The reason the VQ35 breaks with FI
12-06-2006, 12:23 PM
#1
Registered User
Thread Starter
iTrader: (6)
Join Date: Aug 2004
Location: SoCal
Posts: 245
Likes: 0
Received 0 Likes
on
0 Posts
The reason the VQ35 breaks with FI
Well, ive been part of this forum for awhile, had a vortech at one time, but I havent payed attn to the FI for awhile..... have we found out EXACTLY what causes the motors to blow? Sorry if has been found but I didnt see anything new while searching..
Im pretty sure rods go first, but I remember APS claiming that the rod bearings dont get enough oil which causes them to heat up, seize, and then the rods break... This doesnt exactly seem correct, because people with built motors are using the same oil design, with oem bearings and achieve 600+whp
Although I see A LOT of built motors blowing...
Is the weak point strictly the rods?
Im pretty sure rods go first, but I remember APS claiming that the rod bearings dont get enough oil which causes them to heat up, seize, and then the rods break... This doesnt exactly seem correct, because people with built motors are using the same oil design, with oem bearings and achieve 600+whp
Although I see A LOT of built motors blowing...
Is the weak point strictly the rods?
12-06-2006, 12:27 PM
#2
Registered User
iTrader: (18)
Join Date: Oct 2004
Location: .
Posts: 9,482
Likes: 0
Received 0 Likes
on
0 Posts
No exact cause has been confirmed, but there are multiple theories. I doubt it is as simple as simply weak stock rods.
I don't see many built motors blowing... Where are you seeing these? The only issue I've seen to plague built motors was headlift/blown headgaskets but that's since been resolved.
I don't see many built motors blowing... Where are you seeing these? The only issue I've seen to plague built motors was headlift/blown headgaskets but that's since been resolved.
12-06-2006, 12:33 PM
#3
Registered User
Thread Starter
iTrader: (6)
Join Date: Aug 2004
Location: SoCal
Posts: 245
Likes: 0
Received 0 Likes
on
0 Posts
Well, theres a few local guys that have blown their built motors, I believe one guy just blew his second built motor. I cant confirm he was running it properly, just heard he blew it.
Thx for the reply, I wish we knew exaclty what the weak point was, you would think we would have the answer by now, are boosted revup motors holding up better than 287's??
Thx for the reply, I wish we knew exaclty what the weak point was, you would think we would have the answer by now, are boosted revup motors holding up better than 287's??
12-06-2006, 12:38 PM
#4
Registered User
iTrader: (3)
Join Date: Sep 2006
Location: Canada
Posts: 744
Likes: 0
Received 0 Likes
on
0 Posts
well if the guy has blown a second motor I guess the defect is the instal, tune, or more than likely driver abuse.
also i have heard stock motors 03 - 05 have weak rod bolts which is why the 06 have stronger ones, I think??
also i have heard stock motors 03 - 05 have weak rod bolts which is why the 06 have stronger ones, I think??
12-06-2006, 01:00 PM
#7
Registered User
iTrader: (16)
Join Date: Mar 2004
Location: Nashville, TN
Posts: 2,939
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by clemlover15
at 16psi I hope we sleeved and should have been running F-CON
Trending Topics
12-06-2006, 01:38 PM
#8
Registered User
Join Date: Sep 2005
Location: moore, ok
Posts: 176
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by clemlover15
well if the guy has blown a second motor I guess the defect is the instal, tune, or more than likely driver abuse.
also i have heard stock motors 03 - 05 have weak rod bolts which is why the 06 have stronger ones, I think??
also i have heard stock motors 03 - 05 have weak rod bolts which is why the 06 have stronger ones, I think??
Yeah the 06 got a bolt in the rod (I think so dose the 05, REVUP)
12-06-2006, 04:43 PM
#10
Open decks really only distort at high rpms not directly from cylinder pressure. There are open deck 2.5l inline porsche engines making like 600whp, they dont break cylinders.... Just trannys you have shift right, so the rpms dont hit the tq peak while getting on it from the shift. If that makes any sense.
