[Old Pony]

OK… I’m sure I’ll get a lot of different opinions on this one, but here goes. I’m building a new engine (347), I’ve never built one from the ground up before so pardon the stupid question, but for the gaskets (not head, or manifold) do you NEED RTV with the gaskets or not? Seems to me the gaskets are made to seal, so you wouldn’t need anything. I’ve also heard builders use just RTV to make the gasket. OK, so I’ll call upon the experts… what’s your opinion guys (and gals)?
Thanks for any info… you all are always great!!

[mitchc]

In my opnion there are several good uses for RTV when building an engine. In the corners of the intake manifold is a good one. Also in the corners of hte oil pan. I use it to hold the intake gasket in place by putting a small bead around the water jackets on the head to manifold. I dont know how many gaskets I've seen leak there. RTV is not a bad thing. Just dont use a ton on everything, it will squeeez out and get into the engine. I also like to use it to glue the valve cover gasket to the valve cover that way you can take the cover off and not distory it plus the gasket will come off easy if you ever need to change it.

Originally Posted by Old Pony

OK… I’m sure I’ll get a lot of different opinions on this one, but here goes. I’m building a new engine (347), I’ve never built one from the ground up before so pardon the stupid question, but for the gaskets (not head, or manifold) do you NEED RTV with the gaskets or not? Seems to me the gaskets are made to seal, so you wouldn’t need anything. I’ve also heard builders use just RTV to make the gasket. OK, so I’ll call upon the experts… what’s your opinion guys (and gals)?
Thanks for any info… you all are always great!!

[oldbogie]

Originally Posted by Old Pony

OK? I?m sure I?ll get a lot of different opinions on this one, but here goes. I?m building a new engine (347), I?ve never built one from the ground up before so pardon the stupid question, but for the gaskets (not head, or manifold) do you NEED RTV with the gaskets or not? Seems to me the gaskets are made to seal, so you wouldn?t need anything. I?ve also heard builders use just RTV to make the gasket. OK, so I?ll call upon the experts? what?s your opinion guys (and gals)?
Thanks for any info? you all are always great!!

I think the best uses for RTV are sealing showers, tubs, and sinks. I don't feel the stuff has any application to things mechanical.

When you put a blob on and drop an intake into place, do you have any idea where the squeeze went? No you don't! That stuff cures to a solid and insoluble material and if that blob on the inside of the engine is loose, it circulates with the oil till it ends up in the pan. No thanks, that's something I can live without.

I use non hardening Permatex, it's the only sealer the FAA lets fly, that's a good endorsement for the stuff. Use it in the corners where gaskets join or to position gaskets as you're building. It should never take much sealer for anything, if it does then the part is in need of machining to make it square, parallel, and flat as it should be. Using an eighth inch of RTV, or Elephant Snot, or any-other sealer is not a good substitute for proper machining.

Engines that use one-piece intake manifold with a cast valley cover will always and eventually ooze oil, get used to it. Buy a can of Gunk and wash the thing now and again.

Bogie

[jimfulco]

Some gaskets will stick like stink if you don't use something on them, so if you think you might ever need to take it apart again, use something like the aforementioned non-hardening Permatex (#2 in a tube or #3 in a can).

RTV is also a pain to completely remove. I've used it for a couple of "engineering" jobs on my own cars when I didn't have time or access to the proper part, but I agree with Bogie. I see no real need for it in normal automotive work.

[345 desoto]

FWIW, when I disassembled the Mark VIII 4.6 I'm working on, it came from the Factory with black RTV in all the corners where 2 parts bolted together...heads to block, etc. And it's REALLY tough stuff...

[Old Pony]

Thanks guys!
I think I'll go with the Permatex... thanks again!

[ap72]

I've seen a lot of MOPAR parts that were sealed with only RTV from the factory.

There's a lot of stuff the FAA won't let fly, that doesn't mean it shouldn't though. Look at expieremental homebuilt aircraft to see all the things they won't let fly, and how well many of them perform.

