do I need to use gaskasinch on the exaust manifold gasked

I am going to change my dads cracked exaust. What i need to know is do I need to use gaska cinch on the gasket when i put the new headers on? If there are any other tricks I should know please tell me.

No. Use RTV Copper - a very light coat (just enough to cover the gasket.) Don't use ANYTHING else - it will burn out!

I also like to use brass hardware when I put everything back together, and make sure there are "dish" washers (they're called "Belleville Spring Washers") on every fastener when you put them back together. If you don't have them locally, you can order them from MSC Direct (the bolts are 3/8"-16x1.25", and get Bellevilles to match. Use 3/8"-16 nuts in brass for the collector.)

I like the brass because it doesn't corrode, and doesn't gall or sieze on the iron when it gets that hot. There isn't that much strain on them anyhow, so brass is just fine. It's worth the time to get them, y'ask me...

5-90

Thanks for the info. The gasket I got was a fiber one. where would I get a brass one.

No brass gaskets - just use brass bolts.

The OEMR gasket is fine - and the RTV Copper helps out quite a bit - it's just that you'll find the hardware holding everything together is quite a pain to get out - which is why I suggest the brass (be VERY careful you don't break any bolts or studs off, or you're in for a world of hurt!)

RTV Copper should be available at any well-stocked parts house, and I've even seen it in hardware stores. It's easy to spot - the tube is copper-coloured. Make sure it's "Sensor Safe" (the automotive stuff usually is) and use a thin layer on the fibre gasket only.

Oh - if you are in the 1987-90 range, make sure you put a little Never-Seez (copper is best, but the nickel "silver" stuff will work) on the threads on both tube nuts on that damn thing. If you're replacing the EGR gasket, RTV Copper on that is also a help. If you are in the 1991-up range, ignore the preceding paragraph...

5-90

Kelley you are a man after my own heart. I check out your webb site and will be purchasing some stuff in the future. The headders are going on a 91 4.0l this is my dads rig. I have an 87 that I picked up dirt cheap with a dana 44. I have done many junk yard upgrades. Like you I dont mind paying for quality I just dont want to get ripped off. Thanks for all the great info.

Thank you! That's what I'm trying to do - I don't mind charging - or paying - for quality, but I'm not out to rip everyone off and I'm tired of being screwed myself. That's a guiding principle.

I've been talking to a CNC shop about getting the FCE, AW4 fittings, and the Belt Tensioner Knuckle started in production - so I'm hoping that I'll be able to post prices within the next couple weeks. There might be a proto or two of the headlamp harness coming along as well - hopefully in the next month of so. I'm aiming for a dead simple plug-and-play installation.

I'm also working on a design for sleeves for 760x U-joints (blame BrettM for that one,) and some other goodies I don't want to talk about just yet.

Hopefully, I'll be getting more going soon - I'll churn out ideas as fast as I can come up with them, or as fast as I can develop ideas that all of you send in. Frankly, I enjoy the challenge!

5-90

I'm currently in this situation with a question. Do you apply the RTV to both sides of the gasket? Or just one side? Head side? Manifold side?

I plan on reusing the original bolts. Should I use some type of anti-seize on the bolts? What Kind?

Both sides. I'd also replace the bolts with brass if you can get them quickly enough (check marine supply stores, or get them from a fastener house.)

Failing that, use NEW steel or stainless bolts (just to make sure they've got clean threads) and use LocTite #272 to retain them (any other formula will break loose because of the exhaust heat.)

And, make sure that you have the Belleville washers (the dish-looking ones) on all the bolts and nuts, since they help with clamp load spreading.

If you have to replace the studs at the ends and in the centre, I find it helpful to replace them with studs cut out of brass all-thread rod (which most hardware stores will have,) and that will be easier a little later. All holes are threaded 3/8"-16, cut the studs to about 2" long and the bolts are all 1-1/4" under the head. There are, I believe, either ten or eleven bolts and two or three studs (I've noted changes.)

If you use never-seez, reduce the torque value on the bolts by half (due to the lubricity of the compound) and make sure to recheck torque every year (because when the bolts have to clamp aluminum and steel subject to great heat, they'll work loose over time. I typically catch one loose each year when I do my detailed inspections.

5-90

brass bolts really? Brass nuts on studs I can see, but I think if you are concerned about corrosion I'd go with stainless bolts.

