[JANNETTYRACING]

Originally Posted by adamjwilson

I beg to differ on your OPINION only. Have seen (2) Gen 6s break pistons with less than 800 HP. (The weak link is those stock alum pistons.) Why do you think GM went with forged internals on the ZL1? Have YOU seen broken forged pistons with less than 900-1000 whp? I haven't, if TUNED correctly and driver not doing stupid sh## (like you state above, combinations and tuning makes ALL the difference)
If you are going to pawn your goods on this forum (especially for ~$20K for your 'brawler' package without pistons), please give data that is helpful to those looking for guidance... (stick to the original question asked)

If they broke there was Detonation.

I agree the pistons are the susceptible to detonation where a forged piston might tolerate some.

The key is don't have any, make sure you have adequate fuel supply for the target HP.

[adamjwilson]

Originally Posted by JANNETTYRACING

If they broke there was Detonation.

I agree the pistons are the susceptible to detonation where a forged piston might tolerate some.

The key is don't have any, make sure you have adequate fuel supply for the target HP.

Totally agree! What concerns me is your comment "An Lt1 can live a happy life at 900 HP if done right." with stock internals? for how long?

[adamjwilson]

Originally Posted by Katech_Mike

We don't like to push stock LT1 shortblocks much further than 700RWHP on E85 for durability reasons.

On pump gas I really don't even like to push them past about 650RWHP.

I would recommend upgrading to a forged shortblock if you want to make more than 700RWHP. We offer a good budget forged shortblock that will take 1,000RWHP.

Solid advice!

[JANNETTYRACING]

Originally Posted by adamjwilson

Totally agree! What concerns me is your comment "An Lt1 can live a happy life at 900 HP if done right." with stock internals? for how long?

Only something I would do for myself an never for a customer.

Think about this, the LT1 is a stronger engine than the LS3.

[adamjwilson]

Originally Posted by JANNETTYRACING

Only something I would do for myself an never for a customer.

Think about this, the LT1 is a stronger engine than the LS3.

Thanks for the clarification.

[asthmamax11]

Low boost + headers + E60 can make a reliable and consistent 600whp with proper tuning

[Joshinator99]

Originally Posted by Katech_Mike

We don't like to push stock LT1 shortblocks much further than 700RWHP on E85 for durability reasons.

On pump gas I really don't even like to push them past about 650RWHP.

I would recommend upgrading to a forged shortblock if you want to make more than 700RWHP. We offer a good budget forged shortblock that will take 1,000RWHP.

CAN you push a SBE LT1 past 700 WHP? Of course. Now, is it a GOOD IDEA? Nope. You’re taking inferior pistons and rods designed to handle ~380-400 WHP from the factory and asking them to routinely hold up to 200% load conditions. It can be done, sure, but long term you’re simply playing losing odds. Just my 2 cents of course, but seeing all the builds on this board for the 4-5 years has painted a pretty clear picture IMO.

[KingLT1]

Originally Posted by Joshinator99

CAN you push a SBE LT1 past 700 WHP? Of course. Now, is it a GOOD IDEA? Nope. You’re taking inferior pistons and rods designed to handle ~380-400 WHP from the factory and asking them to routinely hold up to 200% load conditions. It can be done, sure, but long term you’re simply playing losing odds. Just my 2 cents of course, but seeing all the builds on this board for the 4-5 years has painted a pretty clear picture IMO.

I agree but I believe if the rings were gapped for boost the LT1 rotator would probably go as far as the thrust bearing would allow with a crank driven supercharger. You still have to keep detonation in check also. High cylinder pressure from the high compression will bend rods, spin bearings, and break pistons under load with very little knock. The forged stuff simply provides more cushion for improper tuning. You wouldn't believe all of the gen 5 LT builds shops are putting out on the street that are out of fuel and knocking. I get PM's all the time asking "hey would you look over my tune X shop did this" and usually first thing I see is Injectors 6.0ms +.

[Joshinator99]

Originally Posted by KingLT1

I agree but I believe if the rings were gapped for boost the LT1 rotator would probably go as far as the thrust bearing would allow with a crank driven supercharger. You still have to keep detonation in check also. High cylinder pressure from the high compression will bend rods, spin bearings, and break pistons under load with very little knock. The forged stuff simply provides more cushion for improper tuning. You wouldn't believe all of the gen 5 LT builds shops are putting out on the street that are out of fuel and knocking. I get PM's all the time asking "hey would you look over my tune X shop did this" and usually first thing I see is Injectors 6.0ms +.

Totally agree. If you’re gonna pull the pistons to regap the rings, might as well just do the drop ins at that point. Like you said, forged gives you a good bit more leeway.

[oldman]

Originally Posted by KingLT1

I agree but I believe if the rings were gapped for boost the LT1 rotator would probably go as far as the thrust bearing would allow with a crank driven supercharger. You still have to keep detonation in check also. High cylinder pressure from the high compression will bend rods, spin bearings, and break pistons under load with very little knock. The forged stuff simply provides more cushion for improper tuning. You wouldn't believe all of the gen 5 LT builds shops are putting out on the street that are out of fuel and knocking. I get PM's all the time asking "hey would you look over my tune X shop did this" and usually first thing I see is Injectors 6.0ms +.

