Stock bottom end hp limit - Page 2

Turbo_RORO · 12-04-2017, 10:08 AM

Quote:

Originally Posted by ShizzySupra

Agree on most points but the LT1 is also a full point of compression higher as well. If I am opening up the bottom end its getting pistons/rods.

Preach!

jessrayo · 12-04-2017, 11:33 AM

What the motor can handle depends a lot on what you do with the car. If all you do is dyno runs and very short bursts of throttle I'll bet it can take 850 on a dyno run. My stock block dyno did 750+ whp no problem. But based on all the ring and piston failure I decided 750whp would not be safe if I took the car to racing venues and ran it all out. I dialed it back to around 650whp and did several drag runs and speed runs over 190mph without engine failure. But at that 650 level I took it to the road course and ran it flat out for 20 minutes then had a piston failure. Maybe 600 would have held at the road course I don't know. Now I kind of feel it is ticking time bomb over 600. Of course there are minor differences in every engine, no two castings are exactly the same. There will be some variation of maybe as much as 100 whp tolerance. I'm recommending forged internals over 600whp to anyone that asks me.

JANNETTYRACING · 12-04-2017, 01:22 PM

Quote:

Originally Posted by jessrayo

What the motor can handle depends a lot on what you do with the car. If all you do is dyno runs and very short bursts of throttle I'll bet it can take 850 on a dyno run. My stock block dyno did 750+ whp no problem. But based on all the ring and piston failure I decided 750whp would not be safe if I took the car to racing venues and ran it all out. I dialed it back to around 650whp and did several drag runs and speed runs over 190mph without engine failure. But at that 650 level I took it to the road course and ran it flat out for 20 minutes then had a piston failure. Maybe 600 would have held at the road course I don't know. Now I kind of feel it is ticking time bomb over 600. Of course there are minor differences in every engine, no two castings are exactly the same. There will be some variation of maybe as much as 100 whp tolerance. I'm recommending forged internals over 600whp to anyone that asks me.

Well Said, no one can argue with your experience.

Ted.

ProCharger · 12-04-2017, 04:12 PM

Ring gap will be the issue. In my humble opinion

You never know if yours is the tight one, or the loose one.

I have personally done 800+ and lived, as well as coyotes at over 900 and lived.
However, the ones that live only get raced 1/4 or 1/8th mile at a time.

Nobody that I haved tuned lives on 200mph highway pulls racing bikes.
(even when tuned the same as the higher HP cars)

Every failure I have had was from pinched rings.
I have yet to bend/break/crush a rod, or have bearing issues.
(or even break a piston from flat out HP)

I personally would love to open a motor up, gap the rings correctly, and put it back together... (which is what I will do with my personal 2018) And never think about it again.

12-04-2017, 11:33 AM	#16
jessrayo Speed Freak Drives: 2013 ZL1 Camaro, 2016 Camaro SS Join Date: Jun 2013 Location: Ardmore, OK Posts: 2,637 View My Garage	What the motor can handle depends a lot on what you do with the car. If all you do is dyno runs and very short bursts of throttle I'll bet it can take 850 on a dyno run. My stock block dyno did 750+ whp no problem. But based on all the ring and piston failure I decided 750whp would not be safe if I took the car to racing venues and ran it all out. I dialed it back to around 650whp and did several drag runs and speed runs over 190mph without engine failure. But at that 650 level I took it to the road course and ran it flat out for 20 minutes then had a piston failure. Maybe 600 would have held at the road course I don't know. Now I kind of feel it is ticking time bomb over 600. Of course there are minor differences in every engine, no two castings are exactly the same. There will be some variation of maybe as much as 100 whp tolerance. I'm recommending forged internals over 600whp to anyone that asks me. __________________ 2016 SS -AGP twin Borg Warner 7163 EFR's, LT4 mechanical pump, LT4 injectors, Walbro 255 low side, Castrol SRF. 734whp/759 tq 2013 ZL1 -ADM - 427 LSX 6 bolt, O-ringed block built by LME. Twin PT6466 turbos. RPM custom manual trans, RPS Quad carbon clutch, 9" Hendrix rear diff & axles. ADM/squash fuel system, Ron Davis radiator, Spal fans, AGP air to air, turbo plumbing. LPE oil cooler, rear bushing upgrade, roll bar...etc. rwhp 1400+... 212.5mph, best Texas mile to date.

12-04-2017, 04:12 PM	#18
ProCharger Drives: Many C7's Join Date: Apr 2014 Location: Kansas City Posts: 573	Ring gap will be the issue. In my humble opinion You never know if yours is the tight one, or the loose one. I have personally done 800+ and lived, as well as coyotes at over 900 and lived. However, the ones that live only get raced 1/4 or 1/8th mile at a time. Nobody that I haved tuned lives on 200mph highway pulls racing bikes. (even when tuned the same as the higher HP cars) Every failure I have had was from pinched rings. I have yet to bend/break/crush a rod, or have bearing issues. (or even break a piston from flat out HP) I personally would love to open a motor up, gap the rings correctly, and put it back together... (which is what I will do with my personal 2018) And never think about it again.

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