Blown Motor, Engine Rebuild/Replacement.

phunk · 02-10-2014, 12:21 AM

I agree that there are several contributing factors to having an issue there. I'll state that my fuel systems that include rails all use -8 plumbing up to a Y split to twin -6. The rails bores are smaller than I desire for adequate fitment in a type space. We aren't going to see -8 rails fitting under a stock intake manifold so while I won't argue that it could be an alternate fix, it's not an option for the typical VQ. (BTW I know of a 370 with custom manifold and -8 rails and it's suffering rail resonance hesitations). My kits on the DE all used -6 Aeromotive regulators which I find appropriately sized for the general walbro 255 that the majority of customers use. I personally tried different fuel pressures in my 350z to no remedy. Having to make new rails was the last thing I wanted to do as i had concerns of being overwhelmed with people asking for replacements.

I'd go out on a limb and say that I doubt most race cars have them because they don't spend much time at those RPM/load sites where it causes hesitation. It is my opinion that there are probably many people suffering of the resonance and completely unaware as they probably credit it to tuning or other issue.

1slow370 · 02-10-2014, 01:25 AM

Quote:

Originally Posted by phunk

I agree that there are several contributing factors to having an issue there. I'll state that my fuel systems that include rails all use -8 plumbing up to a Y split to twin -6. The rails bores are smaller than I desire for adequate fitment in a type space. We aren't going to see -8 rails fitting under a stock intake manifold so while I won't argue that it could be an alternate fix, it's not an option for the typical VQ. (BTW I know of a 370 with custom manifold and -8 rails and it's suffering rail resonance hesitations). My kits on the DE all used -6 Aeromotive regulators which I find appropriately sized for the general walbro 255 that the majority of customers use. I personally tried different fuel pressures in my 350z to no remedy. Having to make new rails was the last thing I wanted to do as i had concerns of being overwhelmed with people asking for replacements.

I'd go out on a limb and say that I doubt most race cars have them because they don't spend much time at those RPM/load sites where it causes hesitation. It is my opinion that there are probably many people suffering of the resonance and completely unaware as they probably credit it to tuning or other issue.

Good post it did a lot to back up your arguments, I understand the point of dampeners and i don't disagree with you on them, just that not every car needs them to perform and drive well. Also since if they happen it is at a point when the engine usually isn't getting a lot of boost and so low in the range that to a lot of people even if they notice it, it really isn't even that big of a problem, to some it is, hell the factory traction control is WAY more annoying.

phunk · 02-10-2014, 01:30 AM

I wish I had a video to show you how bad my 350z would buck and hesitate if you tried to hold it at 2400 or 3100 rpm. Just standard cruising around town you pass these rpms all the time. It's annoyance was cumulative and you sort of learn to drive around it. But I'll tell ya, it was bad! 17s AF and jerking and bucking until you either push thru the RPM or backed off it by up shifting. The potential for this severity of problems is why we just said skip it and put the dampers back in. Tons of my customers never did have a noticeable problem though. In that thread linked you can see the guy who started to chase it and datalogging it noticed that while putting the setup back to stock dampening solved the drivability problems, but he could still see it in logging and he eventually added one more additional damper over stock.

COSMO · 02-10-2014, 05:50 AM

Great here we go again...

COSMO · 02-10-2014, 11:33 AM

I managed to get a little more prep ready for the engine to be pulled out tomorrow. Here are a few pics and yes that is metal chunks sitting on top of the valves..

Chuck33079 · 02-10-2014, 12:11 PM

What part broke, piston or rod?

Dzel · 02-10-2014, 12:47 PM

Damn!

Sent with TapAhoe

DEpointfive0 · 02-10-2014, 01:18 PM

Wellllllll... If need... I have a left side valve head assembly

Good luck, I hope you won't need it

zguynate · 02-10-2014, 01:31 PM

Im sure it looks worse than it actually is, but that process looks like a nightmare lol.

COSMO · 02-10-2014, 01:46 PM

The motor will be out tomorrow and I'll will know for sure but I'm guessing a rod. The valves are intact...

Quote:

Originally Posted by Chuck33079

What part broke, piston or rod?

COSMO · 02-10-2014, 01:54 PM

It's not that bad at all since I have done 4 Twin Turbo installs..

Quote:

Originally Posted by dragonbreath

Im sure it looks worse than it actually is, but that process looks like a nightmare lol.

COSMO · 02-10-2014, 02:04 PM

I'm curious to see if I find any Cracks on the exhaust manifolds... Stay Tuned!!