12-06-2006, 08:54 PM
#11
yes, rods are the weak point. the beam is only about as thick as your pointer finger! second is pistons. very small ring lands.
gotta remember this is the same motor they use in the quest! the only guys making a stock motor last is retarding the timing large amounts so it fires on the way back down and not at the peak of compression.
when i pulled my stock block apart, i had 5 bent rods and 4 different pistons with broken ring lands. yes, visibly bent.
i know your still fairily new to the forum, but yes, this info was found 1.5-2 years ago with not much talk about it since. some searches on headlift/combustion leaks is the main battle at this point.
gotta remember this is the same motor they use in the quest! the only guys making a stock motor last is retarding the timing large amounts so it fires on the way back down and not at the peak of compression.
when i pulled my stock block apart, i had 5 bent rods and 4 different pistons with broken ring lands. yes, visibly bent.
i know your still fairily new to the forum, but yes, this info was found 1.5-2 years ago with not much talk about it since. some searches on headlift/combustion leaks is the main battle at this point.
12-06-2006, 09:06 PM
#12
Originally Posted by rocks
Open decks really only distort at high rpms not directly from cylinder pressure. There are open deck 2.5l inline porsche engines making like 600whp, they dont break cylinders.... Just trannys you have shift right, so the rpms dont hit the tq peak while getting on it from the shift. If that makes any sense.
12-07-2006, 05:12 AM
#13
Registered User
Join Date: Oct 2003
Location: Marietta, Georgia
Posts: 984
Likes: 0
Received 0 Likes
on
0 Posts
Why would any engineer chance the accountants wrath by over designing any NA engine to tolerate over pressure from boost for long - a pure waste of money proving the engineer is unfit to keep his job.
The cheapest parts that will do the job [make it thru warranty and 100k which ever is sooner] is what mass production is all about.
Computers have enabled maunfacturers to wring out all the waste of yore, where you overbuilt, as the easiest method of creating longevity.......this wasteful concept was dropped im the mid 90's designs which went into production in 2002.
Look back at the J30/300zx engine [castiron block] even in it's mild boosted form almost every internal component was different and strengthened.
Hopefully the engineers use every stock internal failure on the web as proof they did their job well and frugally! See boss another one bit the dust see how good I am...........not a gram of extra weight in any of MY DESIGNS.
The cheapest parts that will do the job [make it thru warranty and 100k which ever is sooner] is what mass production is all about.
Computers have enabled maunfacturers to wring out all the waste of yore, where you overbuilt, as the easiest method of creating longevity.......this wasteful concept was dropped im the mid 90's designs which went into production in 2002.
Look back at the J30/300zx engine [castiron block] even in it's mild boosted form almost every internal component was different and strengthened.
Hopefully the engineers use every stock internal failure on the web as proof they did their job well and frugally! See boss another one bit the dust see how good I am...........not a gram of extra weight in any of MY DESIGNS.
12-07-2006, 06:28 AM
#14
Registered User
iTrader: (154)
Join Date: Jun 2003
Location: Hills of Anaheim
Posts: 10,735
Likes: 0
Received 0 Likes
on
0 Posts
You'd think that Nissan's US flagship would at least have something that the Quest or Maxima doesn't have. Too bad Nissan doesn't care as much about the Z as they do the Skyline.
