426 Hemi build up, What to do???

[bigj3341]

I just got my hands on a 426 hemi. Im very excited as would most people. I do not have a car to put it in though. I know these are powerful motors stock and built up. I am wondering though how i should go about building this thing. I ran in the car i took it out of and sounded pretty good for over 200k miles(suposedly). I want to build it up to me a monster. I dont know what to do though, im not experienced with hemi's other than stock rebuilds and tune ups. Please let me know you ideas.

As to what ill put it in i am working on that. I would like to put it in a challenger if i can get my hands on one. Worst case ill put it in my charger. lol

[tenchu80]

I would contact enginemasters.com. They've covered just about every type of motor build up at least once.

[DartGT66]

What kind of use will it see? Do yuo want it to remain close to stock externally, or are you ready to go with high single carb intakes etc? How much money are you willing to spend? But assuming this will be mostly a street car, I would aim at as much cubic inches as possible, with light internals. Aftermarket 4.25" stroke crank, long rods and forged custom pistons, at .060" oversize you would end up with 496 cu in. Some head work, camshaft for your taste, and the induction & exhaust in order, and you should get easy 600 hp with great torque on pump gas, or more top end power with a bigger carb, but little less low end.

[bigj3341]

Money no object im going to work on it overtime no big hurry. I can buy parts as money is available. Use is going to be at the strip and street use once in a while. I would like more than 600 hp. If i build it i would like to be able to do the pump gas drags and be completely street legal. Hot Rod magazine did a pump gas drag and a Hemi charger got 2nd. I believe it was 570+ inches now i dont want to go that much but i would like to get my charger if i use it to run mid to high 10's with the hemi.

[DartGT66]

To run well in the 1/4 mile, you need a good chassis. With a good chassis you should be n the 10's with 600 hp. If I remember correctly, the 572 hemi charger was 7th in the first pump gas drags? Anyway, a very good way to get a lot of power while retaining streetability is to add some boost. It's also most likely the least expensive route to get considerable gains.

[OHD]

I would like more than 600 hp.

You can get that with just good heads, valve train, and exhaust system on a stock engine.

If you want more:

Heads 1900-2300
Rockerarms 1200-1500
Shafts 250-450
Stands 300-700
Porting 900-2500
Valves springs retainers keepers 450-1800
Valve covers 400-1200
Exhaust headders 550-1000
Carb 550-1000
manifold 650-1500
cam and lifters 550- 850
Machine work 1200-1500
Engine assembly & tune 1000-2500
Misc stuff 300-1500

Stock rebuild should run 3500-7500 good for 550-600HP, it would be way over the heads of many engine builders to attempt and out of your range. Try BG racing in PA for a good start for the rebuild. Cheap and Hemi are not mixable and will not coexist.

I think there is a lot of dreaming in this OPs post....

[rampage_82]

Make it a 496, you won't be sorry....

[MOPEkid]

Wow, that's cool. Why would rebuilding a Hemi be way over the heads of most builders? Are they that much different from normal big-blocks? I think Hemis are really cool, but it bugs me every time I look at those huge quench-less chambers and giant piston domes. I like the design of the new (3rd gen) Hemi heads better.

[PistolGrip440-6]

If you want 10s it can be done with cubes in the upper 400s and be driven on the street. 426 might do it but it'll take alot of cam. Ive never owned my own Hemi or raced it, but Ill share the little bit of knowledge I have.

The heads: Unless you really know what youre doing, DONT touch them. Let someone who knows Hemi heads do the work if you have any, because they were designed very well from the factory and by changing the shape of the port where it turns to meet the valve opening can hurt flow very easily from what I understand.

They like cam, and alot of it. They flow good at high lifts so get them on a flow bench if you can and pick a cam with as much lift as they like! A roller cam would obviously work best.

Thats about as much advice as I can give thats not obvious to any engine build. For an intake, I personally like a cross ram but a tunnel ram could and probably does work better in most applications, especially if you want to wind it out. Build it right, tune it right, and drive it like you stole it! Hopefully it puts your head into the back seat! I hope I can get my hands on one soon. Lots of work aheadbefore that though haha.

