[KingLT1]

Originally Posted by Walt88

I've always wondered, at what point do you need to upgrade the valvespings to prevent valve float under boost? I know LS truck engines really need it at anything past 10 psi but how do the LT1 valvesprings stack up?

The valve springs on the LT1 are quite a bit better then what is used on gen 3/4 LS truck motors.

[Idaho2018GTPremium]

Originally Posted by Walt88

I've always wondered, at what point do you need to upgrade the valvespings to prevent valve float under boost? I know LS truck engines really need it at anything past 10 psi but how do the LT1 valvesprings stack up?

Per the Hotrod article detailed writeup on the LT4: https://www.hotrod.com/articles/the-...e-z06s-lt4-v8/

"The LT4 has the same 6,600-rpm fuel cut-off as the LT1, so the two engines use the same valvesprings. "

[pavetim]

Somebody help me out. I am putting a 2018 zl1 SC on my 2017 SS. I am planning on running e85 as i run it now. Would like 600rwhp but need help picking a SC pulley size, i am guessing about 7psi of boost?

[Joshinator99]

Originally Posted by pavetim

Somebody help me out. I am putting a 2018 zl1 SC on my 2017 SS. I am planning on running e85 as i run it now. Would like 600rwhp but need help picking a SC pulley size, i am guessing about 7psi of boost?

If you want to run some E make sure you upgrade your fueling to at least LT4 components. 7-8 psi of boost with E40-E60 should get the job done.

[pavetim]

Yeah i plan on using lt4 in tank pump, hpfp, fuel rails, injectors. What size SC pully will take me to 7-8 psi? The SC i am buying has a griptec 2.3" but i know thats too much boost so will be selling that pulley

[pavetim]

Nobody can tell me what pulley for the desired psi?

[KingLT1]

I already did in another thread you posted in.

[THASTIG]

Originally Posted by KingLT1

If you are running 100% meth I would reconsider. Pump gas and meth is a common combination that burns up a lot of these stock LT1's. While the Meth may lower IAT's it is actually increasing cylinder temps and that causes rings to expand. No bueno on a engine with tight ring gaps to begin with. My advice would be to do LT4 fuel system and run E60 and meth. The E will pull heat out of the cylinder and keep the rings from expanding.

I agree that the E85 is a good way to go but water meth injection does not increase cylinder temps it cools them just like E85 would. If your intake air temps are cooler your cylinder and or combustion chamber temps are cooler not to mention the cooling properties of the methanol itself. I personally think its a great additive to any vehicle if its tuned properly

[Joshinator99]

Originally Posted by THASTIG

I agree that the E85 is a good way to go but water meth injection does not increase cylinder temps it cools them just like E85 would. If your intake air temps are cooler your cylinder and or combustion chamber temps are cooler not to mention the cooling properties of the methanol itself. I personally think its a great additive to any vehicle if its tuned properly

You’re mentioning water & meth, while King said 100% meth. Water & meth does pull more heat out and it’s not really the same discussion. I don’t want to speak for King but that part of the conversation really stuck out. It’s not apples-to-apples the same when it comes to heat absorption. 100% meth does not have the same latent heat absorption capacity.

[pavetim]

Sorry king just double checking. Don't wanna spend $175 and not be right so just double checking

[KingLT1]

Originally Posted by Joshinator99

You’re mentioning water & meth, while King said 100% meth. Water & meth does pull more heat out and it’s not really the same discussion. I don’t want to speak for King but that part of the conversation really stuck out. It’s not apples-to-apples the same when it comes to heat absorption. 100% meth does not have the same latent heat absorption capacity.

Exactly...

Originally Posted by THASTIG

I agree that the E85 is a good way to go but water meth injection does not increase cylinder temps it cools them just like E85 would. If your intake air temps are cooler your cylinder and or combustion chamber temps are cooler not to mention the cooling properties of the methanol itself. I personally think its a great additive to any vehicle if its tuned properly

Water does meth does not. Water is the cooling, Meth is the octane. Many end up running a higher percentage of meth for the higher octane which lowers the ability to pull heat from the cylinder. The 30-40degrees lower the IAT reads from the water/meth is really nothing significant in terms of EGT reduction. Most also rely on the Meth system for additional fueling on this platform. This info is out there and has been documented. Forged pistons with proper ring gaps are much more tolerant of heat. The factory LT1 stuff doesn't like the heat. The best way to increase octane on these engines is with Race fuel or Ethanol. Water injection is great for cooling but it doesn't gain any power. Companies like RPM use meth a lot but 99% of the applications are forged and can tolerate the additional heat. Pushing the LT1 to higher power levels with boost on the SBE requires a little different approach in order for the engine to live.

