Help choosing a 4th gen Chevy v8

[dap03]

So I was looking at all the different 4th gen engines chevy has was curious as to what engine to start with. I would be looking at an engine where it stays as close to stock as possible.

 I noticed that the L20 has an 8.8 compression ratio according to Wikipedia. The Ly2 is at 9.08. Would these be reasonable CR's to start with? Or could I go with something like an Lmg at 9.6 or an Lc9 at 9.95.

Would it be necessary to pick an engine that previously came e85 compatible or is it nearly the same to start with a regular one?

I don't really care for the 6.0 tax so a 4.8 or 5.3 would suit finely.

 Is there a specific engine that people look at to boost over other ones?

Sorry for all the questions.

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[digitalsolo]

It's not the 90s anymore, get as much compression ratio as you can, upwards of 10.x:1 with boost and you'll be fine.      E85 or not doesn't much matter as you'll be replacing 99% of that, though having a flex ECU might help if you're keeping the stock ECU.

[dap03]

Thank you. I didn't realize the engines were this strong.

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[Exidous]

10:1 on decent boost is more like direct injection numbers but if you run E85 you can run 10:1 on just about any motor. Flex fuel and an aftermarket ECU is the way to go but stock ECU's can make it work.

A gen 4 5.3L is a REALLY good way to go. Aluminum if you can afford the little extra otherwise the iron will do just fine. Rotating assembly, heads and intake are all about the same anyway for the gen 4 motors.

Most folks can run 800whp through a nearly stock gen 4 5.3L. Cam and associated mods and that's it. Maybe a non-truck intake for the lower height and f-body or corvette accessories.

[shainiac]

I always recommend the LC9 engines. They use a beefy Siamese-bore aluminum block with thick sleeves. They also come with the best small-bore heads (799/243 stamped) and have stronger rods/pistons than the earlier 5.3 blocks.
Using an aluminum block also saves you about 100# off the front of the car.
Another benefit of the LC9 is that they're usually Displacement on Demand engines. This isn't something that you'd likely use, but I mention this because those DoD systems are prone to lifter failure.
If you're going to replace the cam, valve springs, and lifters (cheap and easy power), you'll replace all the problem parts that put these motors in the junkyard to begin with. I picked up my LC9 for $500 because it had 2 collapsed lifters and ran horribly, even though it only had 70k miles and looked brand new inside.

Like others have mentioned, 10:1 CR is no big deal. I run flex fuel, but 90% of the time, the car is on 93oct. I run 12-13psi on 93 (~620whp) and 18-19psi on pump E85 (~720whp).
I have very small turbos, so my setup tapped out around 18psi, but a good friend of mine ran 8.0 @ 165mph with a bone-stock LC9 with a cam, valve springs, and a honkin turboat over 30psi.
The LC9s are great bang for the buck.

[dap03]

Is vvt an issue or is it easily removed?

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[shainiac]

You'll need a new timing cover and cam sprocket. Most aftermarket cams require you to switch to a 3-bolt sprocket anyways. You may actually be able to reuse timing cover, but the VVT is pretty ugly.
To delete DoD, I bought a Gen4 4.8 non-DoD valley cover. It was less than $50 for a GM part that has o-rings to seal the DoD oil passages.

[gnx7]

'04.5 and newer engine has the better rods.... LS9 gaskets and ARP head studs with DOD delete stuff.  The LS7 lifters are hard to find right now.  I would try to find a 5.3 doesn't matter steel block or alum.... Alum preferred to save 80lbs.

If you need anything from BTR I'm a dealer as well as VS Racing (turbos).... they have a Next Gen 78/76 T4 that can make 1000rwhp for under $800.  An S480 is a T6 and huge and will make similar power for a couple hundred more and made by Borg Warner and much heavier.

norcalmotorsport@gmail.com

[forcefed86]

'04.5 and newer engine has the better rods.... LS9 gaskets and ARP head studs with DOD delete stuff.  The LS7 lifters are hard to find right now.  I would try to find a 5.3 doesn't matter steel block or alum.... Alum preferred to save 80lbs.

If you need anything from BTR I'm a dealer as well as VS Racing (turbos).... they have a Next Gen 78/76 T4 that can make 1000rwhp for under $800.  An S480 is a T6 and huge and will make similar power for a couple hundred more and made by Borg Warner and much heavier.

norcalmotorsport@gmail.com

Looks like the VSR gen 1 T6 billet S480 is $695. (Also what I happen to be running) Is there really any back to back testing on the next GEN 78/75 T4 VS a Gen1 t6 S480?

 I find it hard to believe they are keeping up being a smaller frame unit and a T4. Just curious to see some actual tests. Best I've seen 78/75 nex gen do 156ish with one on 26lbs and a 4.8. Was def out of steam. I've seen 169 out of a T6 LS3 VSR s480. 

 

[gnx7]

There is now a Gen3 Next Gen 78/75 that makes about another 100rwhp over the Next Gen release as it is a slightly larger compressor wheel.  Supposedly same spool up time/RPM... just more power from better technology.  I bought one for a customer and it weighs 29lbs and is in a small T4 frame.  Has a 4" Vband exit on the turbine housing for the downpipe and divided T4 housing.  Compressor wheel is billet and housing has a provision for a compressor speed sensor to add on.   The T6 is a huge and heavy beast....