DIGItonium · 02-10-2014, 02:45 PM

How long have you had your FI setup? Those valves are clean. I need to get catch cans for mine since I have this paranoia with oil blow by. I need to pull stuff apart to clean it once the weather gets warmer.

COSMO · 02-10-2014, 02:51 PM

I have about 3-4k on the TT Kit..

Quote:

Originally Posted by DIGItonium

How long have you had your FI setup? Those valves are clean. I need to get catch cans for mine since I have this paranoia with oil blow by. I need to pull stuff apart to clean it once the weather gets warmer.

COSMO · 02-10-2014, 03:59 PM

As if I don't have enough things to do already look what came in today from Z1.. lol

02-10-2014, 12:21 AM	#301 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,667 Drives: 370 Rep Power: 971367	I agree that there are several contributing factors to having an issue there. I'll state that my fuel systems that include rails all use -8 plumbing up to a Y split to twin -6. The rails bores are smaller than I desire for adequate fitment in a type space. We aren't going to see -8 rails fitting under a stock intake manifold so while I won't argue that it could be an alternate fix, it's not an option for the typical VQ. (BTW I know of a 370 with custom manifold and -8 rails and it's suffering rail resonance hesitations). My kits on the DE all used -6 Aeromotive regulators which I find appropriately sized for the general walbro 255 that the majority of customers use. I personally tried different fuel pressures in my 350z to no remedy. Having to make new rails was the last thing I wanted to do as i had concerns of being overwhelmed with people asking for replacements. I'd go out on a limb and say that I doubt most race cars have them because they don't spend much time at those RPM/load sites where it causes hesitation. It is my opinion that there are probably many people suffering of the resonance and completely unaware as they probably credit it to tuning or other issue. __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph Last edited by phunk; 02-10-2014 at 12:26 AM.

02-10-2014, 01:30 AM	#303 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,667 Drives: 370 Rep Power: 971367	I wish I had a video to show you how bad my 350z would buck and hesitate if you tried to hold it at 2400 or 3100 rpm. Just standard cruising around town you pass these rpms all the time. It's annoyance was cumulative and you sort of learn to drive around it. But I'll tell ya, it was bad! 17s AF and jerking and bucking until you either push thru the RPM or backed off it by up shifting. The potential for this severity of problems is why we just said skip it and put the dampers back in. Tons of my customers never did have a noticeable problem though. In that thread linked you can see the guy who started to chase it and datalogging it noticed that while putting the setup back to stock dampening solved the drivability problems, but he could still see it in logging and he eventually added one more additional damper over stock. __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph Last edited by phunk; 02-10-2014 at 01:35 AM.

02-10-2014, 05:50 AM	#304 (permalink)
COSMO A True Z Fanatic Join Date: Dec 2012 Location: FL Posts: 1,816 Drives: 2012 Touring GTM TT Rep Power: 19	Great here we go again... elperuano and Chuck33079 like this.

02-10-2014, 12:11 PM	#306 (permalink)
Chuck33079 A True Z Fanatic Join Date: Nov 2011 Location: Houston Posts: 12,265 Drives: 2011 370ztt Rep Power: 29538	What part broke, piston or rod? __________________ 2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

02-10-2014, 12:47 PM	#307 (permalink)
Dzel A True Z Fanatic Join Date: May 2011 Location: Midland, TX Posts: 3,884 Drives: 11 370Z PW M6 Rep Power: 23	Damn! Sent with TapAhoe __________________ 10secWS6 IF YOU CAN'T SWING IT THEN DON'T BRING IT! Check out Domestic Performance C.C.

02-10-2014, 01:18 PM	#308 (permalink)
DEpointfive0 Premium Member Bitches Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17151	Wellllllll... If need... I have a left side valve head assembly Good luck, I hope you won't need it COSMO likes this. __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language:

02-10-2014, 01:31 PM	#309 (permalink)
zguynate A True Z Fanatic Join Date: Jan 2012 Location: Strangeland Posts: 1,054 Drives: 09 370z Rep Power: 73	Im sure it looks worse than it actually is, but that process looks like a nightmare lol. __________________ 2009 370z touring w/sports package

02-10-2014, 02:04 PM	#312 (permalink)
COSMO A True Z Fanatic Join Date: Dec 2012 Location: FL Posts: 1,816 Drives: 2012 Touring GTM TT Rep Power: 19	I'm curious to see if I find any Cracks on the exhaust manifolds... Stay Tuned!!

02-10-2014, 02:45 PM	#313 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	How long have you had your FI setup? Those valves are clean. I need to get catch cans for mine since I have this paranoia with oil blow by. I need to pull stuff apart to clean it once the weather gets warmer. __________________

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