[WILWAXU]

Originally Posted by wnta1ss

... The original Z28 was a homologation special for the SCCA Trans American championship which capped the displacement at 5 liters...

I think that is exactly why you might see one again. The IMSA Corvettes have been running a 5.5 liter engine for a number of years with severe intake restrictions. Also, Cadillac is pulling out of Pirelli World Challenge, might be a spot for a 5 liter Camaro there

I imagine a Camaro GT4 with a 5 liter... and maybe a VIN

[TLSTWIN]

Originally Posted by WILWAXU

You probably saw the Hot Wheels COPO, it has a supercharged LSX.

It was orange, that could've been it

[GrimReaperSS]

Originally Posted by kingbambino22

You’re welcome. Remember NHRA hp ratings is way different that SAE. That motor is at least 550 SAE hp or better to be an engine in a COPO Camaro. The LS7 is rated at 470 hp for the COPO. The 2016 COPO Camaro 6.2 engine was rated at NHRA 410 hp also.

Not judging, but how is NHRA HP different than SAE HP? Do you have a way of knowing how the NHRA certifies its HP ratings? I saw something on their page about Automatic Horsepower Factoring System, but it seemed a bit complex to me. Obviously the 427 makes 505 HP in street form, but only 470 in NHRA certification, so it is different in some way.

[chain777]

You guys do realize this motor is in a car that isn't street legal, right? It wouldn't make nearly as much power if it was re-engineered for street use to meet fuel economy and emissions regulations. Not to mention it's designed for a drag car, not a track car.

You need the big displacement for big horsepower with a push-rod motor for a street legal car. The days of small displacement, high performance, street legal overhead valve motors are gone. GM and FCA are the only manufacturers left that still make high performance OHV motors, and they're all 6 liters plus for a reason.

[doc7000]

Originally Posted by GrimReaperSS

Not judging, but how is NHRA HP different than SAE HP? Do you have a way of knowing how the NHRA certifies its HP ratings? I saw something on their page about Automatic Horsepower Factoring System, but it seemed a bit complex to me. Obviously the 427 makes 505 HP in street form, but only 470 in NHRA certification, so it is different in some way.

The HP ratings on the COPO Camaros are not correct, I can't remember where I found the video but for the LS7 COPO car I remember one team stating that its making about 740BHP out of the box and after they did their work to it they were pushing north of 820BHP.

found the link: http://www.superchevy.com/how-to/eng...ro-ls7-engine/

So this 302 which has a 410HP rating is actually going to have a power rating much higher then that. As the LS7s are being pushed to over 8,000rpms this 302 with a 3 inch stroke is going to be pushed to well over that rpm limit meaning its going to make a massive amount of power.

Remember torque times rpm divided by 5252 = horsepower, so with only 5.0L of displacement you make your power by revving higher. They are probably going to push it to 10,000rpms if not higher, if you assume 95ft-lbs/L then you would be looking at 475ft-lbs of torque. For a drag racing setup it is likely to be tuned for high rpm, if you assume 430ft-lbs at 9,000rpms then that is 736BHP.

I don't know if Ford runs a normally aspirated 5.0L motor in their Cobra Jet motor however if they do then in theory the LT based 302 has a major rpm advantage over it.

[bsimms89]

The 580hp for the S/C 350 and 470 for the 427ci are NHRA rated horsepower, not the power that the engine actually produces.
NHRA stock eliminator and super stock racing is based on a class system that is based on the horsepower to weight ratio of the car, so if you're racing in stock eliminator there are many classes such as A, B, C and so on. Back in the old days you could have a car such as a '66 Nova which could come with a range of motor sizes and even different power rated engines of the same displacement such as a 327 rated from the factory at 275hp or 350hp. These cars would be in different classes even though they have the same size motor. Stock and superstock are a handicap based racing system, where one car gets a head start based on it's estimated dial time and they're set up such that if each car runs exactly their dial time they would finish at the same time. The only time it is a heads up race is if two cars that are in the same class happen to come up against each other because they have similar horsepower to weight ratios.

This being said a '66 Nova such as the one my dad used to race with a 327ci motor rated for 350hp made much more that 350hp. 350 was just the horsepower the engine was rated with from the factory, once you modified it (withing the strict rules governing stock and superstock) it could make over 600hp or 700hp if actually placed on the dyno, and run deep into the 10s.

Now for theses new copos, cobrajets and drag pacs since they are not street produced motors the manufacturers and the NHRA had to come up with a number to apply for the sake of having a class to put these cars in. Somehow chevy and the NHRA came up with rating the S/C 350 at 580hp, and the 427 at 470hp, when realistically as delivered the 350 makes around 1100hp and the 427 makes approximately 900hp. And once you start making modifications to them like changing the pulley on the supercharger from the 3.5" pulley it comes with to the 3.25" pulley allowed by the nhra, blueprinting the motor, and adjusting the tune you can make around 1200hp.

The blueprints for every stock or superstock engine combination allowed can be found here:http://www.nhraracer.com/content/gen...634&zoneid=132
Short answer: no they don't make 580hp and 470hp, these are just arbitrary numbers so the car can be placed in a class. Even as delivered they still make around 1100hp and 900hp.

What exactly the 302 will be making remains to be seen

[Bhobbs]

What the COPO engines make is irrelevant to a street car. The 302 is street legal form would not cut it for the Z/28.

[kingbambino22]

Originally Posted by Bhobbs

What the COPO engines make is irrelevant to a street car. The 302 is street legal form would not cut it for the Z/28.

It cut it before. If GM wants it to "cut it" they can make it "cut it."

[Bhobbs]

Originally Posted by kingbambino22

It cut it before. If GM wants it to "cut it" they can make it "cut it."

Do you mean the DZ302? Almost 50 years ago?

Look at the effort Ford made to get the power they needed out of a 5.2 liter engine. A 5.0 LTx won’t make nearly as much power. There’s no reason to stick to 5.0 liters, when the block can support at least 7.0 liters. Ford was capped at 5.2 liters by their block. GM isn’t.