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I've seen this question come up repeatedly and just wanted to teach a little one post lesson.

Installing an intake manifold is very simple as far as the level of complication involved in general mechanics. However there are some "Do's and Don'ts" that every professional auto tech follows, mostly because they have had to redo a job in the past, maybe several of them.

Here's some tips;

First off DON'T use silicone RTV around the intake port seals. If you want a demonstration of why, squeeze out a blob on something and let it cure for a couple of days and then drop it into a cup of gasoline. After a little while is will swell up and eventually dissolve away to nothing. That's not to mention that it will squeeze out into the intake ports and create a "blockage ring" that will severely compromise flow. THEN it will dissolve as the gas/air mix washes over it when the engine is running, and this stuff all goes right on through the engine. You can use the silicone ring gaskets because the ring is back away from the edge of the port and the gasket itself is what comes in contact with the fuel mix. The ring is a second line of defense and these gaskets work very well. The ONLY sealer product that will not dissolve in gasoline is Permatex Aircraft grade sealer and that is what almost all professionals use.

CLEAN the head surfaces, the end seal surfaces, and the sealing surfaces of the manifold with some type of solvent that dries completely. I use alcohol or brake cleaner. The main point is that there is no oil left on the surfaces - sealer wont seal to oil.

So, with a standard intake gasket wipe silicone on around the water ports on the end of each head SPARINGLY with your finger, and drag a little line out to the end seal area. Then squeeze a large line of silicone (at least a 1/4") across each end seal boss on the block. Don't bother even pulling the cork or rubber end seals out of the package. Those are a throwback to the days before good quality automotive silicone and won't do you a lick of good today.

USE guide studs in the 4 corner bolts - one on the end of each head. You can make these easily by buying long bolts and cutting off the heads and grinding these off smooth and rounded. Screw them in finger tight.

Lay the intake gaskets on the gasket card with the "This side up" down. Brush a fairly healthy layer of Permatex Aircraft sealer around each intake port ring. Then set each seal down over the guide studs on the heads ("This side up" up) and seat the lower corners down even into the silicone on the end seals.

Brush another fairly healthy coat of Permatex Aircraft sealer around the ports on the intake manifold, and then LIGHTLY spread silicone around the water passages on each end of both sides and do a small wipe over to the end seal corners, (Remember to do the front and back on both sides - even though there is no passages on the rear, it still needs to be sealed).

Then just set the manifold down over the guide studs. On many engines the intake bolts need to be sealed, if only so oil won't climb the bolts and leak out under the bolt heads. I use the Pematex as it gives a good torque value and does not harden so you can retorque later without a problem. Use a very small dab on the threads, it doesn't take much.

Drop all the bolts into the unused holes and starting in 2 opposing holes (one on each side) of the middle holes - tighten these center bolts "2 finger tight". (That means holding the ratchet close to the head between your thumb and first finger). Then progressively do the rest like that. Now remove the guide studs and do those four. Now do all the bolts "2 finger tight " again, they will all be loose again at this point.

Almost done. Now torque the intake using the factory pattern and spec, and then do it again and again until no bolts pull up when you draw the torque. Let it sit for about 1 hour and do it again one more time.

OK, now walk away until tomorrow and torque it again. You're done. I've been using this procedure for many years and never have a leak, or sealing problem on the ports.

Sorry for the long post, I hope it helps somebody from having to redo the job.
 

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Good advice /forums/images/icons/smile.gif! (although, now the phrase "2 finger tight" takes on a whole new meaning . . .) /forums/images/icons/tongue.gif!!

/forums/images/icons/laugh.gif/forums/images/icons/laugh.gif/forums/images/icons/laugh.gif (sorry ladies)

Rick
 

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Couldn't have said it better and I would advise anyone to follow those directions exactly.People still ask me what "that sealer is",and apparently never seen or heard of aviation cement.It's available at any NAPA store and I've used it for thirty years.One more great thing about aviation cement is that it stays put when it dries.You never have to worry about it beaking loose and stopping up a radiator or oil pump screen...
 

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Thanks Hal. Excellent post. I did my first intake with the help of Billgear a month ago. Followed Bills guidance and Tom Monroe's excellent book, How to Rebuild Small Block Fords.

No leaks.

The only thing I didn't do from your post was use aircraft sealer around the intake ports. I did however use one of FelPro's race gaskets with the blue stuff around each intake port... I guess that's the same thing.

Thanks for the post!
 

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Hal,

I've never done this but I will need to sometime in the near future. Thanks.

One thing I recall seeing a few times in old posts is that you should omit the cork end seals:

Look here

Any comment on doing that?
 

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Thanks for the tips Hal...

I don't use RTVS much so I'll remember the one about the aviation sealant...

As I've come across an addtional issue more than once on the VMF, when folks are assembling a new engine, make sure to check, when installing the intake, especially on a W, that the oil transfer passage soft plug at the top rear of the valley has been installed. The intake hides it once installed...

I've heard, when not installed, that the intake is well lubricated but the oil pressure sucks...*G*

Got any more tutorials up your sleeve?? *G*

If you'd like, I can post them, with the appropriate credit, on my web site....
 

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Discussion Starter #10
hehe, I remember that post about the transfer soft plug missing. I can imagine what would have happened if the engine would have been cranked with the manifold off. It sure would have oiled the heck out of the car parked on the left of it......... *G*.

Sure, you can post this on your site if you like. I was thinking of doing a series of these. I just haven't decided what would be usefull and not just common knowlege. It's hard to remember on a day-to-day basis that we had to learn this stuff, you know what I mean for sure.
 
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Hal,

Thanks for the excellent advise. Fortunately through dumb luck I used the same materials when I overhauled my coupe, except I only torqued the manifold twice, and ran the engine just long enough to tune and tweek. I now have the entire car in pieces while I restore the rest of it. That was about 2 months ago. Is it too late to re-torque the bolts? If not how do I proceed? Run the engine again and warm it up?

Thanks

Dave
 

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That's almost exactly how I did it. I didn't use guide studs, as I lifted the manifold (Edelbrock performer) without the carb. Pretty light. It's just a long reach back to the setpoint for the manifold.

A series of this is a great idea.
 

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Hal,

your post brings up, once again, the need for an archive of EXACTLY what you just explained - the correct way(s) to do certain functions that many of us old timers simply take for granted. I am not sure how this could be accomplished and understand that it would be quite an undertaking. Too many times we read the same questions, valid as they may be, on how to install a T5, or an export brace, engine/tranny combo, Granada disc brake changever, etc, etc, etc.

I guess what is needed is some kind of coming together of the vintage minds (ie old farts) here at the forum to begin to think of the most effective way of compiling this type of information into a layman's understandable tool. Hell, the thing could have pics and be offered on CD as a "tool" to be kept in the ol' toolbox next to the torque wrench and 1/2 inch wrench. I am willing to offer my input, however, dont really know the nutz and bolts of "computerizing" something like this. Suggestions???

randy
 

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Well guys, I'm anxious to get some of this Permatex Aircraft cement. But I searched the Permatex site with no luck. If someone could post a part# and/or source, I would greatly appreciate it.

I do have a Napa store nearby, but if I go in there without a part number, I'm p***ing in the wind. The guys in this store are dumber than a bag of hammers! *G*
 

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Discussion Starter #18
I think that's a great idea Randy. I think the first step would be to put the tech together (over time) and get it stored in the same place. Pat said he had space for some of that also. We need to challange the OF's (yes, I'm included) to write something like one every week. I know I work better myself with a challange at hand then an "I need to do that someday"......... *G*.
 
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