Problems, problems, problems......
Le Mans Master
Joined: Feb 2000
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From: Kempner Texas
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!
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Safety Car
Joined: Dec 2007
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From: Sandhills of North Carolina
Here is what I borrowed from someone else in regards to the "holes" in the bottom of the manifold. This is a modification done when the manifold is ported to ensure proper BLM's/Idle etc as it is a manufacturing problem. This came from a very highly respected head porter.
""Also, another thing that's worth mentioning that some still don't know about.... "IF" your interested in getting the nicest possible idle out of a cammed LT-X set-up (if you haven't done it already).......Next time you have the LT intake manifold off the car.....flip it over, and remove the bottom (metal cover with the 4 bolts)......then remove ALL of the large Allen type pipe plugs that are under it......By removing the large pipe plugs, you'll gain access to the individual IAC port holes that go out to "each" manifold runner (there are two under "each" plug)..........From the factory, these holes are not perfectly even (size wise) from hole to hole like they should be.....And (very commonly) one of them is usually REALLY bad (small)......Many of them also have thick aluminum burrs partially blocking the passages due to a sloppy factory drill job......Take your largest hole out of the bunch (verified by sliding drill bits in them), then once you get the drill bit for the largest one....Drill the rest out to match.....Then RE-install your pipe plugs with some permatex #2 (the non-hardening sealant), and ofcourse loc-tite your metal splash cover back on.........This process also made a noticeable difference on mine, and is something that I always do on ALL of the LT-X engine's that I do Heads & Cam packages on.......The end-result is Not as drastic as the IAC hole being sized properly, but it's a nice difference none the less."
""Also, another thing that's worth mentioning that some still don't know about.... "IF" your interested in getting the nicest possible idle out of a cammed LT-X set-up (if you haven't done it already).......Next time you have the LT intake manifold off the car.....flip it over, and remove the bottom (metal cover with the 4 bolts)......then remove ALL of the large Allen type pipe plugs that are under it......By removing the large pipe plugs, you'll gain access to the individual IAC port holes that go out to "each" manifold runner (there are two under "each" plug)..........From the factory, these holes are not perfectly even (size wise) from hole to hole like they should be.....And (very commonly) one of them is usually REALLY bad (small)......Many of them also have thick aluminum burrs partially blocking the passages due to a sloppy factory drill job......Take your largest hole out of the bunch (verified by sliding drill bits in them), then once you get the drill bit for the largest one....Drill the rest out to match.....Then RE-install your pipe plugs with some permatex #2 (the non-hardening sealant), and ofcourse loc-tite your metal splash cover back on.........This process also made a noticeable difference on mine, and is something that I always do on ALL of the LT-X engine's that I do Heads & Cam packages on.......The end-result is Not as drastic as the IAC hole being sized properly, but it's a nice difference none the less."
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Mike, I sent you a PM with the Intake Install information. Here's a photo of mine when I was building my 388. Best one I have.
If you look closely at the rear China Wall you should be able to see the dimples.
Oh, and feel free to share the doc file with others.
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!! ARMY Vs NAVY TODAY!!!!!
If you look closely at the rear China Wall you should be able to see the dimples.
Oh, and feel free to share the doc file with others.
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!! ARMY Vs NAVY TODAY!!!!!
Le Mans Master
Joined: Feb 1999
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From: South Carolina
St. Jude Donor '03 & '05
I always use Permatex "The Right Stuff" Gm developed this with permatex to rid their engines, LTx type, of manifold leaks in the rear. Never leaks, even under boosted engines.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
Likes: 5
From: Sandhills of North Carolina
Mike, I sent you a PM with the Intake Install information. Here's a photo of mine when I was building my 388. Best one I have.
If you look closely at the rear China Wall you should be able to see the dimples.
Oh, and feel free to share the doc file with others.
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!! ARMY Vs NAVY TODAY!!!!!
If you look closely at the rear China Wall you should be able to see the dimples.
Oh, and feel free to share the doc file with others.
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!! ARMY Vs NAVY TODAY!!!!!
Thanks Jake, that's a great write up!
As I had mentioned in my PM I didn't have any leaks. I guess that's because I did it about the same as your write up except for the rough sanding of the heads and intake surfaces. I also used the right stuff to seal the china walls. Let me tell you though, that stuff doesn't come out of those dimples very easily at all. I took lacquer thinner and dissolved it the best I could to get most of it out.
Everything I can do is done. Lifters are out, guide plates are off, intake is cleaned up and I did drill out that small hole in the intake as Steve had pointed out in his post above. I also ran the bit down through the rest just to make sure they all were the same size. So I'm waiting on parts. No telling when they'll get here with the time of year and all. I'll continue when they do get here.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Must be why I've always had such good results from RTV. Removing the residual RTV from the dimples was easy for me. I figure it's the Right Stuff that caused your removal problem.
The friction resulting from sanding/dimpling increases RTV adhesion. Think about how easily your hand will slide across a sheet of glass as compared to a sheet of 40 grit sand paper.
I once bought a can of Right Stuff, didn't like it, so I threw it under my work bench and haven't bothered to look for it since. No need to re-invent the wheel was my thinking on that. Had I had a problem with the RTV, I would have used something else, but since I didn't, I didn't.
Waiting on parts isn't all bad; you probably need that break anyway.
Hang in there and MERRY CHRISTMAS!
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!! Army Vs Navy Today!!! - Doesn't Look Good :-(
The friction resulting from sanding/dimpling increases RTV adhesion. Think about how easily your hand will slide across a sheet of glass as compared to a sheet of 40 grit sand paper.
