Which color rtv adheirs to rubber gaskets the best

[heavychevy91]

Use the gaskets on both sides. Take the rubber end gaskets and throw them in the trash. Go down to your local GM dealer and pick up some GM Engine sealant or GMS. Its only like $11. Black RTV will work too. Lay down a 1/4" bead. Torque intake and you good.

http://www.rmsautoparts.com/prodimages/88861417.jpg

[Blazin]

Okay, first thing you do is when you go to buy your new Felpro intake gasket set. Stop in at the local Ford dealer, and pick up a tube of the gray silicone they use for the 7.3 diesel oil pans. You will never ever again ask what is the best silicon to use!
( FYI its actually made by International Harvester, as the 7.3 is an IH engine. They sell it as well if you have an IH dealer around. )
Second thing you do is open up that box of brand new gaskets, reach in, take out those rubber end gaskets and toss them in the nearest trash can!
Clean your heads, intake, and block up really good, no old gasket material left on there. Put a dab of silicon in each corner, set your new side Felpro gaskets in place, then run a nice 1/4" plus bead of silicone along the front and rear of the block. run that bead up over the little bottom tabs of the side gaskets. Set the intake on nice and slow, strait down. Torque the bolts in a circle from the center out. One the silicone is dry you can use a razor to trim any that has spooged out on either end, or leave it.
In a pinch I have pulled the front rubber gasket out from under the intake on a 350 with a dual quad high rise in a 76 Vette. Cleaned the bejeezes out of what I could with brake clean, a slim screw driver, and a rag. Shoved a pant load of the silicone I spoke of in under the intake, let it sit over night, fired it up in the AM, and had no more leak.

We also used it to stop and oil leak on the side of a front cover of an NC14 Cummins in a Western Star last summer. Its still holding after 50,000 more miles! Same deal, dug out a bunch of the old gasket above and below the offending area. Brake clean the heck out of it, filled it in, let it sit over night. Changed the oil, and its been good. 3 hour fix rather than a 3 day repair!

[zieg85]

Okay, first thing you do is when you go to buy your new Felpro intake gasket set. Stop in at the local Ford dealer, and pick up a tube of the gray silicone they use for the 7.3 diesel oil pans. You will never ever again ask what is the best silicon to use!
( FYI its actually made by International Harvester, as the 7.3 is an IH engine. They sell it as well if you have an IH dealer around. )
Second thing you do is open up that box of brand new gaskets, reach in, take out those rubber end gaskets and toss them in the nearest trash can!
Clean your heads, intake, and block up really good, no old gasket material left on there. Put a dab of silicon in each corner, set your new side Felpro gaskets in place, then run a nice 1/4" plus bead of silicone along the front and rear of the block. run that bead up over the little bottom tabs of the side gaskets. Set the intake on nice and slow, strait down. Torque the bolts in a circle from the center out. One the silicone is dry you can use a razor to trim any that has spooged out on either end, or leave it.
In a pinch I have pulled the front rubber gasket out from under the intake on a 350 with a dual quad high rise in a 76 Vette. Cleaned the bejeezes out of what I could with brake clean, a slim screw driver, and a rag. Shoved a pant load of the silicone I spoke of in under the intake, let it sit over night, fired it up in the AM, and had no more leak.

We also used it to stop and oil leak on the side of a front cover of an NC14 Cummins in a Western Star last summer. Its still holding after 50,000 more miles! Same deal, dug out a bunch of the old gasket above and below the offending area. Brake clean the heck out of it, filled it in, let it sit over night. Changed the oil, and its been good. 3 hour fix rather than a 3 day repair!

This should be in the technical pages... Thanks Blazin, I learned something new about the best silicone on earth it sounds.

[VileZambonie]

Everyone has their own methods but I'll tell you my $.02 from experience as well from my continuing relationship from our friends at Permatex. I have Permatex come in twice a year and put on a certification training for chemical gaskets and sealants for our students. The first thing they'll tell you is don't use the blue (even their own product) on anything. You may ask why they sell it still but their response is basically people buy it like crazy still because it's the least expensive. It's hard to take a product off the market that people buy that makes your company $$$ Take a whiff (vinegar) and you'll know someone is using blue from a mile away. You should essentially consider 3 RTV's (not including anaerobic sealer) that won't fail you.

