Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

fast intake install trouble

Thread Tools
 
Search this Thread
 
Old Sep 12, 2009 | 11:25 AM
  #1  
blue99fbody's Avatar
Thread Starter
10 Second Club
iTrader: (5)
 
Joined: Nov 2007
Posts: 1,052
Likes: 0
From: Cincinnati
Default fast intake install trouble

so i bought a used fast 90/90, in excelent shape. i ported it and put it all back together. i didnt get any instuctions with it or any extra bolts other than what was in the intake. so i put it on and as i start to tighten it i wasnt very tight at all on a back bolt and i heard something sound like it cracked. i decided to continue to put it on (stupid) and i got everything bolted up and started the car. its now idleing about 1100 and if you touch the gas it comes down to about 2100 and holds for like 5-10 seconds before it comes down. i then called my tuner to see if i prob cracked it or if it was maybe in the tune. he then told me i was supposed to change the valley cover bolts and that i mostlikely cracked it on the stock bolts. anyway my question is what bolts am i supposed to run in the valley and where to get them? and i havent pulled the intake back off yet but what is a good apoxy i can used to try to fix the intake and is it even possible?
thanks
Reply
Old Sep 12, 2009 | 11:41 AM
  #2  
02SOMWS6's Avatar
10 Second Club
iTrader: (6)
 
Joined: Nov 2003
Posts: 2,638
Likes: 2
From: Wallkill ,NY
Default

Originally Posted by blue99fbody
so i bought a used fast 90/90, in excelent shape. i ported it and put it all back together. i didnt get any instuctions with it or any extra bolts other than what was in the intake. so i put it on and as i start to tighten it i wasnt very tight at all on a back bolt and i heard something sound like it cracked. i decided to continue to put it on (stupid) and i got everything bolted up and started the car. its now idleing about 1100 and if you touch the gas it comes down to about 2100 and holds for like 5-10 seconds before it comes down. i then called my tuner to see if i prob cracked it or if it was maybe in the tune. he then told me i was supposed to change the valley cover bolts and that i mostlikely cracked it on the stock bolts. anyway my question is what bolts am i supposed to run in the valley and where to get them? and i havent pulled the intake back off yet but what is a good apoxy i can used to try to fix the intake and is it even possible?
thanks
the intake gets torqued down to inch lbs. not ft. lbs. That could be your first problem.The 90mm fast should be fine with the stock valley cover bolts. It's the 92mm that need sthe different valley cover bolts cause it sits lower than the 90mm. My 90mm fast was fine with the stock valley bolts and has been on and off the car at least 4 times with no issues
Reply
Old Sep 12, 2009 | 01:35 PM
  #3  
405HP_Z06's Avatar
TECH Addict
iTrader: (11)
 
Joined: Jun 2003
Posts: 2,215
Likes: 19
From: Arlington, Tx
Default

The FAST 78, 90, and 92 all come with M8 x 1.25 x 30mm button head allen bolts to replace the stock valley cover bolts. You can get these bolts at most hardware stores. According to the FAST instructions, the bolts must be changed to prevent manifold damage. I've seen this time and time again.....
Reply
Old Sep 12, 2009 | 01:55 PM
  #4  
NSSANE02's Avatar
11 Second Club
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (14)
 
Joined: Mar 2008
Posts: 1,434
Likes: 0
From: Houston
Default

Originally Posted by 02SOMWS6
The 90mm fast should be fine with the stock valley cover bolts. It's the 92mm that need sthe different valley cover bolts cause it sits lower than the 90mm. My 90mm fast was fine with the stock valley bolts and has been on and off the car at least 4 times with no issues
It's not just the 92, all of them should be used with the shorter bolts. The first time i installed mine (90) I cracked it in a couple places, luckily they were only small cracks on the outside and it didn't crack all the way through so no leaks.
Reply
Old Sep 12, 2009 | 01:59 PM
  #5  
02SOMWS6's Avatar
10 Second Club
iTrader: (6)
 
Joined: Nov 2003
Posts: 2,638
Likes: 2
From: Wallkill ,NY
Default

Originally Posted by 405HP_Z06
The FAST 78, 90, and 92 all come with M8 x 1.25 x 30mm button head allen bolts to replace the stock valley cover bolts. You can get these bolts at most hardware stores. According to the FAST instructions, the bolts must be changed to prevent manifold damage. I've seen this time and time again.....
maybe they come with the other bolts now but when the 90mm first came out they didn't come with it. Thanks for the heads up guys
Reply
Old Sep 12, 2009 | 01:59 PM
  #6  
02SOMWS6's Avatar
10 Second Club
iTrader: (6)
 
Joined: Nov 2003
Posts: 2,638
Likes: 2
From: Wallkill ,NY
Default

Originally Posted by blue99fbody
so i bought a used fast 90/90, in excelent shape. i ported it and put it all back together. i didnt get any instuctions with it or any extra bolts other than what was in the intake. so i put it on and as i start to tighten it i wasnt very tight at all on a back bolt and i heard something sound like it cracked. i decided to continue to put it on (stupid) and i got everything bolted up and started the car. its now idleing about 1100 and if you touch the gas it comes down to about 2100 and holds for like 5-10 seconds before it comes down. i then called my tuner to see if i prob cracked it or if it was maybe in the tune. he then told me i was supposed to change the valley cover bolts and that i mostlikely cracked it on the stock bolts. anyway my question is what bolts am i supposed to run in the valley and where to get them? and i havent pulled the intake back off yet but what is a good apoxy i can used to try to fix the intake and is it even possible?
thanks
try some JB weld
Reply
Old Sep 12, 2009 | 02:01 PM
  #7  
405HP_Z06's Avatar
TECH Addict
iTrader: (11)
 
