700hp pump gas bbc 496

[BlackoutSteve]

no the formula is flywheel HP, - they didn't have chassis dynos in the 60s
if it was rwhp then my 420 hyd roller pumpgas SB would be makin well over 700fwhp,
and we know that aint so - it only made 641 on the dyno.
and its in a car that's not really set up for it... 373s aint helpin.

I guess that's if you believe that 30% goes missing. Maybe in a 100hp car but I doubt at that level..
Still, the formulas would have to have a huge fudge factor for all the drivetrain variables..

[67RS502]

the formula has no fudge factor, it uses the most efficient drivetrain they had at the time in stockers
they figured out how much power it took to move X weight to X mph in a 1/4 mile... their stockers proved this.
its simple physics really. you could figure the same thing for how much HP it takes to move 10000lbs 100ft in 1 minute,
as its also physics / math.

and what do you mean 30% goes missing???

I was using around 15% drivetrain loss for my 420
641rwhp x 1.15 = 737fwhp (that's if you believe the formula is wrhp, and I'm using 15% loss)
or work it backwards, 754rwhp x .85 = 641fwhp (also 15% loss)
either way my homebuilt hyd. roller 420 is NOT makin 737-754fwhp, since it been dynoed at 641.

and if my car was set up right it would run faster still, getting very close to the formula
as of now its gone 136.5mph at 3100lbs which shows 605fwhp according to the hp formula.
when I get the car set up right for the SBs powerband, it should run faster putting it close to the 641hp the engine made on the dyno.
by the way I only run it once or twice per year, so I don't get to do much tuning on it at the track... theres gotta be a bit more in tuning it. if it was a racecar spending bunch of time at the track it would be a bit more efficient.

So building a 700hp 496 should be easy to prove at the track... or should get close to the #s if its a decent setup streetcar. 10" verter 373s could back up the dyno #s pretty close I believe .
we have an honest dyno here that many have used... and the mph back it up.
the OPs BB will be dynoed and go down the track, should be around a 10.0s car.

[BlackoutSteve]

In your signature, I was assuming you meant you 490hp 383. (700x0.7=490)
But the formula would have to be inaccurate with today's drivetrains.. They would have all been 4 speeds back then too.

[vortecpro]

the HP formula came from the 60s Mopar stockers
nowadays we have
more aerodynamic cars
synthetic fluids
light weight tranys
and so on
so a cars MPH can show more HP then the engine is makin, this mostly happens with stocker type cars, but very possible.

No doubt the "losses" figured into some of those formulas has changed thru the years. But the idea is still valid, just the formula mind need a modern day up date.

Just remember one thing about the Moroso power speed calculator (which is what I go by) the MPH traps were longer when it was designed, and the type of NA cars we run every MPH is around 30 HP.

[vortecpro]

First time out after a complete overhaul of the car, the engine came off the dyno went into the car, serious traction problems caused the use of traction control, although this did not keep this setup from showing dyno HP at the track, @ 745 feet DA, this why I believe this is a great example.

The Car: 70 Camaro, 30X9 tire, running weight 3400, 505, production block, 260/260/108 solid roller, Vic jr, 1000 HP 4150, 305 AFRs.
Through the mufflers. 2.20 low turbo 400, 4.10 geared 8.5 ten bolt.

Dyno HP on SF 901 @ 29.92 60 degrees dry air corrected 821 HP
Observed HP @ the track @ 745 feet DA, 146.34 / 3400 pounds / 831.6 HP observed Stan Weiss calculator


http://youtu.be/E1Wz5qZDPAk

[CamKing]

I'm probably a bit late in this thread but here is some food for thought..
http://www.superchevy.com/technical/eng ... ewall.html
729hp on a 496 with AFR300s and low 10:1 comp.

Notice that the 255/260@.050" cam made peak HP between 6,300, and 6,600rpm, and it took a huge head to get the power above 700hp.

Please don't take this as arguing, but I don't think a 300cc head is huge for a 496, could probably have hit that number with there 290. The solid roller is what it is, any idea what it would equate to as a hydraulic? Would it be close to Vizard 's cam?

I'm just going off the info in the artical. They did not make above 700hp until they went to a 300cc intake runner.
A 255/260 solid roller is the same size as a 250/255 Hydr roller.

[CamKing]

Ok thanks for all the input. I want hdy roller not solid and I don't want to turn high rpms I want 93 octane...vortech performance built a motor for a friend of mine made close to 650 pump gas ran 10.47 best pass in old school vette with cast iron heads. Now I no its possible and I don't expect to hit a true 700hp but I would like to get close to that number.at 565hp my 70 camaro with 3.73 weighing in at 3550 lbs ran 10.89 @124.9 best pass. I would like low tens high nines.if 565hp ran high tens I'm guessing 650-700hp is where I want to be.now with out argument what's the right combo to remotely get close. I will dyno the motor at Owen's racing engine's. Then put it in my camaro and hit the track. The truth will come out

Go with 1.8 rockers, and Part# HR78360-80360-110
252/258 @.050"
.648"/.648" Valve Lift w/1.8 rockers
110 LSA

Gear it for 6,500 RPM.