1) The Right Stuff - this will work on just about anything and is hands down the best product on the market as an adhesive sealant. It's expensive but it's "The Right Stuff" Where I would caution you to use this is on a component that you plan to disassemble again. Example: timing cover if you're planning on playing with your cam timing etc and need to pull things apart from time to time this is not the product for you. You will essentially destroy the timing cover taking it off. I can use more examples but you get the point.

2)Ultra Copper - Use this for any hi heat applications. Ex around exhaust etc really good product. Some guys make a small bead around steel gaskets and let the RTV set before they install them especially if they're going to be pulling headers on and off frequently. Yes it really works on exhaust

3)Ultra Grey - Great for components that you may need to take on and off without destroying. Choose the right stuff for permanent connections. The Big 3 offer similar products that are pretty good too and I swore by them until I started using the higher quality permatex products.

For the SBC and BBC intake manifolds, it's a well known fact that the end seals are not to be used. Make sure the area's are clean. Take a center punch and punch a series of impressions across the flat deck surface where the end seals would go. This creates peaks and valleys and helps guarantee a good seal. You can do the same on the manifold side as well.



Place your gaskets accordingly and a dab of the right stuff can hold them in place on the ends. Lay a bead of the right stuff across the flat surfaces where the end seals would go overlapping the gaskets on the cylinder heads. Place the intake manifold carefully into position. I suggest using new intake manifold bolts like ARP and putting Permatex 56521 thread sealant on the bolt threads as they protrude into the lifter valley and can creep oil up onto your manifold.

Make sure you tighten the bolts in sequence and in steps to ensure proper installation. Go around the sequence again after you achieve the torque values two more times.

SBC -86 35 lb-ft
BBC -86 30 lb-ft

I would suggest if you look at this to double check your specific year for sequence and final torque value

[454Man]

Right stuff it is... I heard good things about this company. Do you think a hand held engraver will be good as a hand punch? Trying to save time. I use the grey on all my water related parts.

[VileZambonie]

http://www.permatex.com/videos/video_gasketing_eng.html

[VileZambonie]

Quick story, I had a customer come in a few years ago with a Mitsubishi Mirage. It overheated and the shop she took it to put a radiator in it. As soon as she drove down the road it overheated again and blew the cap off of the radiator. So she donated the car to me. We pulled the cylinder head and measured over .180" warpage! So we put the head back on with the right stuff as a head gasket and the car lasted us 4 years as a training vehicle before I scrapped it. I would never do this for an over the road vehicle but we sure got our usage out of the car for $14 worth of RTV.

[454Man]

Quick story, I had a customer come in a few years ago with a Mitsubishi Mirage. It overheated and the shop she took it to put a radiator in it. As soon as she drove down the road it overheated again and blew the cap off of the radiator. So she donated the car to me. We pulled the cylinder head and measured over .180" warpage! So we put the head back on with the right stuff as a head gasket and the car lasted us 4 years as a training vehicle before I scrapped it. I would never do this for an over the road vehicle but we sure got our usage out of the car for $14 worth of RTV.

really? That good of a sealant.that is where my money is going then

[Blazin]

I have used the ultra copper on exhaust gaskets before as well. It is pretty good stuff. I have also used the Right Stuff as well. I like the gray Ford cone better.
I had a thermostat to do on something, I don't recall what it was, I am thinking a Jeep Liberty but not positive. Anyway what ever it was it was not possible to get two hands in there to hold the neck, and put the three bolts in. I did the best I could to get the stat back in, with the gasket and neck back on. It leaked. Boss says you want me to get another gasket? I said nope! I used the Ford cone, stuck the neck in place, walked back over to the bench got the bolts, walked back over to the rig, reached in one by one and installed the bolts. The Ford cone held it in place without bolts.
 I will say this for it though, rearend covers will get damaged if they are thin, and or you don't use it sparingly.
There is no gasket for a 7.3 oil pan. When you buy one from Ford, it comes with a tube of this stuff.
They are so poorly stamped that if you set it on the bench you can meassure a good 1/4' under one or the oposite corners on all of them.
Set it on the motor dry and you could about toss a cat in between the pan and the front cover!