12-07-2006, 07:25 AM
#15
Turbo Whore
iTrader: (4)
Join Date: Oct 2002
Location: West suburbs of Chi-town
Posts: 7,303
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by overZealous1
yes, rods are the weak point. the beam is only about as thick as your pointer finger! second is pistons. very small ring lands.
gotta remember this is the same motor they use in the quest! the only guys making a stock motor last is retarding the timing large amounts so it fires on the way back down and not at the peak of compression.
when i pulled my stock block apart, i had 5 bent rods and 4 different pistons with broken ring lands. yes, visibly bent.
i know your still fairily new to the forum, but yes, this info was found 1.5-2 years ago with not much talk about it since. some searches on headlift/combustion leaks is the main battle at this point.
gotta remember this is the same motor they use in the quest! the only guys making a stock motor last is retarding the timing large amounts so it fires on the way back down and not at the peak of compression.
when i pulled my stock block apart, i had 5 bent rods and 4 different pistons with broken ring lands. yes, visibly bent.
i know your still fairily new to the forum, but yes, this info was found 1.5-2 years ago with not much talk about it since. some searches on headlift/combustion leaks is the main battle at this point.
You can speculate all you want but power isn't what typically causes a con rod to break or bend. Detonation and excessive revolustions are much more likely culprits.
All that said, my stock motor is coming out of my car this weekend. It's still in perfect running condition..but I have bigger plans for the spring.
12-07-2006, 07:27 AM
#16
Turbo Whore
iTrader: (4)
Join Date: Oct 2002
Location: West suburbs of Chi-town
Posts: 7,303
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by Q45tech
Why would any engineer chance the accountants wrath by over designing any NA engine to tolerate over pressure from boost for long - a pure waste of money proving the engineer is unfit to keep his job.
The cheapest parts that will do the job [make it thru warranty and 100k which ever is sooner] is what mass production is all about.
Computers have enabled maunfacturers to wring out all the waste of yore, where you overbuilt, as the easiest method of creating longevity.......this wasteful concept was dropped im the mid 90's designs which went into production in 2002.
Look back at the J30/300zx engine [castiron block] even in it's mild boosted form almost every internal component was different and strengthened.
Hopefully the engineers use every stock internal failure on the web as proof they did their job well and frugally! See boss another one bit the dust see how good I am...........not a gram of extra weight in any of MY DESIGNS.
The cheapest parts that will do the job [make it thru warranty and 100k which ever is sooner] is what mass production is all about.
Computers have enabled maunfacturers to wring out all the waste of yore, where you overbuilt, as the easiest method of creating longevity.......this wasteful concept was dropped im the mid 90's designs which went into production in 2002.
Look back at the J30/300zx engine [castiron block] even in it's mild boosted form almost every internal component was different and strengthened.
Hopefully the engineers use every stock internal failure on the web as proof they did their job well and frugally! See boss another one bit the dust see how good I am...........not a gram of extra weight in any of MY DESIGNS.
12-07-2006, 07:34 AM
#17
Registered User
Join Date: Dec 2005
Location: Chicago Subs
Posts: 192
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by BriGuyMax
All that said, my stock motor is coming out of my car this weekend. It's still in perfect running condition..but I have bigger plans for the spring.
Niiice, good luck and can't wait to see what's up!
12-07-2006, 07:37 AM
#18
there's been many people who hurt their engine when the engine was NA
I think most of it is knowing what you're doing with maintenance. Maybe a small portion are faulty engines - if you're going to boost the stock block, usually it's a good idea to put a decent amount of miles on it first to make sure it's ok - and where warrenty can cover it if there was an issue
I think most of it is knowing what you're doing with maintenance. Maybe a small portion are faulty engines - if you're going to boost the stock block, usually it's a good idea to put a decent amount of miles on it first to make sure it's ok - and where warrenty can cover it if there was an issue
12-07-2006, 08:46 AM
#19
Registered User
iTrader: (18)
Join Date: Oct 2004
Location: .
Posts: 9,482
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by THE TECH
You'd think that Nissan's US flagship would at least have something that the Quest or Maxima doesn't have. Too bad Nissan doesn't care as much about the Z as they do the Skyline.
(note - the skyline is the g35)
12-07-2006, 08:55 AM
#20
Registered User
iTrader: (154)
Join Date: Jun 2003
Location: Hills of Anaheim
Posts: 10,735
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by taurran
The Z was designed to be profitable. The GTR is being designed to set the standard.
(note - the skyline is the g35)
(note - the skyline is the g35)