ewingr

I've been reading through the thread, and don't find one that may answer this. Just curious.

I'm putting a 0 mile '04 350hp Corvette motor in my '56 Chevy Convertible. Using an A4. Only 'mods' will be headers form S&P that allow clearing the 605 steering, and most likely, I'll eliminate the MAF and use speed density. (Actually I don't have a MAF, so saving the cost...that's the reason for eliminating it)

I've heard that the 350 quoted HP is a bit low.

Any idea what range it would probably be at?

99C5JA

The LS1 (which is 346ci btw) in the Corvette only differed from the LS1 in the F-bodies in that it had a slightly bigger cam. The LS1 was generally underrated and F-bodies with solid axles are the closest comparison to what your setup will likely be. A stock A4 F-body makes about 300rwhp bone stock. Add on headers and low restriction filter and you are looking at probably 330-340rwhp. So if you figure 20% driveline loss you are looking at 410-425 crank hp. Those figures may be a bit off, but I'd say that 400hp is probably a safe number.

vettenuts

iTrader: (4)

Actually, the f-body and the y-body had the same cam. The f-body hp loss was mostly on the intake side and some on the exhaust.

If you read any of the magazines, it appears the crate motors are putting down more than the advertised 350 crankshaft hp.

ewingr

Interesting. Why do you think that is?

vettenuts

iTrader: (4)

I'm not sure, but several articles have shown higher numbers in stock form.

300bhp/ton

Remember to take any of these numbers with a pinch of salt.

GM rate their engine in SAE Net this standard is very strict and requires a specific type of engine dyno.

Engine Masters tested a LS6 crate engine to see if it exceeded the rated numbers. And they admitted that even after SAE Net correction that on their dyno the engine would need to make ~415bhp to be comparable to the 405bhp quoted by GM. This was due to the dyno type. I think in the end it ended up with the LS6 making an equiverlent to 407 or 409bhp SAE Net.

So circa 350bhp is probably about right for a 2004 crate LS1. Although it would only take a few mods and 450-500bhp SAE Net would be pretty easy from it.

99C5JA

They used different part #'s until 01 and I could swear I've read that the Vette cam was slightly larger until that point (though I didn't remember they were the same after '01). As for dyno #'s the F-body generally dyno'd higher due to the driveline loss of the Vette's IRS. Since this is an '04 they would be the same cam, and the F-body's solid rear would make for the closest comparison. As for the SAE net values vs. what we see thrown around here, I'm not really sure how to normalize the figures. But even if we assume that it will be close to the rated power, the headers will still give it a hefty boost.