[73charger528]

you want 10s find a 68 dart or barracuda .

there was a street racer from here 15yrs ago running flat 10s with a 68 barracuda with a 500cid wedge with b1 heads in street trim.

he was known as king of the gate around here he would only race for $500 or more.(illegal street race that is)

he drove this thing to the track once he blew my friends mind. my friend had a race only 68 camaro running low 10s in the bracket program he went up against this guy and got his a## handed to him by a street car.

The guy still owns that cuda its been upgraded to hemi power its no longer a street car but it runs 8s now.

for a engine builder I would contact ray barton they build a lot of hemis for the s/s cudas and darts.

[Paul Precht]

Two words of caution, The 5/16 valves are a huge weaklink,and when they break, they take out a lot with them. Valve to valve clearance is a major issue when dealing with a large cam. You can't slapp a big cam in and go. Valve to valve clearances must be checked with a feeler guage with the cam, heads and valvetrain in place, paul.

[dave571]

I think you'll need more than 600 hp to run 10's in a full bodied, B body.

More like 700 at the engine.
A quick hit on this calculator http://www.fastcoolcars.com/hp_calculator.htm
Shows about 675 crank and 540 wheel

That's fair bit.

Just make sure you are aware of what you are diving into.

Big cam, expensive valvetrain parts, possible stroker kit stuff.
A lot of 727 internal upgrades if you don't want it coming up through the floor, and a dana, or a well build 9".

I would think 20 to 30 K would be realistic by the time you build the trans, diff, and motor.

Just food for thought

[bigj3341]

Originally Posted by dave571

I think you'll need more than 600 hp to run 10's in a full bodied, B body.

More like 700 at the engine.
A quick hit on this calculator http://www.fastcoolcars.com/hp_calculator.htm
Shows about 675 crank and 540 wheel

That's fair bit.

Just make sure you are aware of what you are diving into.

Big cam, expensive valvetrain parts, possible stroker kit stuff.
A lot of 727 internal upgrades if you don't want it coming up through the floor, and a dana, or a well build 9".

I would think 20 to 30 K would be realistic by the time you build the trans, diff, and motor.

Just food for thought

I have a 9" that is heavily built up for nss racing out of a friends old car not narrowed i would have to move the perch's but thats it. The 727 i have about 3 laying around all rebuilt but onlky stock. I have a transmission guy that is excellent and has built 727's for pro/super stock. So those are covered

I was worried with the heads. I don't know anyone who does hemi heads. Most shops around here wont touch them and the others i dont trust. I figured if i ran it in my 69 charger(close to 4000# curb) i would need damnn near 700 hp. If not more and thats barely street-able. I should of said street being getting it to a local racepark about 6 miles away and local cruises. I dont like to trailor i like to drive. The one in Hot Rod (68) was 572+ cu in and 900 hp with stock suspension an mostly stock car just stripped down a lil bit interior. It got 2nd place(beat by a ws6 trans am 03') but i know the guy that owned it and he had a good 60k+ in that motor. I dont really wanna spend that much. I would like around 700 hp and stock suspension as well and ill take whatever et it runs.

[dave571]

Isn't Ray barton a Hemi Guru?

Im' also wondering if Indy sells hemi heads.

[MOPEkid]

Yes, Indy makes a line of Hemi cylinder heads with the "Legend" name. They CNC-port them and do all sorts of other things too.

[DartGT66]

Originally Posted by dave571

I think you'll need more than 600 hp to run 10's in a full bodied, B body.

More like 700 at the engine.
A quick hit on this calculator http://www.fastcoolcars.com/hp_calculator.htm
Shows about 675 crank and 540 wheel

That's fair bit.

Power helps achieving the goal, but NHRA Stockers run deep in the 10's with way less than 600 hp, so you can do it with a good chassis and drivetrain. My old car run 10.51 with a pump gas wedge weighing 3600, through four muller exhaust, 275/60/15 radial tires and 3.23 rear gears,that's still in hte 10's even with 4000 lbs weight. Our street C-body run 10.61 in the 1/4 with the same engine, DOT tires and with less than spectacular drivetrain, using only first and second gear . Now, it runs 8.4's, still with basically the same wedge and on pump gas and DOT's, but that's another story.

Modern Cylinder Heads should be pretty good at prepping Hemi cylinder heads, doing also Super Stock and Stock Hemi heads. http://www.moderncylinderhead.com/ He can also supply you with a good cam, and deven help with other parts choices.

