LT4 exhaust Valves
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Burning Brakes
Joined: Mar 2018
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LT4 exhaust Valves
The Lt4 exhaust valves seem to be nothing special. Stainless.
There are inconel and "Super allow" valves on the market in the same exact sizes.
One such "Inconel" exhaust valve is actually in the truck L8T engine. Same size as for the other Gen V engines (at least the Lt1 and Lt4).
Can't get them even though they are on all those trucks. Nice upgrade for the Lt4 exhaust. Backordered indefinitely like a few other items on the C7.
And they are half the cost of these:
https://www.jegs.com/i/Manley/660/12349-1/10002/-1
Also Ferrea, who I like as a company makes these: F2410P
https://gwatneyperformance.com/produ...valves-f2410p/
Actually Katech sells them as a performance option for the Gen V: https://katechengines.com/i-30497954...ust-valve.html
I bought the Ferrea as I wanted to know more about it. It is ~9x grams compared to ~7x grams on the stock LT4 exhaust. That is a pretty big difference. Tool steel retainers will be reducing the total mass in the valve train a bit, but those heavy exhaust valves... kinda concerning.
I would love to get one of the (cheaper) Inconel valves from the L8T on a scale to see if they are a compromise on weight. I may also buy one of the manley valves to see as the material manley uses is supposed to be different from the dense superalloy of the Ferreas.
There are inconel and "Super allow" valves on the market in the same exact sizes.
One such "Inconel" exhaust valve is actually in the truck L8T engine. Same size as for the other Gen V engines (at least the Lt1 and Lt4).
Can't get them even though they are on all those trucks. Nice upgrade for the Lt4 exhaust. Backordered indefinitely like a few other items on the C7.
And they are half the cost of these:
https://www.jegs.com/i/Manley/660/12349-1/10002/-1
Also Ferrea, who I like as a company makes these: F2410P
https://gwatneyperformance.com/produ...valves-f2410p/
Actually Katech sells them as a performance option for the Gen V: https://katechengines.com/i-30497954...ust-valve.html
I bought the Ferrea as I wanted to know more about it. It is ~9x grams compared to ~7x grams on the stock LT4 exhaust. That is a pretty big difference. Tool steel retainers will be reducing the total mass in the valve train a bit, but those heavy exhaust valves... kinda concerning.
I would love to get one of the (cheaper) Inconel valves from the L8T on a scale to see if they are a compromise on weight. I may also buy one of the manley valves to see as the material manley uses is supposed to be different from the dense superalloy of the Ferreas.
Last edited by bc928; Feb 23, 2024 at 01:23 AM.
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Joined: Dec 2008
Posts: 137
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The Lt4 exhaust valves seem to be nothing special. Stainless.
There are inconel and "Super allow" valves on the market in the same exact sizes.
One such "Inconel" exhaust valve is actually in the truck L8T engine. Same size as for the other Gen V engines (at least the Lt1 and Lt4).
Can't get them even though they are on all those trucks. Nice upgrade for the Lt4 exhaust. Backordered indefinitely like a few other items on the C7.
And they are half the cost of these:
https://www.jegs.com/i/Manley/660/12349-1/10002/-1
Also Ferrea, who I like as a company makes these: F2410P
https://gwatneyperformance.com/produ...valves-f2410p/
Actually Katech sells them as a performance option for the Gen V: https://katechengines.com/i-30497954...ust-valve.html
I bought the Ferrea as I wanted to know more about it. It is ~9x grams compared to ~7x grams on the stock LT4 exhaust. That is a pretty big difference. Tool steel retainers will be reducing the total mass in the valve train a bit, but those heavy exhaust valves... kinda concerning.
I would love to get one of the (cheaper) Inconel valves from the L8T on a scale to see if they are a compromise on weight. I may also buy one of the manley valves to see as the material manley uses is supposed to be different from the dense superalloy of the Ferreas.
There are inconel and "Super allow" valves on the market in the same exact sizes.
One such "Inconel" exhaust valve is actually in the truck L8T engine. Same size as for the other Gen V engines (at least the Lt1 and Lt4).
Can't get them even though they are on all those trucks. Nice upgrade for the Lt4 exhaust. Backordered indefinitely like a few other items on the C7.
And they are half the cost of these:
https://www.jegs.com/i/Manley/660/12349-1/10002/-1
Also Ferrea, who I like as a company makes these: F2410P
https://gwatneyperformance.com/produ...valves-f2410p/
Actually Katech sells them as a performance option for the Gen V: https://katechengines.com/i-30497954...ust-valve.html
I bought the Ferrea as I wanted to know more about it. It is ~9x grams compared to ~7x grams on the stock LT4 exhaust. That is a pretty big difference. Tool steel retainers will be reducing the total mass in the valve train a bit, but those heavy exhaust valves... kinda concerning.
