Typical power for L24 engines??

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powerslide91

New member
I am shopping around for a '70 to '73 ITS Datsun. If the engine has been 'built' and there is dyno info avalible, what kind of power and torque levels should I expect to see for a 'great' engine verse a 'good' engine?

Thanks!
Jeff
 
Originally posted by powerslide91:
I am shopping around for a '70 to '73 ITS Datsun. If the engine has been 'built' and there is dyno info avalible, what kind of power and torque levels should I expect to see for a 'great' engine verse a 'good' engine?

Thanks!
Jeff
Click to expand...
 
Originally posted by powerslide91:
I am shopping around for a '70 to '73 ITS Datsun. If the engine has been 'built' and there is dyno info avalible, what kind of power and torque levels should I expect to see for a 'great' engine verse a 'good' engine?

Thanks!
Jeff
Click to expand...

Good question Jeff.
I to have wondered this.
Reported RWHP that I have been privy to has varied on winning cars 145-164....most likely has to do with different dynos,temp,gear ratio,humidity,along with what one is able to believe.

david spillman
 
Is this question for an IT legal engine or just a 70-73 L24 in general?

You can break 1:42 at Road Atlanta with 165 at the crank, SAE calibrated (East Coast horsepower).

If all you have is chassis dyno then you really don't know what you have. They're next to worthless for comparing different cars on different days.

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katman
 
I probably should keep my mouth shut, don't want to give away my speed secrets, but a chassis dyno data is not worthless. I have a hard time believeing that engine builder dyno data is any more acurate especially between different builders. I can answer better to the chassis dyno. They are excellent for A-B runs. You don't have to pull the engine to get your data. They will measure powertrain losses. This helps you convert that rear wheel HP to engine HP. They now have the capability to measure Air/ Fuel across the whole RPM range using a WIDE BAND O2 sensor. Great for those programable computers we all can now use in IT. I have seen O.E. manufacturers bring preproduction cars to the local shop for testing and to do A-B comparisons of parts. Our company has used the dyno's for development of exhaust systems. I know of a SRF team that used the dyno to confirm the rated output of the spec engines. I believe many NASCAR teams have bought chassis dynos (Dynojet). And we all know how leading edge NASCAR is. That is just some of my high points. Of course like a computer, the tool is only as good as the guy running it. A chassis dyno is not strictly "plug and play" like some think. If any body has questions I'll try to answer them.
 
For what its worth I'll give you my HP. My car is a fuel injected ITS 280Z w/4:11 R200 rear end. I have a newly rebuilt Rebello engine in it. I didn't get to dyno the car until I had 3 races and blown 2 head gaskets (My fault not the builder). It measured 165 HP max. at the rear wheels. Assuming 15% powertrain losses (forgot to measure it on the dyno) that's 195HP at the crank. Rebello claims 210 engine HP for the F.I. Z car and 200ish HP for a Carb 240 Z car. Since I've blown head gaskets and I know I'm down some on compression the Rebello numbers seem believable. I used the dyno time to optimize timing and fuel pressure. We found that the car was slightly lean at higher RPM's so we turned up the F.P. I also know that the car is all done around 6,000 RPMs. In the end we found 5 HP from my best guess setup. With some more time, I know there is a few more HP to be found.
 
Yeah, sure, a chassis dyno measures hp at the wheels, which makes it impossible to come up with a real number at the crank. Too many additional variables which render it useless for different car/different day comparo's like I said.

Some engine builders inflate their numbers, or "miscalibrate" their dyno's, and Rebello's claim of 200hp for a carburetted L24 in ITS trim is perfect proof of that.

Bottom line is you can't believe anything when it comes to hp quotes.

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katman
 
Guys,

Thanks for all the info. I realize when you go onto a racing forum and ask "how much power ya got?" folks tend to not be inclined to speak up
wink.gif
I was just looking for some rough values to help me evaluate the claims some guys have made.

Tony, I am in Austin Texas, but would be willing to travel for the right car. If you like, my email is [email protected] if you have some info you would like to send over.

Thanks all!
Jeff
 
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