A street car is usually somekind of a compromise between drag and street properties. Going with most cubes you can get with more stroke is benefical in many ways, it will move the engines power band in to lower rpm, which means that your valvetrain doesnät have to support extremely high rpms, and you have power to move the car even with less tahn perfect converter/rear gear combo. In todays world, the 426 hemis intake ports are pretty huge. With only that much displacement it makes the engine a high winder by nature, with less than specatcular low end. By increasing the displacement, you make the velocity of the heads suit the engine better.

Here is some of our pump gas streeter videos for motivation.
10.51/133 mph/1600 lbs/528 wedge 440-1:
http://www.youtube.com/watch?v=328VI...eature=related
9.44/144 mph/3230/499 wedge B1 lbs:
http://www.youtube.com/watch?v=xzDOhnGdk6U
8.41/162 mph/3670lbs/477 wedge 440-1:
http://www.youtube.com/watch?v=Y9cp72qNFG8

[bigj3341]

Originally Posted by DartGT66

Power helps achieving the goal, but NHRA Stockers run deep in the 10's with way less than 600 hp, so you can do it with a good chassis and drivetrain. My old car run 10.51 with a pump gas wedge weighing 3600, through four muller exhaust, 275/60/15 radial tires and 3.23 rear gears,that's still in hte 10's even with 4000 lbs weight. Our street C-body run 10.61 in the 1/4 with the same engine, DOT tires and with less than spectacular drivetrain, using only first and second gear . Now, it runs 8.4's, still with basically the same wedge and on pump gas and DOT's, but that's another story.

Modern Cylinder Heads should be pretty good at prepping Hemi cylinder heads, doing also Super Stock and Stock Hemi heads. http://www.moderncylinderhead.com/ He can also supply you with a good cam, and deven help with other parts choices.

A street car is usually somekind of a compromise between drag and street properties. Going with most cubes you can get with more stroke is benefical in many ways, it will move the engines power band in to lower rpm, which means that your valvetrain doesnät have to support extremely high rpms, and you have power to move the car even with less tahn perfect converter/rear gear combo. In todays world, the 426 hemis intake ports are pretty huge. With only that much displacement it makes the engine a high winder by nature, with less than specatcular low end. By increasing the displacement, you make the velocity of the heads suit the engine better.

Here is some of our pump gas streeter videos for motivation.
10.51/133 mph/1600 lbs/528 wedge 440-1:
http://www.youtube.com/watch?v=328VI...eature=related
9.44/144 mph/3230/499 wedge B1 lbs:
http://www.youtube.com/watch?v=xzDOhnGdk6U
8.41/162 mph/3670lbs/477 wedge 440-1:
http://www.youtube.com/watch?v=Y9cp72qNFG8

I have an idea of how im gonna do this. The key seems to be in the heads as with any motor almost. I have heard though the biggest cam is not the best for a hemi?true?. I would probably bore it 30 over high comp pistons from keith black, gear drive,get the heads really worked over.

1. what kind of intake carb setup?
2. how big of a cam?

Like i said im not familliar with these motors other than stock.

Charger is stock mostly, stock torsion bars, superstock springs, just two bucket seats, shifter, 8 3/4 with 3.73 gears, discs up front from a 73 dart. Aluminum rad. Biggest mods being fiberglass fenders and hood. Ideas??? Sound good for the hemi's home

[DartGT66]

