HOW much HP do i have
my motor is a chev 305 HO with HEDMAN headers
403 heads and cam and intake manifold
thanks
I have not drove my car with the new motor

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C man
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motor was 2.8L now it is
a 305 H.O. with headers,
403 heads and cam, intake
manifold

 

That depends on your compression ratio, camshaft, head work, valve size, rocker ratio, intake manifold, header size and about 4,999 other variables.

------------------
The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

my headers are 2"
I want a hp ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????


------------------
C man
-----------------------
motor was 2.8L now it is
a 305 H.O. with headers,
403 heads and cam, intake
manifold

 

the stock HO motor with carb made 190 hp in 86'

 

These are very difficult, if not impossible questions to answer. Truthfully, nobody knows the REAL HP your engine is producing. And if they say they know, it is a "guess-ti-mate" at best. If you took your car to the race track and got your exact weight, it is possible to calculate an approximation of HP based on ET and your trap speed. But it too is only an approximation.

But, if you REALLY must know, there is only one sure fire method that I know of, DYNO.

Hope this helps.

 

I don't think the horsepower is going to matter because if you have 2" headers on a 305 you're going to run so lean that your pistons will melt.

Let me be the first:
>
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------------------
The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

2" headers? Are you sure? 1 7/8" is about the largest I have seen used on a SBC and that is on a radical motor of 400+ c.i.

No offense, but you wasted your money and probably producing less HP than a standard 305. 1 5/8" headers would have produced more torque and power for you.

 

the header were free
they are 1 7/8"
and the motor was a $ 100

------------------
C man
-----------------------
motor was 2.8L now it is
a 305 H.O. with headers,
403 heads and cam, intake
manifold

 

What's a 403 head? Do you mean the 416 casting? Before you ask this question, you need to make a few more things clear:

1) Intake: What kind of intake?
2) Cam: What's the profile? What's the installed intake centerline? Duration? Lift? Lobe separation?
3) Induction: Stock air cleaner or open element?
4) Heads: 403. What is that? What's the combustion chamber size? Valve size? Etc? Any porting been done??

We need to figure out the compression ratio.
An even better indicator is what kind of MPH your car hits at the finish line of the local drag strip.

Using the current information, we could only guess that your horsepower probably falls somewhere between 140 and 280 horsepower.

For instance: My T/A with 305 H.O. runs 14.04 seconds at a little over 100 MPH. Nearly 101 MPH, really. Thus, I estimate that its output is right around 275 horsepower to 285 horsepower, most of which is on the top-end of the power band, above 3500 RPM.


------------------
Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
New best E/T! 14.039 at 100.82 MPH in 41 degree air at Stanton, Michigan.

 

I posted this here some time ago...
you guys told me about 330 something hp
Sent it to edelbrock and they told me over 420 hp...

you see, its very difficult to evaluate.

- 1974 350 block
- 4 bolt main
- 0.040 over
- All new bearings
- All new Fel-pro gaskets
- Flat top pistons 10.5:1 comp
- Edelbrock performer RPM camshaft
- Edelbrock performer RPM lifters
- Edelbrock performer RPM intake
- camelback heads; 58cc, 2.02 in valves, 1.6 ex valves, fully ported, enlarged spring seats, double springs
- Crane 1.5 full roller rockers
- High pressure oil pump
- Weiand water pump
- Carter high volume fuel pump
- new ACdelco spark-plugs
- Taylor 8mm spark-plugs wires
- Custom HEI distributor
- Crane fireball coil
- Crane fireball H-6 ignition box w/ rev limiter
- K&N 3" air filter
- Headmen headders 1 5/8 primaries
- Mac 3" CatBack exhaust

 

You mention the "camelback" heads... all of those that I know of were 64cc more or less. With those heads and a flat-top 350, the CR is about 10.3:1. With 58cc heads the CR will be much higher, around 11.2:1.

Except for the CR, this is basically the exact setup Edelbrock rates their RPM package with. So whatever they rate that package at should be in line with what your motor will do, except that your headers are slightly smaller. That will cost you a couple of HP by making your torque curve begin to fall off at a slightly lower RPM, though your peak torque should be about the same.

Your CR is too high for pump gas. You will definitely have pinging and other related problems, and will have to back the timing off, and will only achieve that HP and torque with racing gas.

When you get it built, post your dyno results or track times. Let's see if the package "performs" as advertised, and let us know how you like it as far as how it drives.

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"So many Mustangs, so little time..."

 

forgive me, maby im just ignorant... why would header size cause him to run lean?




[This message has been edited by mtx28 (edited November 08, 2000).]