Tootie Pang

iTrader: (2)

I am just really enjoying mostly my stock L98 (warm cam) and T5 setup in my convertible and am already starting to feel the pangs of a new project. I've always loved the sound of a high revving small block.

So I'm thinking how to do this. I can go one of two ways - swap or sbc. I'm sure it will come to money vs practicality.

I'm really liking the vert so I may use that car as the platform. Some constraints:

• It needs to be able to drive as calmly as grocery-getter, doesn't overheat in warm weather, idles smoothly, creature comforts like AC, and can be reasonably serviced (i.e. no routine maintenance jobs that require motor pulling)
• Revs to and makes power through 7,500 RPM minimum and minimum 500hp, normally aspirated
• Manual trans or DCT
• Money below $10K+-ish

I realize this is fairly ambitious but I think it would also be very cool. Really nothing like the sound of a singing V8 small block. Let's keep the discussion to high level combos. No need for nitty gritty at this point. Mainly just a feasibility and what combos/setups.

GeneralDisorder

iTrader: (1)

Then you need an LS7

$10k most likely isn't going to get you there though. Maybe - check prices on used engines.

*edit* - might be feasible on about that budget - https://www.ebay.com/i/303506623856

GD

five7kid

iTrader: (14)

"Idles smoothly" and "revs to 7500" are mutually exclusive (unless you have variable valve timing).

GTA matt

iTrader: (1)

Lower your rpm to 6500 and you'll be more likely to achieve your goals. A camshaft that will pull to 7500 won't idle smoothly, and will be pretty rowdy below 2000. There will be a lot of valvetrain maintenance, as well as a pretty good part of the budget going towards high quality valvetrain components. You'll need a very good cylinder head too. Bottom end doesn't need to be anything exotic, but high quality to maintain reliability. I would expect power for a good 7500 rpm 400+ cubic inch engine to be north of 650. A smaller engine will be even more rowdy at lower rpm's. A 6500 engine will be much more budget and maintenance friendly, easily achieve over 500 hp and be more driveable as a street car.

Tootie Pang

iTrader: (2)

Yeah, I think variable valve timing is the only way to get there.

LS7 huh? I did say $10K-ISH, which means I would expect the planned budget to grow to $15K of course ;-). Lol.

ironwill

You're describing a built LS here (the $10K limit is out the window).




A gen-1 small block that has been built to make reliable power to 7500 is going to have a ragged 1500 rpm idle and won't make any usable power below maybe 3000-3500 rpm. It will be a good trick to make it run on pump gas and also to not overheat in traffic, especially with A/C.

If I had plenty of $$$, and were to attempt such a build, I'd look at a Dart 400 block with a custom 3.48-stroke crank. Lots of compression, the largest valves that could be stuffed into aluminum heads, and roller-everything. I'd have to feed it with an aftermarket FI setup that's tunable on the fly; carburetors on such engines are just really finicky, especially where idle quality is an issue.

GeneralDisorder

iTrader: (1)

LS7 is 505 HP from the factory and has a 7k redline. Change out the camshaft and the valve springs and you'll likely get close to your goal. Though you will need a different drivetrain to hold that power. I did a Magnuson supercharger on an '09 Vette and we made 850 at the wheels.

The LS7 is a stock unit from a Vette and makes exactly your HP goal. Easier and cheaper than a custom build. But again you will need to up your budget for drivetrain and LS swap components. $15k might come close for a DIY build. Would probably be half what you need to pay a performance shop to do it.

GD

Tootie Pang

iTrader: (2)

Good stuff. Yeah, I think the gen1 sbc isn't going to behave in daily driver mode. The wonders of modern technology are too real. I will research my LS's. Lots of good info I found on Wikipedia.

rgauder

iTrader: (1)

Don't short change the sbc for that power level. You may have to lower your peak rpm level though.

ShiftyCapone

iTrader: (7)

+1 on the LS7. Building an LS to do that will be more than $10k. Likely double or more. My 377 LS is built to do what you are looking at it and you better double your budget to start. $10k will barely cover the intake, heads, oiling system and valvetrain. Going with an LS7 will get you there faster and cheaper. Then you just need another $20k for the rest of the swap.