[swatson454]

DV used these specs on his 700 HP, 505:

Comp SP Roller on the intake: 279 advertised, 251 at .050, .653 lift with a 1.7 rocker
Comp RP Roller on the exhaust: 284 advertised, 254 at .050, .647 lift with a 1.7 rocker
107 LSA installed on a 104 ICL

Says the heads flowed 405 cfm at .750 on the intake and .300 on the exhaust. He says the engine had "full street manners" but I also have seen his version of a "glass-smooth, 600 rpm idle" BAH ba ba BAH ba ba BAH ba ba


Shawn

[Orr89rocz]

First time out after a complete overhaul of the car, the engine came off the dyno went into the car, serious traction problems caused the use of traction control, although this did not keep this setup from showing dyno HP at the track, @ 745 feet DA, this why I believe this is a great example.

The Car: 70 Camaro, 30X9 tire, running weight 3400, 505, production block, 260/260/108 solid roller, Vic jr, 1000 HP 4150, 305 AFRs.
Through the mufflers. 2.20 low turbo 400, 4.10 geared 8.5 ten bolt.

Dyno HP on SF 901 @ 29.92 60 degrees dry air corrected 821 HP
Observed HP @ the track @ 745 feet DA, 146.34 / 3400 pounds / 831.6 HP observed Stan Weiss calculator


http://youtu.be/E1Wz5qZDPAk

Lol spot on. Seems legit to me

[prairiehotrodder]

My guess was way off on the camaro, I thought i had read that the car made 700 hp. As far as power / speed calculators I usually use the one on the pro-systems website. I'm not sure who designed it. I recently stuck a Straub designed cam into my 489 but i don't have any usefull track times yet.

[67RS502]

My guess was way off on the camaro, I thought i had read that the car made 700 hp. As far as power / speed calculators I usually use the one on the pro-systems website. I'm not sure who designed it. I recently stuck a Straub designed cam into my 489 but i don't have any usefull track times yet.

the old engine made around 570hp
with new heads, intake, cam, we're hoping for around 700hp and keeping it streetable.

[GARY C]

The engine, or any engine on a dyno is useless, unless you know how to interpret the data accordingly and how that data relates to down the race track. I see very few, if any at all, that can properly interpret a dyno sheet and how it relates down the race track. I see engines go in to dyno sessions and leave with significantly increased or enhanced intake volume (spacers, bigger manifolds, bigger carbs..ect..) and when they get on the race track, they don't run for shyt.

Here is a tip: 1. On an engine that makes around 700-900hp, stay within 18 hp for the average over a 1400 rpm curve, when comparing it to the peak hp single figure.

2. When making 1000-1300hp. Stay within 22-25hp for the averarge over a 1400 rpm curve, when comparing it to the peak HP single figure.

If you can build an engine that falls within the guidelines above, than you will go fast down the race track.


P.S. automatic trans backed engines, which applies to 99 percent.

This is from another thread here, I don't know if it's true are not.
I do feel that if the peak number is high and the average number sucks that the car will not perform...and visa versa.

[nevdos]

First time out after a complete overhaul of the car, the engine came off the dyno went into the car, serious traction problems caused the use of traction control, although this did not keep this setup from showing dyno HP at the track, @ 745 feet DA, this why I believe this is a great example.

The Car: 70 Camaro, 30X9 tire, running weight 3400, 505, production block, 260/260/108 solid roller, Vic jr, 1000 HP 4150, 305 AFRs.
Through the mufflers. 2.20 low turbo 400, 4.10 geared 8.5 ten bolt.

Dyno HP on SF 901 @ 29.92 60 degrees dry air corrected 821 HP
Observed HP @ the track @ 745 feet DA, 146.34 / 3400 pounds / 831.6 HP observed Stan Weiss calculator


http://youtu.be/E1Wz5qZDPAk

Not arguing the engine made the power it did,but what do you think may happen to those mph numbers once the sixty foot numbers go down to where they should be for the given et ?

[67RS502]

Brian Gooding, Blue66 on most boards. Never dyno'd, 1966 Chevelle, pump gas 496 10.5 to 1. Run's 9.89

CrazyDavey Racing, 509, 11.3 to 1, Dyno'd 763HP and 732#/ft, 3650# best run 9.40 at 141MPH

thats why youre doing the cam on this one Chris!

[67RS502]

I'll ask this, how about when you don't believe the dyno numbers but the car runs the numbers that it should? What then?

you better believe it