First LS1 Engine Tips
Thread Starter
Teching In
Joined: Oct 2021
Posts: 5
Likes: 1
From: Alberta, Canada
First LS1 Engine Tips I'm currently running a small block 350 with vortec swapped heads in my 1985 GMC K10, and a buddy at work is selling me his 2004 6L (I'm assuming LQ4 based on research, I haven't asked) I'm very green with engines, but I've been learning a lot the past year.
The first thing I'm looking at doing is putting a Summit Racing 8719R1 cam in it with the Summit 174002 springs, replacing valve stems as well. He mentioned he's got some 243 heads for sale which would bring it up to around 10.5:1 to 11:1 CR which would basically require 91/93 octane fuel. I'm pretty sure the LQ4 came with 317 heads giving it a 9.4:1 CR.
Just trying to figure out what others have done with theirs, I'm not looking at purely maximizing fuel economy but it's a nice bonus, I was looking at pure torque cams, but for the effort and minimal savings, it looks like the 8719 would be a good all around option, maybe the 243 heads wouldn't be so bad with different timing running on 87 octane?
I'm probably sitting on 170HP as it stands with my SBC, so definitely looking forward to grabbing this engine and getting it installed! Trucks sitting on 4" lift with 35s, SM465 4 speed with 4.10 gears, definitely need beefier axles than the GM 10 bolt / D44 I've got now.
Is there anything else recommended to change out other than cam, springs and associated gaskets? Is it worth getting the 243 heads for it? It's got 180,000km (110,000 miles).
The first thing I'm looking at doing is putting a Summit Racing 8719R1 cam in it with the Summit 174002 springs, replacing valve stems as well. He mentioned he's got some 243 heads for sale which would bring it up to around 10.5:1 to 11:1 CR which would basically require 91/93 octane fuel. I'm pretty sure the LQ4 came with 317 heads giving it a 9.4:1 CR.
Just trying to figure out what others have done with theirs, I'm not looking at purely maximizing fuel economy but it's a nice bonus, I was looking at pure torque cams, but for the effort and minimal savings, it looks like the 8719 would be a good all around option, maybe the 243 heads wouldn't be so bad with different timing running on 87 octane?
I'm probably sitting on 170HP as it stands with my SBC, so definitely looking forward to grabbing this engine and getting it installed! Trucks sitting on 4" lift with 35s, SM465 4 speed with 4.10 gears, definitely need beefier axles than the GM 10 bolt / D44 I've got now.
Is there anything else recommended to change out other than cam, springs and associated gaskets? Is it worth getting the 243 heads for it? It's got 180,000km (110,000 miles).
I'm currently running a small block 350 with vortec swapped heads in my 1985 GMC K10, and a buddy at work is selling me his 2004 6L (I'm assuming LQ4 based on research, I haven't asked) I'm very green with engines, but I've been learning a lot the past year.
I'm probably sitting on 170HP as it stands with my SBC, so definitely looking forward to grabbing this engine and getting it installed! Trucks sitting on 4" lift with 35s, SM465 4 speed with 4.10 gears, definitely need beefier axles than the GM 10 bolt / D44 I've got now.
I'm probably sitting on 170HP as it stands with my SBC, so definitely looking forward to grabbing this engine and getting it installed! Trucks sitting on 4" lift with 35s, SM465 4 speed with 4.10 gears, definitely need beefier axles than the GM 10 bolt / D44 I've got now.
Depending on which year LQ4 it's probably 300 to 330 hp. The cam and heads are nice additions if $$$ is available and everything else is covered.
Best wishes with the project.
Thread Starter
Teching In
Joined: Oct 2021
Posts: 5
Likes: 1
From: Alberta, Canada
Does the LQ4 come with the PCM and wiring harness? The fuel system may need a higher pressure fuel pump. Is your current SBC Vortec 350 a TBI? If so it will need a different fuel pump good for ~60 psi for port fuel injection. Some sort of tuning software be needed as well.
Depending on which year LQ4 it's probably 300 to 330 hp. The cam and heads are nice additions if $$$ is available and everything else is covered.
Best wishes with the project.
Depending on which year LQ4 it's probably 300 to 330 hp. The cam and heads are nice additions if $$$ is available and everything else is covered.
Best wishes with the project.
Edit: he was originally selling the engine for $1000 Canadian, but he's going with a different setup so he's including the harness, VATs deleted for $1500, then the headers he added $250, and he's letting the heads go for $500, so I was thinking about using that $500 to swap camshaft instead, but if the heads are a big improvement I was going to go all in
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Joined: Jan 2008
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From: Ohio, Georgia, Nevada, Texas
OP,
The 8719R1 would be a nice match for what you're looking to do with this combo. The 243 heads would be a nice added benefit if the budget permits. As far as compression you're right, a stock LQ4 is 9.4:1 with 317 heads. Going to the 243's you'd be right around 10:1. Go with some .040" Cometic head gaskets and bump that up to around 10.3:1. Boosting compression improves power and torque throughout the range. Going with .040" gaskets will also reduce quench. You should be right around .038" quench distance which is within the optimal range of .035-.045". Reducing quench helps create a more efficient combustion cycle and reduces the chance of knock.
As far as octane. At the 10:1-10.3:1 range, you can likely get away with 87. If you plan on towing much or hauling heavy loads you might find that 93 will be needed. You can always pull timing but it's not a good idea to constantly pull timing if static compression is too high.
We know our customers like combos so we put together cam swap combos. Check out the 8719R1 cam, spring, and gasket kit combo here.
Let us know if we can be of any further assistance. We'll be happy to help!
The 8719R1 would be a nice match for what you're looking to do with this combo. The 243 heads would be a nice added benefit if the budget permits. As far as compression you're right, a stock LQ4 is 9.4:1 with 317 heads. Going to the 243's you'd be right around 10:1. Go with some .040" Cometic head gaskets and bump that up to around 10.3:1. Boosting compression improves power and torque throughout the range. Going with .040" gaskets will also reduce quench. You should be right around .038" quench distance which is within the optimal range of .035-.045". Reducing quench helps create a more efficient combustion cycle and reduces the chance of knock.
As far as octane. At the 10:1-10.3:1 range, you can likely get away with 87. If you plan on towing much or hauling heavy loads you might find that 93 will be needed. You can always pull timing but it's not a good idea to constantly pull timing if static compression is too high.
We know our customers like combos so we put together cam swap combos. Check out the 8719R1 cam, spring, and gasket kit combo here.
Let us know if we can be of any further assistance. We'll be happy to help!
