bent rods again
11-07-2015, 08:43 AM
#21
Let's think about this for a minute! Yes, cylinder 7 or 8 might run warmer, but so what? How much warmer? Does anyone know? I've never heard of an engine bending rods because it ran hot. Let's say the rear cylinders ran 15 degrees hotter than the rest all the time. What if the engine temp came up 15 degrees causing the rest if the cylinders to reach the same temp as the two rears were originally seeing. Would it bend all the rods? Not likely. So that leads me to believer it was a lean issue. It's not a fuel distribution problem unless something is blocking fuel flow to the injectors. All the injectors are at the same spot and fire from the same spot on the intake. It's a "too much air" issue. Some say the air slams into the back of the intake and "overfills" the rear cylinders, which I could understand. Some run the rear cylinders a little richer and pull timing from those cylinders to help cool them down while in boost. Maybe some of those will chime in. If you don't have individual cylinder tuning capabilities though, that wouldn't be possible. Try a colder plug in those cylinders. Have the injectors flowed and put the "healthier" ones in the rear. That's where I'd start.
11-07-2015, 10:08 AM
#22
Pistons all look good. Suprising.
Injectors are the standard ev6 siemen deka 80s.
The meth kit is a 50/50 mix with a single #6 nozzle. I think snow said rated at 600hp. **** i was planning on adding another nozzle to it.
Hear is the deal. I was running 5psi boost steadt with jgs 50mm gate. Line hooked to.bottom. i hooked to top and got steady 20psi boost. I made 4 good hits at that level no.issues. tune looked good no knock, 11.5afr.
Well the next day i drove it and banged limiter 3 times and bent 7 & 8 pretty bad. I did pick up 4° knock while on limiter which may have hurt it as well. Im puzzled between getting another set of gen4 rods or h beams. I would hate to turn it down. Its makes some serious power at 20psi.
Injectors are the standard ev6 siemen deka 80s.
The meth kit is a 50/50 mix with a single #6 nozzle. I think snow said rated at 600hp. **** i was planning on adding another nozzle to it.
Hear is the deal. I was running 5psi boost steadt with jgs 50mm gate. Line hooked to.bottom. i hooked to top and got steady 20psi boost. I made 4 good hits at that level no.issues. tune looked good no knock, 11.5afr.
Well the next day i drove it and banged limiter 3 times and bent 7 & 8 pretty bad. I did pick up 4° knock while on limiter which may have hurt it as well. Im puzzled between getting another set of gen4 rods or h beams. I would hate to turn it down. Its makes some serious power at 20psi.
11-07-2015, 11:14 AM
#23
Here's my opinion, I'd go with another set of gen 4 rods and stay off the limiter. Putting an h-beam in it will help as long as that's the weak link and there's actually no problem. But if it hydro'd, and does again, you'll bend those too. Try and figure out what happened. Spraying meth and being on the limiter may have hydro'd the engine. I know it'd take a ton of water to hydro it, but anythings possible. I want to say another guy here had a Chevelle that banged the limiter and only bent all the drivers side rods. Strange but I want To say he was spraying meth at the same time too. Try and look it up.
11-07-2015, 12:17 PM
#27
Ive got a mech. cobalt boost gauge very accurate. And a 2 bar map. Which i.just thought about is probably my dam problem. I been thinking its on a 3bar tune but its on a 2 bar. Dam.
Im also gonna try maybe straight meth instead. My treadstone intercooler does its job with iat temps. Damn let me get this thing together and give it another shot the correct.way. thanks guys.
Im also gonna try maybe straight meth instead. My treadstone intercooler does its job with iat temps. Damn let me get this thing together and give it another shot the correct.way. thanks guys.
11-07-2015, 02:27 PM
#29
On The Tree
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You can always set your RPM resume to a lot lower RPM. Then when you hit the limiter it gives you time to let off. Don't remember who I got the advice from or id give credit.
HPTuners>Engine>Cutoff, DFCO>Fuel Cutoff RPM vs. Gear>then set the resume to a lot lower RPM.
I set my cutoff to 6,500 and then my resume to 4,500. Then I don't worry about banging off the limiter. If I hit the limiter I just let out. Helps while working on getting my 4l80E to shift at the correct RPM.
John
HPTuners>Engine>Cutoff, DFCO>Fuel Cutoff RPM vs. Gear>then set the resume to a lot lower RPM.
I set my cutoff to 6,500 and then my resume to 4,500. Then I don't worry about banging off the limiter. If I hit the limiter I just let out. Helps while working on getting my 4l80E to shift at the correct RPM.
John
11-07-2015, 02:38 PM
#30
FWIW there is no way you'll ever hydro lock a motor with a standard water/meth kit. 50/50 or even straight water... not gonna happen.
If you have a 2 bar map, the tune is gonna flat line at 14.7 lbs. Hard to believe your AFR stayed steady at 20lbs with a 2 bar map. That woudl mean teh engein was using the same amount of fuel at 14.7 as it was at 20.
If you have a 2 bar map, the tune is gonna flat line at 14.7 lbs. Hard to believe your AFR stayed steady at 20lbs with a 2 bar map. That woudl mean teh engein was using the same amount of fuel at 14.7 as it was at 20.