket bushings with Lithium grease an make sure they don't bind. Make sure your rebound and jounce bumpers are all fresh and you have a good allignment on the car.

As far as weight goes, I haven't been able to put it on a scale but here's some thoughts to ponder. Figures put a stock big block 1971 Charger at about 3900 lbs.

I'm in the process of putting her on a diet, including:
aluminum heads
aluminum intake
mini starter
fiberglass hood
lightweight front racing seats
removing all the air conditioning components
replaced heavy hidden headlights with lighter exposed units
lightweight insulation
headers (dont know if that saves any but cast iron manifolds sure are heavy)


That's the start, I'd like to get it down around 3500 but I realize that's a pretty ambitious goal. The good news is my 135lbs wont contribute much to the race weight

It should go mid 11s.

Also your cam is just fine. I thought I read challenger but its a charger. Focusing on torque is gonna be very helpful. I wouldn't change anything at the point you're at. Just get it together and go from there. For carburetion my favorite carb has always been a holley 750hp. But different people have different preferences.

somthing to think about as far as the carb goes.. the qjet as awesome of a carb as they are.. it is plauged with a small float bowl. if you do use it check out jim hand's pontiac stuff. there is a lot of low pressure tricks etc. to make them work. he's got a million pound wagon in the deep 11s

The motor won't be under-cam'd with the 1-7/8" headers. I have only a little bigger of a cam (.607 lift) in my 511ci and I run 11.50's leaving soft (stock axle shafts) in my street car.

Btw, I have 1-7/8 hookers and 2-1/2" exhaust and ran the 11.54et w/3.55 gears.