Ahmedi911

I have c7 2016 z51 a8 mods procharger(d1sc) meth(alky dn) and headers (178 tsp)
it’s on 6 psi making 560 whp i want to turn the boost up to 10 will the stock bottom end handle this power and the fuel system ? around how many whp it will be any suggestions?

us3rname

I'm at 9.5psi with an lt4 blower, injectors and pump and its at 630rwhp. Best bet would be to talk to your tuner and see what they recommend at 560 there is definitely more left in it.

Bruce_K

Dont forget @us3rname your using meth as well.

I think i got about 560 without upgrading the fuel, I think im pushing 12psi through the stock bottom end.

us3rname

yeah, I still haven't been on the dyno after installing the alky kit so no idea what its making now. Also edited my original post since I forgot to add that I've got the lt4 injectors and hpfp.

robert miller

I think if you are at 12 psi you will have problems IF you do much really hard WOT.. The crank in these cars are forged & good THE WEAK POINT HERE IS THE PISTONS.. The ring gap with them being non forged the ring gap is just to closed for a blown set up..... Robert

0Billy@MTI

Your at the limit on the pistons at our shop and the fuel system. The rods are good to 850hp.
Billy

Bruce_K

Robert you've chimed in on my post before. I know the weakness of the LT1 I'm very aware. I'm running 660whp at 12 Psi all year. If it blows it blows.
I'm ready to build it if it happens.

Thanks again.

us3rname

I'm going on about 8 months on my set up with zero issues. I think a lot of people who pop these motors put the blame on component weakness when it was probably a crap tune. I think Cletus McFarland is over 1000 rwhp on his stock bottom lt1 and its still kicking event after being over 800rwhp for god knows how long.

0Billy@MTI

The ring gaps are very tight. Thats what causes the ring lands to break. I can't tell you how one persons motor is alive at those power levels, but if you looks at the ones that have piston failures. They are all at the mid 600 range and higher.
Billy

BrunoTheMellow

Jeez. You might lose your whole block because you don't want to do drop in pistons now? Wow.

0Billy@MTI

Everyone that we a had come in with a broken ring land, it doesn't hurt the block. The ring land between the top and second ring break.

Bruce_K

Thanks for chiming in Billy.

I dont get why everyone is so concerned with what I am doing. I understand the risk. and when and if it blows I'll get it fixed. Im not even 100% sure what i what to do either get pistons or just get a 416. Like i said before i know the risks. When its time to pop in a cam and dismantle the engine i'll do it all once. if it survives LOL

us3rname

Are you noticing any trends as to what years are experiencing the most failures. I was reading some posts on the Camaro 6 forum that they claim the quality of the pistons have improved throughout the years. Not saying that is the case but am wondering if there is any truth to that statement.

0Billy@MTI

Its not a problem with the build quality. Its that the LT1's rings are gapped very tight. They all have this issue. For example the stk gaps are as tight as .012. The we do install pistons we set the gaps as high as .022. Give the ring room to grow under hight cylinder pressures.
Billy

0Billy@MTI

Welcome and we will form time to time have a customer as yourself that knows the risks and will go mid 600s.
Billy

BrunoTheMellow

Ah. Thanks. I always thought any breaking of the internals had a good chance of scoring everything around it.

Joshinator99

If you want your LT1 short block to live on boost, then your main concern should be fueling! LT4 in-tank, LT4 HPFP, and LT4 injectors are the bare minimum to run a blower IMO. It’s not just about A/F ratio, you have a very narrow injection window in which to squirt the fuel. Keep your injector pulsewidth under 6.0 ms and if you can, run a little E (E30/E40) to help pull heat out of the chamber. You won’t be able to do that with stock LT1 fuel components and under boost. Running lean and/or detonation will kiss your factory LT1 pistons goodbye. So watch your rail and low side fuel pressures while you tune it in. If those pressures drop, reassess your situation before turning up the boost.

Bruce_K

I have all those things Josh! Thanks for the input!

C7&7

At 700 wheel or 10+ PSI you need pistons. Anything between 550 and 700 you need meth and or LT4 fueling. HOWEVER....it better be tuned right or like MTI is alluding to you're going to damage a piston.

robert miller

This is what I have read also Billy & agree 100% just crazy to me like the above guy has said I am sure over 50% of it is what a so called tuner has put into the tune on the car also is part of it. But with that said it is still the parts that are the weak point of this motor with a blower on it.

I am just diff if I am going to do this I will replace every dam part in the car to HOPE & try to make sure it sticks together.. Thanks for all your info in the past great shop & vendor here.. Robert