1995-2007 Vortec intake manifolds

[Ziegelsteinfaust]

I was putting stuff away, and I found a 5.7 Vortec lower intake manifold. That I was messing with to make a 3 duece intake for my dad. So out of boredom I put it on my L99 4.3 V8 aka the mid 90's baby LT1 to see if it could work.

While it is a chonky girl. All it would take me to make it fit is some grinding to relocate the bolt holes. As it only uses the outer 8 bolts.

On the plus side. The runners are 7 inches long vs my LT's 2.5 inches. So I could get a big shot of torque that I am looking for.

Like I said the engine is a 1996 4.3 L99 V8 or baby LT1. It has a Corvette cam with bolt ons. On the very generous side 280 hp with 290lbft torque. Or we'll below what I understand the poppet valves to support of roughly 400/400.

How tuneable is the poppet valve system vs regular injectors?

Do you think the base manifold design is better then the 80's tpi set up?

[AussieinNC]

TBI is essentially a replacement carburetor with some metering capabilities.

EFI is infinitely more tunable than TBI as each injector could be tuned to perfection if each cylinder had a wideband O2 sensor.

Even more tunability is achievable by utilizing direct combustion chamber style injection as most modern engines have progressed to.

Adding direct fire coil on plug ignition systems also aids the tuneability and reliability.

As far as runner length is concerned, longer runners produce more torque and as we all know, it takes torque to get the work done.

When the modern engines move to hydrogen for fuel a lot of the current emission equipment will become redundant.

Here is some drool samples for you that already exist...

https://www.jegs.com/i/FITech+Fuel+I...UaAtdREALw_wcB

[truckster]

I can only disagree with one thing Aussie said - I don't think hydrogen is the future. 95% of hydrogen comes from fossil fuels, and that's not likely to change in the foreseeable future.

[AussieinNC]

Yes, current hydrogen production has a carbon origin...

Toyota are working on a process to split the H2 out of plain old water, with the net result of an increase in O2 and zero emissions.

The future is just around the corner...and its not EV's/

EV's are not sustainable...and our infrastructure cant support our power needs now without 40% of the national fleet being EV...

[truckster]

I agree EVs are not the answer, but electrolysis requires a huge amount of electricity, and if you use seawater it also leave behind some pretty nasty residue. The problem with hydrogen is that, even though it's the most abundant element in the universe, it's very rare on Earth except for in combination of other elements. It takes a lot of energy to break those bonds.

I personally think that we will need a new technology we have yet to discover if we're ever going escape the use of fossil fuels.

[Ziegelsteinfaust]

Originally Posted by AussieinNC

TBI is essentially a replacement carburetor with some metering capabilities.

EFI is infinitely more tunable than TBI as each injector could be tuned to perfection if each cylinder had a wideband O2 sensor.

Even more tunability is achievable by utilizing direct combustion chamber style injection as most modern engines have progressed to.

Adding direct fire coil on plug ignition systems also aids the tuneability and reliability.

As far as runner length is concerned, longer runners produce more torque and as we all know, it takes torque to get the work done.

When the modern engines move to hydrogen for fuel a lot of the current emission equipment will become redundant.

Here is some drool samples for you that already exist...

https://www.jegs.com/i/FITech+Fuel+I...UaAtdREALw_wcB

Tbi is not the vortec with poppet injectors. The poppet wre 7sed 95 to 14 roughly

[truckster]

The poppet valves can't be tuned. I understand later model L31 Vortecs used an updated spider that had true multipoint injectors. I don't know if they're still available.

[Tom]

Originally Posted by truckster

The poppet valves can't be tuned. I understand later model L31 Vortecs used an updated spider that had true multipoint injectors. I don't know if they're still available.

96-2000 was vortec with poppet injectors. They all came poppet from the factory. Chevy release an updated MPI setup that turns the poppets into 8 mini injectors. They can be retrofitted to any vortec small block.

None can be tuned for more flow. That requires a marine intake manifold that uses normal injectors.

[57taskforce]

Napa and others carry the aftermarket version of multi point injectors too. I’ve used them with pretty good success in the past. The original style are junk just like the CPI 4.3 spider that was in the 92-95 S10 blazers.