[454Man]

Glad I don't own a fix or repair daily

Sent from my T-Mobile G2 using Tapatalk 2

[Blazin]

7.3 is an International engine. Only thing Ford about it is the truck its in.
They are a great motor, I know of dozens with over 300,000 miles on them with minimal problems. The biggest problem is the fact that the oil pans, oil cooler, and fuel lines rust out!

[454Man]

Ok so I used the " right stuff" on my rear diff to see if it would hold... small drip at the bottom of the cover. I guess ill be looking into the ford or gm stuff for my intake. If the right stuff didn't "skim" over so fast id use it I don't see it sealing my intake:(

[bd]

OK so I used the "right stuff" on my rear diff to see if it would hold... small drip at the bottom of the cover.  I guess ill be looking into the ford or gm stuff for my intake.  If the right stuff didn't "skim" over so fast id use it I don't see it sealing my intake

For what it's worth, I've used many different silicone products over the years, including two iterations of GMS, various Permatex/Loctite products, OE sealers, etc.  They all work, some better than others for specific applications.  The real keys to success are preparation and setting of the pieces once sealant is applied. 

When you do your intake use a flat, hard sanding block, +6" long (I use oak that I machined flat) and ~120-grit emery wetted with solvent to initially clean and prepare the sealing surfaces.  The 'planer' sanding block helps keep flat surfaces flat, while removing slight surface imperfections and high spots.  Wirewheel, chase and thoroughly clean all the bolt holes and bolt threads.

Do a "test fit" and dry run - get everything set up and organized for quick efficient assembly, making sure nothing unnecessary is in the way that may interfere with assembly.  Lay out the bolts; precoat them with thread sealant or torquing compound as needed.  Wash down the sealing surfaces with ether (starting fluid) or other volatile solvent that doesn't leave a residue.  Make sure the surfaces are totally clean, free of oil, lint, etc, and dry.  Smear a thin layer of silicone around the coolant passages of the gaskets, goop a dab of silicone in the corners of the China Walls, and evenly apply the appropriate width silicone bead (~3/8") along the top of the walls.  Quickly align and set the pieces being careful not to slide them once set, install the bolts, assemble, torque, and then allow sufficient time for the sealant to cure.

I generally prefer Ultra Copper for most routine gasket sealing applications, because it's readily available, inexpensive, makes disassembly easy, tolerates a broad range of temperatures, it's O₂ friendly, and it consistently works.  Yet, there isn't a single silicone sealer that does everything perfectly.  You may have to be more selective for problem situations.  The IH sealer is definitely an excellent product!

For thread sealing I use ARP Teflon thread sealant, Teflon tape, or the appropriate Loctite resin.  For press-in lip seals I often smear #2 Permatex around the outer circumference or set the seal with Loctite, depending on circumstances.

[454Man]

Ok so I took off my intake and found out really quick why the ends where leaking. The sealer wasn't sticking to the flat shinny surface Of the ends, but it stuck to the engine with no prob. I took my engraver to the ends of the intake and the water ports, fingered on some sealer to the intake and engine let it cure then whent back with another thick coat and then some wide beads on the engine ends. All is well so far. I let it sit overnight till 2 the next day. Hope it stays sealed

[thefarmboy21]

Every book, magazine article, video and engine builder I've ever acquired knowledge from says always use a nice fat uniform bead of RTV and toss the rubber ends because they push out. The key to RTV is a clean dry surface. The way I was taught and the way I've did every single engine I've built and helped build to date is small amount of RTV around coolant passages on both sides of gaskets, then thick beads on front and rear (I make them about 1/4" tall and as wide as the block face, so about 1/2") and then drag the RTV into the corners of the gaskets where they stop on the edge. I have yet to have ANY of the probably 10 or so, motors (mostly 350's, couple mopar and a 454) have an intake leak.

***Also I ONLY use Permatex ultra Black! Buddies have good luck with red but I HATE the blue!