I could put a list together of all the documented SBE LT1 failures and 99% of them would be pump gas / meth combos.

[THASTIG]

Originally Posted by KingLT1

Exactly...



Water does meth does not. Water is the cooling, Meth is the octane. Many end up running a higher percentage of meth for the higher octane which lowers the ability to pull heat from the cylinder. The 30-40degrees lower the IAT reads from the water/meth is really nothing significant in terms of EGT reduction. Most also rely on the Meth system for additional fueling on this platform. This info is out there and has been documented. Forged pistons with proper ring gaps are much more tolerant of heat. The factory LT1 stuff doesn't like the heat. The best way to increase octane on these engines is with Race fuel or Ethanol. Water injection is great for cooling but it doesn't gain any power. Companies like RPM use meth a lot but 99% of the applications are forged and can tolerate the additional heat. Pushing the LT1 to higher power levels with boost on the SBE requires a little different approach in order for the engine to live.

I could put a list together of all the documented SBE LT1 failures and 99% of them would be pump gas / meth combos.

I agree most use it as a form of fueling because they don't have enough to supply the engine with proper amount under higher boost which is not the right way to use it. You should have the fuel system you need to run the boost you want and then use it as a add on for cooling and octane enhancement.

Water will cool the charge but also raises the octane rating of the mixture in the combustion chamber because of its resistance to burn
Methanol does have a higher resistance to detonation but also has a tendency to absorb heat out of the air something known as latent heat of vaporization which is very high with methanol.

I did not notice the 100% methanol on the post which is my mistake but there are a lot or misconceptions out there on this stuff and its always good to discuss these things so we as a group understand it more. We used methanol in the racing industry as a fuel source because of its cooling properties. Hell on certain forced induction applications some guys dont even use an intercooler when running meth because its not needed.

Just to clarify i'm not here to tell anyone they are wrong just share my knowledge and experience.

[Joshinator99]

Originally Posted by THASTIG

I agree most use it as a form of fueling because they don't have enough to supply the engine with proper amount under higher boost which is not the right way to use it. You should have the fuel system you need to run the boost you want and then use it as a add on for cooling and octane enhancement.

Water will cool the charge but also raises the octane rating of the mixture in the combustion chamber because of its resistance to burn
Methanol does have a higher resistance to detonation but also has a tendency to absorb heat out of the air something known as latent heat of vaporization which is very high with methanol.

I did not notice the 100% methanol on the post which is my mistake but there are a lot or misconceptions out there on this stuff and its always good to discuss these things so we as a group understand it more. We used methanol in the racing industry as a fuel source because of its cooling properties. Hell on certain forced induction applications some guys dont even use an intercooler when running meth because its not needed.

Just to clarify i'm not here to tell anyone they are wrong just share my knowledge and experience.

Water has double the latent heat of vaporization that methanol does:
https://www.engineeringtoolbox.com/f...eat-d_147.html

I’m not saying that methanol doesn’t help lower the intake charge because it definitely does, I think we’re all in agreement there. But if getting the chamber temps down is the goal (key to keeping OEM SS pistons alive under boost), then water is a great thing to mix with the meth. E as well, obviously. Or, add forged pistons & all of the above, and you can really rock and roll.

[THASTIG]

Originally Posted by Joshinator99

Water has double the latent heat of vaporization that methanol does:
https://www.engineeringtoolbox.com/f...eat-d_147.html

I’m not saying that methanol doesn’t help lower the intake charge because it definitely does, I think we’re all in agreement there. But if getting the chamber temps down is the goal (key to keeping OEM SS pistons alive under boost), then water is a great thing to mix with the meth. E as well, obviously. Or, add forged pistons & all of the above, and you can really rock and roll.

Well anytime you lower intake temps you having an affect on the whole process. The reason they mix the 2 is because water is a non-combustible so it takes up room in the combustion chamber that can otherwise be occupied by a fuel source.
Oh I know water does, it does a lot of things to aid in engine performance. I was referring to methanol as compared to other fuels.
Regular gasoline can suck out about 150 BTUs of heat energy per pound of fuel, which results in a temperature drop. Methanol takes I think 500 BTUs or so per pound of fuel of heat energy to make the phase change. Its right up there with Ethanol on its ability to absorb heat

I run it in mine at 11-12psi with a 1000cc nozzle starting the injection in at 3psi and its max flow by 10psi, with this my fuel trims stay pretty steady at 11.2-11.5 at WOT. I still am a little nervous it can only do so much lol. The GPI rod and piston kit should be here by the end of the week so im getting ready to yank my motor and install the next phase of parts to get me to my 9sec goal