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Discussion Starter #1
Just received all new Ford parts to do the PI intake swap on my 97' 4.6L. My engine now has 147,000 mi's, I bought it with 97,000. I've been thru almost every mod short of switching to a PI motor. Two steps up and one step back. But that is how the game is played. Ching Ching. Even though I do read all the info on this site before I do a mod, I never realized when doing the PI intake swap, some guys use the NPI gaskets and RTV all 8 of the intake ports /vs/ using PI gaskets and sealing just the water flow situations at the pass. front and the drivers back. I'm going to use the PI gaskets. As of right now my car runs and looks TITS. I bounced around the idea of doing PI heads too, or maybe just the cam, but it's just not worth it with an old bottom end. If you're going to do it up, do it up right or not at all. That's the school I'm from. And I will not break that front cover off unless the whole engine comes out. So, intake it is. Let the good air in and the bad air out. That's the game being played. ED
 

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i guess most people would rather RTV the ports considering how little the stress on the RTV would be from vacuum being produced when air is sucked from the intake ruuners, as opposed to the water pressure that would be exerted on the RTV sealing the coolant passage.....i myself do not know the magnitude of the pressure the RTV would experience at the coolant passage junction, but i feel safer with less-stressed RTV at the intake runner/gasket junction .......thats my take on it
 

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I have used both. I am running PI gaskets on mine because I liked the setup better. I believe JL is running PI gaskets on his and I know there are a lot of others. I thought the PI gaskets with RTV around the water ports might leak too. That was only up until I realized I was being an idiot about it.
It will work either way you go if you do it properly.
Just FYI, there have been a lot of people with leaks with the NPI gasket setup, so either way you go you run that risk if it isn't done correctly. But it is worth it in my opinion.
 

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I've used NPI gaskets on both PI swaps I've done, and neither one had any problems at all.
 

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MadRussian said:
Use the NPI gaskets, the RTV is not a solution to the water passages as it WILL leak.

-Andrey
:bs:
If that were the case,then EVERY engine that was built from the early 50's thru the mid 80's would have leaked-ALL of them were sealed with an RTV bead at some point on the intake manifold.
And yes-I'm using PI gaskets with RTV on the coolant ports,and the engine sees right at 7K rpms on the 1-2 shift.No problems,no issues with leakage.
JL
 

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Discussion Starter #7
Guitar Maestro's PSI theory got me thinking. Our water pumps do about 18 PSI tops. The vacuum PSI @ idle, I'm guessing is also about 16 PSI. Never really put a gauge on a newer car, but I think that's close. Given a hole of minute porportion and increasing the size of the hole until a fluid or air could ecsape, air is going going to slip through the hole first, and at a faster rate because the viscosity of air should be 0 or 1. It's been a while since I've been to the school of how it really is. The viscosity of anti- freeze is greater than air. Now with the PI gasket, the air intake holes are sealed 100%. That's good, because if it leaks at the anti-freeze port it will not go into the air chamber. The prob is isolated. In the old days, you could use form a gasket @ the water pump to housing seal, instead of a gasket. Granted the heat on top of the head is more, but the PSI is the same. May just need some more flexable, high heat, non-harding form a gasket on that water situation. Hi- heat RTV silicone base may not be in the cards. Something that bonds to old aluminum and plastic at the same time, and can still stay flexable under extreme conditions. Then it's just a matter of a little dab will do ya. The right material to seal that potential water leak is in question. I'll research that end of it. I'm only gonna do this once, the materials used need to be defined.
 

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Permatex Ultra Black
Done.
JL
 

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Discussion Starter #9
JL, I believe we are nailing the PI swap situation down to a tack head. It takes time and money to take the intake off and replace it with something that is not a 100% direct swap. Even though it is just a matter of what material is gonna hold that anti-freeze back for ten years, it needs to be defined. PI intake gaskets are the path, the two potential water leaks are the situation, the right material for the seal is the solution.
 

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Well, here's the reason I said what I did:

I did my PI intake swap just when it was beginning to get popular, probably one of the first few (after JL of course)

Anyhow, I just did a headswap, and this is the first time the PI intake came off since it was installed. I used a NPI gasket, and used Permatex black RTV. The RTV on the intake when I took it off was not in the same state as when I put it in - the gasoline vapors most likely affected it, and it was very soft and mushy to the touch (still in place though)

Now, I dont know if coolant will have a similar effect on permatex black, but I have a strong feeling that it will eventually leak. It may be more than a year - true, and that is probably acceptable for people who dont keep an intake on for that long.

Another issue is that a small seepage of coolant would not be noticeable from a drivability standpoint, so unless you have had the intake for several months and taken it off to inspect I wouldnt say its a permanent solution.

Anyhow, not saying that PI gaskets should be ruled out, as both have certain "downsides".

-Andrey
 

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MadRussian said:
Well, here's the reason I said what I did:

I did my PI intake swap just when it was beginning to get popular, probably one of the first few (after JL of course)

Anyhow, I just did a headswap, and this is the first time the PI intake came off since it was installed. I used a NPI gasket, and used Permatex black RTV. The RTV on the intake when I took it off was not in the same state as when I put it in - the gasoline vapors most likely affected it, and it was very soft and mushy to the touch (still in place though)

Now, I dont know if coolant will have a similar effect on permatex black, but I have a strong feeling that it will eventually leak. It may be more than a year - true, and that is probably acceptable for people who dont keep an intake on for that long.

Another issue is that a small seepage of coolant would not be noticeable from a drivability standpoint, so unless you have had the intake for several months and taken it off to inspect I wouldnt say its a permanent solution.

Anyhow, not saying that PI gaskets should be ruled out, as both have certain "downsides".

-Andrey
Permatex black is not rated for contact with oil or gasoline-that's why it broke down on the intake ports,and is another reason not to use RTV there.Permatex Ultra Black is rated for contact with oil,antifreeze,(but not gasoline)and will not break down over time on the coolant ports-it's made for sealing oil pans,water pumps,etc.
JL
 

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I just did my PI intake swap(3weeks ago & 1200 miles so far NO problems)...I used the NPI gaskets and used red High temp RTV. I would not ever use rtv around any coolant areas. uless it could be compressed ALOT....as it will not hold the heat and pressure of todays cars.I have lots of pictures if you want them email me.. [email protected]
 

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I used the Ultra Copper on mine, but I didn't really think it was necessary since I matched the ports like kdanner did. The second one I did I used no RTV at all, and it too has had 0 problems. That one was done mid summer, and mine was done back in March.
 

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I did the swap last week with NPI gaskets and ultra black. last night it started stumbling and sputtering. I took the manifold off today thinking I messd something up and the ports looked ok so I bought some PI gaskets and som Hi temp red silicone (right stuff-yes-no?) and re did it all. I dont know if it was caused by the intake installation but it never threw any cel's so I'm hoping this fixes it.

Any ideas on what would cause stumble, sputter, backfire all of a sudden?

Thanks,
-Dave
 

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91bluecoupe said:
as it will not hold the heat and pressure of todays cars.
What is so hard to understand?
An internal combustion engine is an internal combustion engine.
The cooling systems are operating at the same pressure today as they were 20 years ago.
Sounds like the majority of the people that drive cars today are idiots that believe the Castrol commercials that claim todays engines are SO different than the engine that were built years ago.
The only differences are the different fuel and spark management systems...THAT'S IT!.
JL
 

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davesxx01 said:
I did the swap last week with NPI gaskets and ultra black. last night it started stumbling and sputtering. I took the manifold off today thinking I messd something up and the ports looked ok so I bought some PI gaskets and som Hi temp red silicone (right stuff-yes-no?) and re did it all. I dont know if it was caused by the intake installation but it never threw any cel's so I'm hoping this fixes it.

Any ideas on what would cause stumble, sputter, backfire all of a sudden?

Thanks,
-Dave
i used the Permatex red hi-temp gasket-maker RTV on my PI intake and didnt have a single problem

maybe a vacuum line came off or something....i know i busted one up when i did the swap....after that, everythings been A-OK
 

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Well, after swaping everything over again,(I'm a pro now)! and still having the studdering I contacted a friend at the local Stealership and after two more hours of testing we found a hole in the #1 spark plug wire causing a short that also took out the coil. I read a post earlier about someone else having the same problem but never thought it could be the same problem as mine,,,,:( I guess I learned to listen to you all more often as there was nothing wrong with my intake install after all.

Thanks all,
-Dave
 

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Discussion Starter #19
Since JL mentioned the Permatex ultra-black, I stopped at a Pep Boy's to pick some up and they had one of those hard plastic cards on a chain with all the different Permatex types and situation uses. Since the anti-freeze situation associated with high heat was my only concern, the ultra-black silicone is the stuff to use, because with the PI gasket, the intake ports are 100% sealed. Fuel and air should not be an issue. But with silcone, the mating surfaces need to be perfectly clean. So after removing the old intake and cleaning the surfaces, I'm going to use lacquer thinner to clean the mating surfaces. This should allow the silicone to bond to both plastic and aluminum. I also read Davesxxo1 spark grounding situation after the PI intake install. That was good to read because I know from experience that parts get old and develop a set, and work good untill you disturb them. I always try to replace everything that's more than 2 years old if it's taken off. When I do this swap, the old water pump, sepentine belt, tensioner, pulley, thermostat, upper and lower radiator hoses, anti-freeze, temp sensors, will be canned for sure. I am also thinking of replacing the 150,000 mi. injectors with a matched set of 19lbs, just so when I'm done getting under the hood, the probematic situations are history.
 
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