I would love to get one of the (cheaper) Inconel valves from the L8T on a scale to see if they are a compromise on weight. I may also buy one of the manley valves to see as the material manley uses is supposed to be different from the dense superalloy of the Ferreas.
Burning Brakes
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From: Louisiana
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Lost, since you can throw more pressure at the Lt-4 or even ls9 to make more power than the 427, since the 427 has the cylinders too thin between each other, to throw real pressure at them. Also, with lsx blocks/heads with extra head bolts, holds even more pressure instead.
LS7 block and you can see how thin the cylinder sleeves are between each other, and why you can't throw major power at it.
As for DI, verse intake port injection, would favor intake injecting any day of the week if your going to run any PCV system on the engine, that is going to be dumping oil back into the intake manifold. With port injection, fuel down the intake manifolds does keep the intake valves clean, over the DI problem of no fuel down the runners to clean off the oil that the PCV is pushing down the same intakes.
Also at add, varable cams is only for Na motors to help them breath better, and goes out when the window when the motor is being forced feed breath'd by the blower instead.
So with 2650, you have the boost to make 1KHP, and now just need to build the motor that can hold that much pressure to make that kind of power.
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Burning Brakes
Joined: Mar 2018
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Thread Starter
Burning Brakes
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Lost, since you can throw more pressure at the Lt-4 or even ls9 to make more power than the 427, since the 427 has the cylinders too thin between each other, to throw real pressure at them. Also, with lsx blocks/heads with extra head bolts, holds even more pressure instead.
LS7 block and you can see how thin the cylinder sleeves are between each other, and why you can't throw major power at it.
As for DI, verse intake port injection, would favor intake injecting any day of the week if your going to run any PCV system on the engine, that is going to be dumping oil back into the intake manifold. With port injection, fuel down the intake manifolds does keep the intake valves clean, over the DI problem of no fuel down the runners to clean off the oil that the PCV is pushing down the same intakes.
Also at add, varable cams is only for Na motors to help them breath better, and goes out when the window when the motor is being forced feed breath'd by the blower instead.
So with 2650, you have the boost to make 1KHP, and now just need to build the motor that can hold that much pressure to make that kind of power.
LS7 block and you can see how thin the cylinder sleeves are between each other, and why you can't throw major power at it.
As for DI, verse intake port injection, would favor intake injecting any day of the week if your going to run any PCV system on the engine, that is going to be dumping oil back into the intake manifold. With port injection, fuel down the intake manifolds does keep the intake valves clean, over the DI problem of no fuel down the runners to clean off the oil that the PCV is pushing down the same intakes.
Also at add, varable cams is only for Na motors to help them breath better, and goes out when the window when the motor is being forced feed breath'd by the blower instead.
So with 2650, you have the boost to make 1KHP, and now just need to build the motor that can hold that much pressure to make that kind of power.
Yes, you are lost. Or your over ten year old account was taken over by a random bot. This thread is about valves. Why the cookie cutter post?
Last edited by bc928; Feb 23, 2024 at 05:50 PM.
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Burning Brakes
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Has to do with valve float on the super charged motor, and why the LT4 exhaust valves are lighter than the LT1's
https://www.onallcylinders.com/2019/...do-you-fix-it/
Also to point out, the way that GM tunes the motors, on the NA motors, they will go flat before redline in HP, while on the motors that are supercharged being forced feed, do not and you bang off the rev limiter still climbing hard in HP instead.
https://www.onallcylinders.com/2019/...do-you-fix-it/
Also to point out, the way that GM tunes the motors, on the NA motors, they will go flat before redline in HP, while on the motors that are supercharged being forced feed, do not and you bang off the rev limiter still climbing hard in HP instead.
Thread Starter
Burning Brakes
Joined: Mar 2018
Posts: 849
Likes: 112
Wrong. LT1 and LT4 exhaust valves are same part number.
Has to do with valve float on the super charged motor, and why the LT4 exhaust valves are lighter than the LT1's
https://www.onallcylinders.com/2019/...do-you-fix-it/
Also to point out, the way that GM tunes the motors, on the NA motors, they will go flat before redline in HP, while on the motors that are supercharged being forced feed, do not and you bang off the rev limiter still climbing hard in HP instead.
https://www.onallcylinders.com/2019/...do-you-fix-it/
Also to point out, the way that GM tunes the motors, on the NA motors, they will go flat before redline in HP, while on the motors that are supercharged being forced feed, do not and you bang off the rev limiter still climbing hard in HP instead.
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Thread Starter
Burning Brakes
Joined: Mar 2018
Posts: 849
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Burning Brakes
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I wanted to update here. The inconel part number for the L8T that has been floating around and I posted here seems to have been swapped in a cost saving or possible convergence with -
"Yes, The 12671857 was removed and replaced by the 12733470"
"Yes, The 12671857 was removed and replaced by the 12733470"
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Burning Brakes
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OEM LT1/LT4 - 74g
OEM L8T Inconel - 96g
Ferrea Super Alloy - 95g