[carsavvycook]

Originally Posted by beaker60

Honestly,,I don't know,,what I do know,is that I was part owner in a Nascar series Late Model Monte,the engine was built by a very reputable builder in Centralia Wash,the other partners and I watched him build that engine over a period of about 4 months.The goal was 575 to 600 HP,once he got to around 400,then the work began.He has his own dyno room and he would install parts,dyno,change parts,dyno,and after some very expensive parts had been installed and a lot of testing,he finally reached about 625 HP.What I'm trying to say is that it didn't just happen with the turn of wrench under the shade tree,he had to work at it.So I think a lot of claims of high HP is probably a lot of dreaming.I have a pretty healthy small block,but it has been built on a very tight budget,it doesn't have titanium valves and a 38LB stainless crank and all of the other goodies that could produce that type of horsepower,so unless he can show the receipts for that kind of HP,,,don't buy it.

In a 'nutshell', If you do not have a 1-1 ratio, or close too, from the engine HP to the drive wheels at the advertised HP/Torque ratings, you will not have the same 'Dyno' readings, and finish 'behind' the leader.

"Advertised" and "Actual" results will vary with vehicle weight(mass), and "Gear Ratio's". It takes a lot of money and time to design and build (like quoted) an engine, or vehicle, to perform to between 'As Advertised, and Engine Dyno specs'.

[beaker60]

The other part of this also is,in racing that is,is once you have the horsepower,then you have to get it to the ground,and keep it there,we had an engine tech,a chassis tech,a tire tech,,,all of these things have to be applied to shave a tenth of a second off your time.You can have a 1000 horsepower,but if you don't have everytrhing else dialed in,,,so what???I admit,,it's great to be able to say you have all of that power at your command,but it has to be directed.My little S-10 has around 450-500 HP,,and that's on a budget,but what I have it tied to at the momment doesn't do it justice.I know that my next improvement is going to have to be the gears and the tranny,until I get these things straightened out,,,all it is,,,is just a good street rod and not a competitive race machine,,but all in good time.I'm still having fun with it.

[curtis73]

If you're talking about a ford windsor, or a small block chevy, or a mopar LA, then you have to consider that they are ancient designs that were last updated in the mid 90s. Updated heads on an engine architecture that was created in the 50's is one thing.

But, then when you see a 6.0L LS7 that makes 505 hp from the factory, passes rigid ARB emissions standards with no EGR, and returns 25-30 mpg with a silky smooth idle, that's a whole different ball game.

Comparing a 302 windsor to something that is produced today is like comparing a flathead to a muscle car motor.

It all depends on what has been designed for the engine to update it. I'm currently looking at spending thousands of dollars updating my 96 LT1 to a 383 stroker, CNC ported heads, a modern cam, and a ported intake. I'll be barely squeaking by the 12-year old easy smog test with 400-ish HP. I could also just drop in an LS1 with a couple bolt ons and get that same power that passes more stringent emissions tests almost transparently.

Technology really has come that far.

[carsavvycook]

Originally Posted by beaker60

The other part of this also is,in racing that is,is once you have the horsepower,then you have to get it to the ground,and keep it there,we had an engine tech,a chassis tech,a tire tech,,,all of these things have to be applied to shave a tenth of a second off your time.You can have a 1000 horsepower,but if you don't have everytrhing else dialed in,,,so what???I admit,,it's great to be able to say you have all of that power at your command,but it has to be directed.My little S-10 has around 450-500 HP,,and that's on a budget,but what I have it tied to at the momment doesn't do it justice.I know that my next improvement is going to have to be the gears and the tranny,until I get these things straightened out,,,all it is,,,is just a good street rod and not a competitive race machine,,but all in good time.I'm still having fun with it.

This is my opinion, what's his!

[Silver Shadow]

Originally Posted by carsavvycook

In a 'nutshell', If you do not have a 1-1 ratio, or close too, from the engine HP to the drive wheels at the advertised HP/Torque ratings, you will not have the same 'Dyno' readings, and finish 'behind' the leader.

"Advertised" and "Actual" results will vary with vehicle weight(mass), and "Gear Ratio's". It takes a lot of money and time to design and build (like quoted) an engine, or vehicle, to perform to between 'As Advertised, and Engine Dyno specs'.

How do you figure that ?????

100 foot pounds and 4,000 rpm = 76.16 Hp

Feed that through a 4:1 (zero loss) gearbox and you get

400 foot pounds and 1,000 rpm = 76.16 Hp

I am not even going to ask how engine power varies with vehicle weight.

[Silver Shadow]

Originally Posted by curtis73

But, then when you see a 6.0L LS7 that makes 505 hp from the factory, passes rigid ARB emissions standards with no EGR, and returns 25-30 mpg with a silky smooth idle, that's a whole different ball game.

Comparing a 302 windsor to something that is produced today is like comparing a flathead to a muscle car motor.

technology really has come that far.

It sure has !!

Not only has the power just about doubled, but the weight of the engine has dropped by around a third as well.
If it is going into a very light weight body, the engine weight drop is almost as significant as the power increase.

[sam-missle]

Originally Posted by carsavvycook

Take a 'horse' with a 125lb rider, and a 'horse' with a 300lb rider. Which 'horse' will win the race?

Chill out.

As silver shadow said horse power is a simple measurement, the horse with different weight riders is considered as power to weight ratio.

sam-missle

[carsavvycook]

Then why did he post this?


[/QUOTE]Why would you want to do that ????

A dyno measures rpm and torque, and calculates horsepower. That is all it does.

Vehicle weight and gear ratios have absolutely nothing to do with measuring horsepower.[QUOTE]

[Silver Shadow]

You measure engine power on a dynamometer. Vehicle weight has absolutely nothing to do with how much power the engine can produce. In fact you can measure engine power without even having a vehicle.

You measure vehicle weight on a set of scales. A vehicle weighs what it weighs, regardless of what type of engine it has. It may even have no engine at all,

So you have a power measurement
And you have a weight measurement

The final performance of the vehicle depends on both.
But both are quite independent.

Does that help ?

[carsavvycook]

Originally Posted by Silver Shadow

You measure engine power on a dynamometer. Vehicle weight has absolutely nothing to do with how much power the engine can produce. In fact you can measure engine power without even having a vehicle.

You measure vehicle weight on a set of scales. A vehicle weighs what it weighs, regardless of what type of engine it has. It may even have no engine at all,

So you have a power measurement
And you have a weight measurement

The final performance of the vehicle depends on both.
But both are quite independent.

Does that help ?

Yes!

But (I still believe) the weight/gearing ratios requior more HP to move more 'mass' down the road. I am not 'sold' yet on your theory.

[Silver Shadow]

Sure, more power is required to move more mass (at the same rate) no argument from me there.

That is why power to weight ratio is probably the most important factor in estimating performance.

[carsavvycook]

Originally Posted by Silver Shadow

Sure, more power is required to move more mass (at the same rate) no argument from me there.

That is why power to weight ratio is probably the most important factor in estimating performance.

Do You meen HP?