[JeffB]

Since you are working on a Small block Ford I would disagree with the others,I would put a THIN layer around the water ports especially at the rear.Reason being since most SBF intakes are blocked off at the rear water passage and they tend to corrode,RTV does not corrode.If you ever look at used SBF intakes almost all of them have corrosion issues around the water ports,I would also recommend using Redlines Water Wetter to reduce the corrosive effects and always use distilled water in your cooling system mix, in many areas such as here in the southwest there is a high akalai content in tap water that destroys aluminum.Just as a side note,I saw a Fel-Pro valve cover gasket set for a Saturn : 10 plastic washers and 2 tubes of RTV, so go figure?

[Old Pony]

Anybody use Permatex's "The Right Stuff"... I've heard good things about it. Is it actually RTV? The web site dosen't really say.
I hate to dwell on the subject, but the engine I'm replacing leaks like crazy, and I got sick of patching it up... I DON'T want it to happen with the new one. As always, thanks for the info!!

[Old Pony]

Beautiful pictures by the way guys!!

[JeffB]

Originally Posted by Old Pony

Anybody use Permatex's "The Right Stuff"... I've heard good things about it. Is it actually RTV? The web site dosen't really say.
I hate to dwell on the subject, but the engine I'm replacing leaks like crazy, and I got sick of patching it up... I DON'T want it to happen with the new one. As always, thanks for the info!!

After I retired I delivered parts for Checker Auto's commercial accounts, the garages that used "The Right Stuff" swore by it and refused any substitutes,so it must be pretty good

[sbchevfreak]

The right stuff is the best gasket replacement sealant I have ever used. I dont believe it is actually an RTV silicone, though. You don't need much of it, either. Make sure that the surfaces are CLEAN AND DRY, and that stuff will never leak.

While I feel that silicone is used far too excessively by most, it does have its place. Properly used, it won't cause any harm, but not many take the time to do so. More is not better, and you have to giv RTV time to cure befor you a) bolt stuff together, and b) put it into service. 10 minutes minimum to allow it to "skin" over befor assembly, and minimum 6 hours befor putting it into service, preferrably 12 hours.

That is where the right stuff shines. It cures to a "return to service" state within 30 minutes, assembly state immediatly. I had a t-case on a customers 93 chev 4x4 that I had sealed with right stuff to the t-case adapter. When I went to remove the t-case a week later to do a clutch replacement, I removed all 6 bolts and hung off the tailshaft ectension. I'm 6'2", 250#, and it took 5-6 good bounces to get the sealant to let go. I have used it for several years, and when the surfaces are clean and dry, have never had it leak.

[Frisco]

Years ago I used only Permatex. Either the liquid brush on or the non-hardening stuff that comes in a tube.

More recently I have found that clear silicone RTV is superior to either of the Permatex products for some areas.

I use it exclusively on the front and rear rails of a Chevy smallblock when installing the intake manifold. I also use a very light coating around the water passages of the intake manifold gasket.

I also use it to "glue" cork valve cover gaskets to the covers.

oldbogie asked the question "When you put a blob on and drop an intake into place, do you have any idea where the squeeze went?"

If the RTV is used properly there will not be any "blob" to fall into the engine as he suggests.

The correct method of using RTV at the ends when installing an intake is to clean the surface material, apply the RTV, let the RTV "skim" over for about ten minutes or so (This will be dependent on the humidity and ambient air temps), then install the intake straight down without a lot of side ways movement.

Removal of the Permatex adhesives is time consuming and difficult. Requires scraping and the use of solvents.

Removal of the RTV is for the most part a pull and peel and then wipe with a clean rag operation.

I have never had any leaks when using RTV.

I also never had leaks when using Permatex. I did have problems removing components when using Permatex.

The choice is yours.

[ScoTFrenzel]

I've dealth with the FAA for 35+ years and using them as an illustration example is pretty worthless, as are most of their employees.
They are generally nice people with an authoritative Gestapo complex, and they like to cause distress to everyone possible, just as long as their actions do not cause themselves any hassle or "paperwork effort".

I do prefer the Aviation Permatex for many situations
as well as RTV for many, as do most all automotive manufacturers.

IMO the reason to use any sealer is specifically to prevent leaks in questionable areas. period.
If that product causes someone stress IF the engine/component has to be disassembled in the future, well that is their problem.
My concern is to PREVENT LEAKS -----NOW.

JMO

[pepi]

FAA is a joke for sure