I once bought a can of Right Stuff, didn't like it, so I threw it under my work bench and haven't bothered to look for it since. No need to re-invent the wheel was my thinking on that. Had I had a problem with the RTV, I would have used something else, but since I didn't, I didn't.
Waiting on parts isn't all bad; you probably need that break anyway.
Hang in there and MERRY CHRISTMAS!
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!! Army Vs Navy Today!!! - Doesn't Look Good :-(
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From: Southside of Western Norte Americano State of Confusion, ColoFornia
St. Jude '13
Ok I finally have to ask.. " the great wall" you mention.. the front and rear of the block casting that meets the manifold ? Going between the heads? (the place where all the 1st gen SBC's leaked until we got RTV ?)
Just had to ask.. thanks
Just had to ask.. thanks
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Thread Starter
Safety Car
Joined: Dec 2007
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From: Sandhills of North Carolina
This is a better picture of what Jake is referring to about dimpling.
Last edited by Weav's Vet; Dec 22, 2013 at 01:22 PM.
Burning Brakes
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From: Minneapolis MN
Race Director
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From: Slidell Louisiana
The Right Stuff is the Right Stuff!
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
LOL! Never fails. Seems that no matter what gets posted there's always someone who'll disagree and is absolutely convinced that "his way" is the better way. Then, to support that position, cites the trillions of miles of use with no problem. Brings a smile to my face each time I come across them.
Great living in America, isn't it!? Freedom of choice and all that. LOL
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
Great living in America, isn't it!? Freedom of choice and all that. LOL
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
Le Mans Master
Joined: Feb 1999
Posts: 9,916
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
LOL! Never fails. Seems that no matter what gets posted there's always someone who'll disagree and is absolutely convinced that "his way" is the better way. Then, to support that position, cites the trillions of miles of use with no problem. Brings a smile to my face each time I come across them.
Great living in America, isn't it!? Freedom of choice and all that. LOL
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
Great living in America, isn't it!? Freedom of choice and all that. LOL
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
I support/use the Right stuff because it works very well, on all engine areas needing RTV. Being GM developed it with their R&D after having LT1 manifolds leaking issues, as well as L98 (back cylinders due to heat on manifold to head), I say it probably has a few miles to account for being a good product.
Yes, there are many fine products out there for sealing things. But, Mike needs opinions and peoples actual real life experiences to go forward.
Thread Starter
Safety Car
Joined: Dec 2007
Posts: 3,616
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From: Sandhills of North Carolina
I'm so afraid that after I have gone back and done all this work, again, I'm going to end up with the same problem at the end. I mean look at these dyno pulls. How can this be? How can a cam that is supposed to add probably 35 or 40 rwhp end up this close to a stock motor with a stock PCM? It's drivin me nuts guys... I really do hope it's that opti or not having the LT4 module in there. If it's not I guess I'll just put it back to stock and call it a day. Just wasn't meant to be......
Race Director
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From: O'Fallon Missouri
If the changes you are making doesn't solve your problem, and I'm thinking the opti will be the only real change. Then the next step is to do some data logging, which should have been done after the initial dyno session.
Thread Starter
Safety Car
Joined: Dec 2007
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From: Sandhills of North Carolina
I understand that and it was done I just don't have the results and they weren't saved. The guy at RPM Motorsports did it when he made the pulls. All he said was that one side of the motor was acting differently than the other. He had no explanation as to why.
Le Mans Master
Joined: Feb 1999
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From: South Carolina
St. Jude Donor '03 & '05
Well, while waiting for parts etc, look at fuses, wires, connectors etc etc. just for a quick check prior to restarting it. Cant hurt.
Le Mans Master
Joined: Feb 2000
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From: Kempner Texas
Jake, Its good to have professional opinions here too.
I support/use the Right stuff because it works very well, on all engine areas needing RTV. Being GM developed it with their R&D after having LT1 manifolds leaking issues, as well as L98 (back cylinders due to heat on manifold to head), I say it probably has a few miles to account for being a good product.
Yes, there are many fine products out there for sealing things. But, Mike needs opinions and peoples actual real life experiences to go forward.
I support/use the Right stuff because it works very well, on all engine areas needing RTV. Being GM developed it with their R&D after having LT1 manifolds leaking issues, as well as L98 (back cylinders due to heat on manifold to head), I say it probably has a few miles to account for being a good product.
Yes, there are many fine products out there for sealing things. But, Mike needs opinions and peoples actual real life experiences to go forward.
I wasn't referring to you, or your Right Stuff preference, Steve.
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
Race Director
Joined: Jan 2002
Posts: 12,261
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From: O'Fallon Missouri
There is also a possibility the valves weren't adjusted correctly before.
I feel for you Weav, you have been through the ringer fiquring out this problem. I've always been nervous to restart my car after engine mods, but I've been fortunate that everything somehow seems to work out.
I feel for you Weav, you have been through the ringer fiquring out this problem. I've always been nervous to restart my car after engine mods, but I've been fortunate that everything somehow seems to work out.
Last edited by STL94LT1; Dec 13, 2009 at 07:17 PM.
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
LOL! Never fails. Seems that no matter what gets posted there's always someone who'll disagree and is absolutely convinced that "his way" is the better way. Then, to support that position, cites the trillions of miles of use with no problem. Brings a smile to my face each time I come across them.
Great living in America, isn't it!? Freedom of choice and all that. LOL
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
Great living in America, isn't it!? Freedom of choice and all that. LOL
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!
