I've been trying to say, this should be an LS style big bore V6. So much potential...constantly trying to get the engine masters guy's to do something turbo
One thing to think about with flow is that each cylinder is like a lt1 cylinder. It’s 3/4 of a 350. So you can’t think oh it’s a 4.3 I need less flow. It’s a 350 cylinder. It needs a 350 head. And exhaust headers and intake manifold sized as if it’s a 350 as well. When it lost 2 cylinders it also lost 4 valves and 2 sets of intake and exhaust ports.
The low lift is great so the valve seats and chambers must be good. The fact that it chokes is probably the pinch area needs opening a little. Wouldn't take much to get these near 300.
What aftermarket Engine Management for these VVT, direct injection, engines do you recommend for an outside of stock swap? Im going to use a 4L80E with it
We don't have any LS3 flow data at the moment but we'll lean on this test by Richard Holdener on an unported LS3. Shows over 300cfm on the intake from 0.600 on up through 0.700 and over 200cfm on the exhaust from 0.500 through 0.700. www.motortrend.com/how-to/hrdp-1102-ls3-l92-rectangle-port-cylinder-heads-test/
You're asking the wrong question. The LV3 flows more than enough for the 4.3 up to 6500 rpm. More flow will not translate to more power. The best gen 3 heads are the 706, which flow less than the LS2 heads.
Not surprised. All of the Gen V factory heads give up at .500 intake lift. This one hit 238 cfm @ .500, then crept up to 250 @ .600, which wasn't too bad. Porting would help a lot.
GM spent 6 million computer hours, with expensive software, to optimize the combustion system around the V6. The V8s are modified V6s. Assume they know what they're doing. Stock heads will support 400+bhp NA, and several hundred with a turbo. GM designed the heads to do specific things, and imho most head porters ruin them. btw, it's not a "small" engine. it's 3/4 of a 350, and it has bigger cylinders than the 5.3.
I've been trying to say, this should be an LS style big bore V6. So much potential...constantly trying to get the engine masters guy's to do something turbo
See Richard holdener for the turbo.
One thing to think about with flow is that each cylinder is like a lt1 cylinder. It’s 3/4 of a 350. So you can’t think oh it’s a 4.3 I need less flow. It’s a 350 cylinder. It needs a 350 head. And exhaust headers and intake manifold sized as if it’s a 350 as well. When it lost 2 cylinders it also lost 4 valves and 2 sets of intake and exhaust ports.
I need that stage 3 cam for the LV3 Nick mentioned! I have an awesome build that needs all the chop I can get!
I think one of these V-6 with a couple of turbos would be a great transfer into say a small truck or old sports car like an old Porsche 914 or Fiero
Would love to swap one of these in my 2002 ZR2 pickup project.
The low lift is great so the valve seats and chambers must be good. The fact that it chokes is probably the pinch area needs opening a little. Wouldn't take much to get these near 300.
Been waiting to see cam swap Dino Numbers
Great Video! I've been looking into getting a 4.3 project! Any chance there is a stock 4 or 6 bolt main with these 4.3 Blocks?
These are a 6-bolt design with two cross bolts :)
ua-cam.com/video/qlI5ecMKe1c/v-deo.html
Very helpful info here.
What aftermarket Engine Management for these VVT, direct injection, engines do you recommend for an outside of stock swap? Im going to use a 4L80E with it
These should have been in the Colorado's from the start.
Hi Nick, how does this flow compare to an LS2 or LS3 for example?
We don't have any LS3 flow data at the moment but we'll lean on this test by Richard Holdener on an unported LS3.
Shows over 300cfm on the intake from 0.600 on up through 0.700 and over 200cfm on the exhaust from 0.500 through 0.700.
www.motortrend.com/how-to/hrdp-1102-ls3-l92-rectangle-port-cylinder-heads-test/
You're asking the wrong question. The LV3 flows more than enough for the 4.3 up to 6500 rpm. More flow will not translate to more power. The best gen 3 heads are the 706, which flow less than the LS2 heads.
LS3's typically are 315 max intake CFM. With CNC porting, that goes up to 350.
Not surprised. All of the Gen V factory heads give up at .500 intake lift. This one hit 238 cfm @ .500, then crept up to 250 @ .600, which wasn't too bad. Porting would help a lot.
Spend your money on cnc combustion chambers to drop that 11:1 cr. and unshroud the valves.
Lv3 needs a miata like bread needs honey.
Like white on rice.
GM spent 6 million computer hours, with expensive software, to optimize the combustion system around the V6. The V8s are modified V6s. Assume they know what they're doing. Stock heads will support 400+bhp NA, and several hundred with a turbo. GM designed the heads to do specific things, and imho most head porters ruin them. btw, it's not a "small" engine. it's 3/4 of a 350, and it has bigger cylinders than the 5.3.
Make the stage 3 cam😳😳
We're working overtime to get this engine on the dyno so we can make decisions on our next cam packages.
Nick couldyoutalkalittlefaster? :)