Joined: Jun 2003
Posts: 2,215
Likes: 19
From: Arlington, Tx
Default

Originally Posted by 02SOMWS6
maybe they come with the other bolts now but when the 90mm first came out they didn't come with it. Thanks for the heads up guys
Your correct. At the very beginning some of the 90's didn't come with the required valley cover bolts.
Reply
Old Sep 12, 2009 | 02:31 PM
  #8  
blue99fbody's Avatar
Thread Starter
10 Second Club
iTrader: (5)
 
Joined: Nov 2007
Posts: 1,052
Likes: 0
From: Cincinnati
Default

Ok I just got the intake off there are indentions from the bolt heads and two stress cracks that don't look like they are all the way through maybe the bolts were just preventing the gaskets from a good seal. Anyway can I just grind off about half the head of the stock valley bolts or do I have to change them? Thanks guys
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old Sep 12, 2009 | 02:43 PM
  #9  
NSSANE02's Avatar
11 Second Club
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (14)
 
Joined: Mar 2008
Posts: 1,434
Likes: 0
From: Houston
Default

Make sure you look inside the intake and make sure it didn't crack all the way through. As for the bolts I would just replace them, but I'm sure a little grinding would work just fine.
Reply
Old Sep 12, 2009 | 02:52 PM
  #10  
405HP_Z06's Avatar
TECH Addict
iTrader: (11)
 
Joined: Jun 2003
Posts: 2,215
Likes: 19
From: Arlington, Tx
Default

Originally Posted by blue99fbody
Ok I just got the intake off there are indentions from the bolt heads and two stress cracks that don't look like they are all the way through maybe the bolts were just preventing the gaskets from a good seal. Anyway can I just grind off about half the head of the stock valley bolts or do I have to change them? Thanks guys
Replace, FYI, this is what a button head allen bolt looks like. Look for M8 x 1.25 x 30mm

Reply
Old Sep 12, 2009 | 03:20 PM
  #11  
blue99fbody's Avatar
Thread Starter
10 Second Club
iTrader: (5)
 
Joined: Nov 2007
Posts: 1,052
Likes: 0
From: Cincinnati
Default

Also one of the philips head screws on the bottom has oilly gas running from it so could my leak be comming from there
Reply
Old Sep 12, 2009 | 04:18 PM
  #12  
02SOMWS6's Avatar
10 Second Club
iTrader: (6)
 
Joined: Nov 2003
Posts: 2,638
Likes: 2
From: Wallkill ,NY
Default

my 90mm just happens to be off the car. I went and checked it out and there are no cracks but you can see where the valley bolts where touching. I'll be changing them before it goes back on the car. Last outing the car went 10.5 @ 130 so I know there are no cracks but it does seems messed up that Fast sold a bunch with out the valley bolts in the begining and if you didn't call with a issue then they didin't tell you. Glad I found out now. I had my 90mm Fast ported by Tony Mamo. Do you know how pissed I would have been if I cracked the bottom half and had to have the port work done over.For once luck was on my side.
Reply
Old Sep 12, 2009 | 04:34 PM
  #13  
NSSANE02's Avatar
11 Second Club
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (14)
 
Joined: Mar 2008
Posts: 1,434
Likes: 0
From: Houston
Default

Originally Posted by 02SOMWS6
seems messed up that Fast sold a bunch with out the valley bolts in the begining and if you didn't call with a issue then they didin't tell you.
It's messed up they keep selling stupidly expensive throttle bodys that stick constantly too, but they dont seem to care
Reply
Old Sep 12, 2009 | 05:05 PM
  #14  
405HP_Z06's Avatar
TECH Addict
iTrader: (11)
 
Joined: Jun 2003
Posts: 2,215
Likes: 19
From: Arlington, Tx
Default

Originally Posted by NSSANE02
It's messed up they keep selling stupidly expensive throttle bodys that stick constantly too, but they dont seem to care
Reply
Old Sep 12, 2009 | 05:27 PM
  #15  
Zaxz28's Avatar
TECH Apprentice
 
Joined: Oct 2008
Posts: 344
Likes: 0
Default

why should they care, they have a monopoly, we can't go anywhere else for a product like theirs.
Reply
Old Jan 11, 2010 | 09:54 PM
  #16  
InsaneDomestics's Avatar
TECH Enthusiast
iTrader: (28)
 
Joined: Feb 2009
Posts: 685
Likes: 1
From: Oklahoma
Default

I'm Having Another Problem. I Was At A Friends Helping Him Put On His FAST 90/90 And We Couldn't Get It To Sit Down And Seal All The Way... It Looked Like It Was Hitting The Front Of The Metal Cooling Line That Runs On Top Of The Valley Cover. Anyone Else Have Any Other Issues Other Than The Bolts?
Reply
Old Jan 11, 2010 | 10:42 PM
  #17  
InsaneDomestics's Avatar
TECH Enthusiast
iTrader: (28)
 
Joined: Feb 2009
Posts: 685
Likes: 1
From: Oklahoma
Default

Also, On The Hoses That Go From Your Intake To The Valve Covers, I've Seen Some With And Without Them. How Much Impotance Do These Have And What Is Necessary To Take Them Off? I Also Noticed That The Coolant Line Coming From The Radiator Doesn't Have A Spot To Connect To The 90/90, Can I Cap That Off Or Where Does It Need To Go?
Reply
Old Jan 12, 2010 | 05:43 AM
  #18  
fjb78's Avatar
Staging Lane
iTrader: (3)
 
Joined: Nov 2009
Posts: 61
Likes: 0
Default

You can grind down the stock bolts and it will work.
Reply




All times are GMT -5. The time now is 05:01 PM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE