RTV PI Question(s) for you

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
1. American Muscle suggest i use the PI intake gasket and put RTV on EVERY port. WTF? Here the quote from there guide
Now do not forget to put the silicone in each head or you might end up with a leak. You could try it without the silicone but it might not work, so be safe and use it.


2. Weather in chicago is getting down to the single digits very soon. Is RTV curing time effected by this or not?


3.Some guys say wait 2-4 hours for the RTV to cure while some say overnight. Is the 2-4 pretty much right meaning the overnight thing is just for extra precaution. I also read about guys firing it up right after they finished.

4. How long did you PERSONALLY wait to fire her up?
 
don't know about the cold temperatures but when i did the rebuild on my 93 cobra
i waited 24hr's just too be safe this was summer time in texas

i would put it in garage and wait 48hr but that's just me
 
1. Using PI gaskets, there is one spot on each head, at the water jacket. Front of the car on the passenger side, and rear of the car on the driver side, if I remember correctly. Somewhere on Stangnet there is a picture showing exactly where to put the RTV, but I cannot find the damn thing. When you lay the gasket onto the head, you will see EXACTLY where the RTV needs to go.

2. I do not know, although I did mine when it was cold outside. See next answer.

3. I finished mine up around 6 one afternoon, and waited until noon the next day to fire it up. Even then, I was easy on it until later that night. Overnight should be alright. No problems in a year and 15,000 miles.

4. About 18 hours.


Worst case scenario is that it leaks a little water, and you have to take it back apart and re-RTV it. And you'll see, it would be WAY easier the second time around. I could easily do a PI intake swap in less than 2 hours now, even though it took over 6 the first go round.

And if it hasn't been done lately, go ahead and change your spark plugs. They are MUCH easier to get to with the intake and fuel stuff out of the way. I didn't at first, and apparently some water got into a couple of them. Then I had to change them with the intake on. #3 and #4 were a complete PITA.
 
Here's one from AM. This is the passenger side. The driver's side looks just like it, except is on the rear of the head. As you can see, it really isn't much, and honestly, I don't think I've ever heard of anyone that used the PI gaskets and RTV having any trouble.

pi-install-image-17.jpg


Still can't find the one I'm looking for...
 
Honestly, I have never used any RTV on any modular engine except where the timing cover and head meet (as per the Ford service manual for a valve cover gasket repair/replace).

I have done 4 intake repairs/replacement without any leaks (always use new gaskets).

IMO the gaskets are very well designed and will give good service if installed correctly (torqued to spec and not over torqued).

The exception that comes to mind would be if an old gasket were to be reused. In that case, adding RTV might be a good idea.
 
The shape of the NPI water jackets is such that the PI gasket will miss in two spots, one on each head. The RTV is needed to create the seal, else you will leak coolant, but American Muscle is WRONG about needing RTV on each intake port. In total I used two pea-sized quantities of RTV for the whole installation. Always do a reality check before blindly following someone's advice, because sometimes it will turn out to be half-baked.
 
With stock replacement parts, yes, that would be correct. But this is putting a PI (mid 01-04) intake onto the NPI head, which aren't meant for each other.

As you can see in the picture, the PI gasket does not match up exactly with the NPI heads. It completely surrounds and seals all of the air ports, and obviously would match up exactly to the PI intake, but not the water jackets on the NPI head. This is why the RTV is needed, to help seal up the water jackets. The gasket just does overhang the lip of the jackets, and the amount of RTV needed to make it seal is quite small, just a dab really.

If you were to use the NPI gaskets (which most everyone would not recommend, lots more work), the gasket would match up to the head (and thus the water jackets) but not the air ports on the PI intake, and therefore RTV would be needed on all 8 air ports.

In other words, we're kinda jerry riggin a PI intake onto an NPI head here. There are companies that make adapter plates for the PI intake/NPI head, but honestly, at $400 a pop, they're not worth it. The RTV jerry rig/trick has worked flawlessly for probably hundreds of people, myself included.

edit: StangGT97 beat me to it
 
I've said it on SN95forums and Ill say it here again lol, I did my PI intake swap in January and fired the car up right after I finished bolting everything up, so about 2.5 hours in 40deg weather and snow lol.

No problems at all...

I need to scan a diagram of where ther RTV needs to go that came with my eBay kit.
 
Honestly, I have never used any RTV on any modular engine except where the timing cover and head meet (as per the Ford service manual for a valve cover gasket repair/replace).

I have done 4 intake repairs/replacement without any leaks (always use new gaskets).

IMO the gaskets are very well designed and will give good service if installed correctly (torqued to spec and not over torqued).

The exception that comes to mind would be if an old gasket were to be reused. In that case, adding RTV might be a good idea.

You must use RTV or an adapter when putting a PI intake on a an NPI car.

Sneaky got it right on. You need to RTV the crap out of the water jackets. Make sure you clean the intake/heads so you get a tight seal.

Also, you need to rip off the little notches that come on the new PI gaskets. They don't fit in to the NPI heads and won't allow the gaskets to sit flush.
 
When you guys say torque it to 15-22. Does that mean pick any number between that and use it for all the manifold bolts? So i can pick 20?

I think I remember I torqued mine to 20. Don't forget, start in the center of the intake and work outwards, in a criss-cross manner. There's a tightening sequence somewhere, just search for it.

Also, you need to rip off the little notches that come on the new PI gaskets. They don't fit in to the NPI heads and won't allow the gaskets to sit flush.

Yup.

Also, read this. http://www.stangnet.com/mustang-for...l-pi-intake-swap-information.html#post7752209