Converting a Chevy LY6 into a LS3

[Snagglefoot]

I have a 6.0 Chevy LY6 in my Burb. Here is an interesting article praising the LY6 (which I liked) and discussed how to turn it into a high performance engine. All you Chevy fans enjoy.

https://www.motortrend.com/how-to/converting-truck-ly6-engine-ls3-power/

 

[Snagglefoot]

Here”s a shot of the square port intake ports of the LY6 heads that flow more than the cathedral port LQ4 heads.

 

[clinebarger]

They sure used a click bait title, The LS3 has quite a bit more static compression than a LY6.....With it's flat top pistons & .070 overbore.

The L92 in my Camaro has all the LS3 hardware including hollow Intake Valves, But I reused the L92 pistons that have VVT valve reliefs which lowers the SC from 10.8:1 to 10.3:1. IIRC....The LY6 has a 9.6:1.

 

[clinebarger]

I much prefer Cathedral style heads on a truck engine.....It's not about peak flow numbers. A set of mildly ported "317" LQ4/LQ9 cylinder heads with the right Quench will outperform a "823" rectangle port head in under the curve power/torque production every time.

 

[Snagglefoot]

Sure enough, but the article was really more about making peak power from a junkyard truck engine. Drivability was not part of the deal, and I doubt the intent was to put it back into a truck. It made 475 HP at 5800 rpm with no need to go out and buy cathedral heads and port them.

 

[Jake_J]

The truck intakes actually flow better then the LS3 intake so it's more of a cosmetic or height reduction upgrade. Also the dyno numbers are 60's style fantasy numbers as they run the engines without an air intake, air filter, alternator, water pump, power steering pump, muffler, resonator, etc so even a stock engine will blow past the SAE numbers easily.

 

[clinebarger]

The truck intakes actually flow better then the LS3 intake so it's more of a cosmetic or height reduction upgrade. Also the dyno numbers are 60's style fantasy numbers as they run the engines without an air intake, air filter, alternator, water pump, power steering pump, muffler, resonator, etc so even a stock engine will blow past the SAE numbers easily.

The LS3 intake was designed for the C6 Corvette which has one of the lowest hood lines ever for a front engine vehicle.

My Camaro didn't exactly light up it up on a Mustang Chassis Dyno at 406rwhp & 444rwtq....But every bit as quick as owners that claim 500rwhp.

 

[GMBoy]

I much prefer Cathedral style heads on a truck engine.....It's not about peak flow numbers. A set of mildly ported "317" LQ4/LQ9 cylinder heads with the right Quench will outperform a "823" rectangle port head in under the curve power/torque production every time.

That's good information there. I've been thinking of doing a mild port on my 06 Sierra Denali LQ9.

 

[RooflessVW]

The LY6 has a 9.6:1.