Yep

With fuel within the 6ms good power is found, past 6ms and power gets iffy. I’m boosted E85, ligenfelter fuel system (pump, injectors), second fuel pump lp side. Forged engine, I feel sooner or later the hollow 4th journal LT1 crank is going byebye. I’m at 7400 rpm fuel cut just so I don’t need to shift till 62 mph, for in my own mind game mid to low 3 second 0- 60 fun, engine does sound great at 7400. My car hit 7 years old today same engine trans rear. Nutshell so far all good but if I were to do it again, I’d get a lt4 or aftermarket crank at my power level, D1x, cam, built engine.

[cmitchell17]

Originally Posted by Joshinator99

CAN you push a SBE LT1 past 700 WHP? Of course. Now, is it a GOOD IDEA? Nope. You’re taking inferior pistons and rods designed to handle ~380-400 WHP from the factory and asking them to routinely hold up to 200% load conditions. It can be done, sure, but long term you’re simply playing losing odds. Just my 2 cents of course, but seeing all the builds on this board for the 4-5 years has painted a pretty clear picture IMO.

So I don't know this and this is an assumption but I would be willing to bet the internal engine components are built on a safety factor past 2 and probably around 3. Of course though I bet they have more difficulty meeting fatigue strength rather than ultimate strength requirements as I would think they would design for infinite cycle life. So basically they have to make sure the part is strong enough to resist a smaller amount of stress than peak expected stress over millions or basically an infinite amount of cycles. When they make it strong enough to have low enough stress at the non peak fatigue load conditions (think just the loading from the weight of the rotating assembly while running at highway RPMs not even considering combustion or any other loading) I bet it makes it even stronger to resist the ultimate loading we would be putting on it pushing big power.

Of course GM or any OEM would say any mods will be bad and destroy it and reduce engine life the thing is they design these things for extreme conditions, like running WOT for months on end simulating towing up a step grade at full power and stuff like that. In addition what if there is a design or material defect in one of the rods or pistons or too sharp of a radius that gets carried through millions of parts, it's cheap insurance to over design it instead of having to do millions of warranty claims.

When people modify these things although they might think they are doing everything perfect, they are introducing all kinds of variables (clearances, improper assembly, non-oem parts, etc) and deviating from a tightly controlled OEM environment and as like people said basically tuning it blindly while thinking a wideband O2 feedback Will give them all the information they need.

Like someone else said as well the GEN V platform was designed stronger than the GEN IV as GM increased the power output so they had to correspondingly increase the safety factor and probably meet the same durability requirements as before.

[Joshinator99]

Originally Posted by cmitchell17

So I don't know this and this is an assumption but I would be willing to bet the internal engine components are built on a safety factor past 2 and probably around 3. Of course though I bet they have more difficulty meeting fatigue strength rather than ultimate strength requirements as I would think they would design for infinite cycle life. So basically they have to make sure the part is strong enough to resist a smaller amount of stress than peak expected stress over millions or basically an infinite amount of cycles. When they make it strong enough to have low enough stress at the non peak fatigue load conditions (think just the loading from the weight of the rotating assembly while running at highway RPMs not even considering combustion or any other loading) I bet it makes it even stronger to resist the ultimate loading we would be putting on it pushing big power.

Of course GM or any OEM would say any mods will be bad and destroy it and reduce engine life the thing is they design these things for extreme conditions, like running WOT for months on end simulating towing up a step grade at full power and stuff like that. In addition what if there is a design or material defect in one of the rods or pistons or too sharp of a radius that gets carried through millions of parts, it's cheap insurance to over design it instead of having to do millions of warranty claims.

When people modify these things although they might think they are doing everything perfect, they are introducing all kinds of variables (clearances, improper assembly, non-oem parts, etc) and deviating from a tightly controlled OEM environment and as like people said basically tuning it blindly while thinking a wideband O2 feedback Will give them all the information they need.

Like someone else said as well the GEN V platform was designed stronger than the GEN IV as GM increased the power output so they had to correspondingly increase the safety factor and probably meet the same durability requirements as before.

That is complete guess work, as I’m sure you’ll agree. I would bet a substantial amount of money that a penny pinching outfit like GM would never engineer a safety factor of 3 into those pistons and rods. You’re welcome to shoot for 1365 HP (455 x 3) on your build with OEM LT1 pistons but I’m going to take a hard pass. You might get one pull out of it…

[adamjwilson]

Originally Posted by Joshinator99

That is complete guess work, as I’m sure you’ll agree. I would bet a substantial amount of money that a penny pinching outfit like GM would never engineer a safety factor of 3 into those pistons and rods. You’re welcome to shoot for 1365 HP (455 x 3) on your build with OEM LT1 pistons but I’m going to take a hard pass. You might get one pull out of it…

I will take that bet too... count me in

[laynlo15]

We safely made 707/662 on the stock Lt1 long block with a 2300 Maggie, Toohighpsi Port Injection, stock exhaust on E65. We did use the JMS boost pump but the rest of the fueling is from the stock High and low side fuel system. We also ran 9.86@142 with this set up on stock suspension except for Phastek lowered springs, lost 100 lbs with the drag pack which for sure helps out on the ET and MPH with less rotating mass.