The key is not necessarily in the heads (alone), it's in the package. The parts chosen must work together, and the drivetrain must support them. That's why I mentioned increasing the displacement. The ports in 426 Hemi heads are pretty big, for good port velocity you should turn the engine at very high rpm, and the pump gas + the required low CR are kinf of against it. With more cubes, you also need less dome in the piston to achieve acertain performance level, and a shorter piston overall considerable weight savings there. That means less wasted energy, and less stress for the rods & crank. I wouldnät go with off the shelf hypereutectic pistons, if that's what you mean by KB pistons. I would by forged lightweight pistons, that suits your needs. The carb/intake set up really depends of what you want. A single plane dominator intake, like one from Indy or Barton, is simple, works well and can support a lot of power. For power, even with pump gas, you need a pretty big cam. I would go with a roller, simply because you don't have to worry about the berak in and such. If you go with about 500 cu in, I think the CR should be about 11:1 and the cam at about 270 degrees at .050". With that kind of combo, the peak power might be at around 6500-7000 rpm possibly making 700+ hp with still driveable low end torque. Hemis like big cams, the design just have to be a bit different to wedge grinds, usually wider LSAs and less overlap (partly because of the forementioned situation, the valves can actually hit eachother). I think the true weight of your charger, the way you described it, will not be 4000 lbs even with the hemi. Of course, you have to add a rollcage to be able to race, and subframe connectors are a must. They add some weight, but still I think you should be able to get to around 3700. Look at our C-body, it's 3670 lbs with driver, all steel except fiberglass hood and bumpers, and it's got a 12 point mild steel cage, heavy Dana 60 rear etc. 3.73 gears will be too long for best performance, but may aork as somekind of a compromise with a good 9.5" converter. SS springs can be made to work pretty well, use good shocks for adjustments. Cal-tracs with mono leafs would be better on less than perfect surfaces, and still easy to put on. The 8 3/4" rear axle overall may get in to trouble, with that kind of power and weight it will live on the edge.

[OHD]

The most efficient way to bild a car to handle the power is to start with the car on an alignment jig. Align everything FIRST...

Centerline the drive train where you want it and build from there.

On one of the Bel IIs the right rear frame was so far off from the factory it had to be removed aligned and reinstalled prior to setting up the suspension.

We centerlined all 1.25 to pass and went from there. 16K later we had a rolling chasiss with rear and suspension set, installed, and done, engine plates and reinforcements installed, all interior sheetmetal tacked in, roll cage done, and ready to start on finish welding, the engine, and trans.

You are much better off dealing with a company that knows the setups and process or you will be chasing your tail repairing a cobbled up system. We chose ladder bar/coil overss for flat out stright line, or you could go 4 link with tubbing or mini tubbing.

Its only money and anything having to do with overall reinforcement for that power level is going to take extensive modifications that should be done by expirenced professionals, to last.

I am speaking from real time actual expirence, not second hand information.

Go to a cage shop and just look at some of the stuff they have to "repair" and you will get a better understanding.

We can jack on any corner and lift 3 wheels off the ground in a very short amount of movement. We can jack on the centerline and lift one end up equally with ease.

We have to drop the rear to change the rear tires so the "cage and reinforcing setup" makes it a piece of cake.

Have a realistic budget set aside add 20% or you will end up selling your "project" when you run out of money. Then you will REALLY learn what non professional work is worth.

[OHD]

After we did the chasis the brake system to stop the beast was another 4800.

[OHD]

BTW: if you do not plan on turning the engine 7500+ you are better off building a wedge, for the hemis DO NOT COMPLETELY come alive until high rpms.....where the heads and their flow show their real true gains.

[dave571]

Originally Posted by DartGT66

Power helps achieving the goal, but NHRA Stockers run deep in the 10's with way less than 600 hp, so you can do it with a good chassis and drivetrain.

Well, I'm going to respectfully say that's a crock.

Sorry, but that is typical dragracing folklore.

Every guy who runs 10's or faster likes to downplay that the car is practically stock, or is far less radical than it really is.

Say what you want, but there's no way 4000 pound cars run 10's on less than 600 hp. It's simply not possible. The laws of physics agree with me.

I've seen you give good advice on this board plenty of times, and your cam and head recomendations are right on the money for this combo,

BUT you need power to go fast. The ET proves the power is there.

Merry christmas to all, and bigj3341 I hope the engine works out well.

[DartGT66]

I have never been in tens with only 600 hp and 4000 lbs, but those Stockers do run amazingly well with relatively little power. Maybe not quite in to 10's with 600 hp and 4000 lbs, but shouldn't be that far. Our "best" achievement is the 4 D sedans 10.54/129 mph weighing 3500 lbs, 3.91 gears, 10.5/26/15 ET Streets, 8" converter and the3 451 wedge dynoed 649 hp. Other than that, we haven't quite been able to run according to the dyno numbers at the track.

[Paul Precht]

My somewhat out of date and no frills A/SA 63 Ply stocker ran a best of 10.68 on an 11.30 index at 3550 lbs with driver, 3490 is the minimum. On that pass I estimated the motor was making about 575 HP at the crank. A street car is not as efficient and one weighing 4000 lbs would require close to the 700 mark to run mid to high tens.