Its a coefficient of expansion and seizing issue. Brass is definitely better. By the way I recommend the spray can of Permatex CopperCoat for the intake/exhaust gasket.

Ditto 5-90, I used brass nuts on my downpipe, makes all the difference in the world when it comes time to remove them, no more broken exhaust studs for me. Check out 5-90's site and get yourself a copy of the MSC catlaog, more like an encyclopedia, over one million items in the book and it's free.

5-90 said:

And, make sure that you have the Belleville washers (the dish-looking ones) on all the bolts and nuts, since they help with clamp load spreading.

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Should I get brass Belleville washers or reuse the old ones?

5-90 said:

If you have to replace the studs at the ends and in the centre, I find it helpful to replace them with studs cut out of brass all-thread rod (which most hardware stores will have,) and that will be easier a little later. All holes are threaded 3/8"-16, cut the studs to about 2" long and the bolts are all 1-1/4" under the head. There are, I believe, either ten or eleven bolts and two or three studs (I've noted changes.)

5-90

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A point to add to your database, my '92 HO motor has two studs, one at each end and 9 bolts.

When I removed the nuts off the studs, the nuts locked up and the whole stud came out. When I replace the studs should I use brass nuts?

Belleville washers are always spring steel - but they're washers, and won't gall on the bolts like nuts can. It's OK to use brass nuts/bolts with steel washers - it won't cause you any trouble.

There are several good engineering reasons for the use of brass hardware that I won't go into right now - it just didn't get done for one simple reason - money. (I'd have to take a little room to explain all the whys and wherefores of it - but it makes sense once it's explained.) Brass costs more than steel (and I don't care. It's worth the extra money to me to use brass hardware.)

I knew eleven was a key number - I just couldn't recall offhand why (I've spend all of yesterday tearing my drivetrain apart and putting it back together...) The typical arrangement, then, it 9/2 or 8/3 bolts/studs. (I've seen both - the odd stud would replace the top centre bolt.)

The old Belleville washers can be reused, but it would be better to replace them (they don't cost as much as you'd think.)

If you replace the studs with brass, you can use brass or steel nuts (the key issue is to not have steel riding on steel - you can mix brass and steel in this environment just fine.) If you use a steel stud, DEFINITELY use a brass nut!

The principal issue at the manifold isn't corrosion (although is it related - just not as big a problem as undercar,) but seizing. Even undercar, brass would be better than stainless from a corrosion issue, because brass/copper won't seize on iron/steel. Stainless is still a ferrous alloy, and suffers from galling issues unless you go with an exotic CRES alloy (which will cost you two-three times as much as the brass anyhow.) Since the working forces are so low, just stick to the brass and make things simple for yourself.

I see no reason why the spray copper wouldn't work - I just wanted a little more "buffer" when I did the gasket. I also use RTV copper on the converter flange gasket - and DO NOT use any other sort of RTV on either one! Copper is the only one that won't burn out from the heat...

5-90

5-90 said:

I also use RTV copper on the converter flange gasket - and DO NOT use any other sort of RTV on either one! Copper is the only one that won't burn out from the heat...

5-90

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In the dozens of threads I've read on replacing exhaust manifolds, everyone recommends Permatex copper RTV or spray. Since I know you have experience, have you gotten a look at an exhaust gasket coated with permatex copper after it's been on for a while?- does the RTV burn up at all?- I ask because I used some as a temporary seal on an outboard motor and it got all soft and seemed to lose its sealing properties after about an hour of running. -

and what works better, the spray or the stuff in the tube?

just thought I'd ask,

thanks- B

I use the RTV - which works well and holds up nicely. There's no reason for the spray stuff to not work - but I wanted something that would fill a little better and that would be a little springier. Since the copper RTV actually has copper in, I'm sure that's what saves it. RTV copper also works well on "self-grounding" sensors that require a good electrical connection through the threads (since Teflon anything usually stops that. RTV copper is also conductive.)

Using it alone to seal an exhaust wouldn't work - since there's nothing for it to bind to. However, having the gasket as a substrate works very well - I've been doing it for a number of years without any trouble.

5-90

I incorrectly called the product I have used for years a Permatex product. It is from K&W and is copper-coat. It is not RTV. I hesitate to use RTV because the exhaust heat will burn up any RTV I have ever seen. It is not unusual for exhaust gases on a 4.0L to reach 1200F.

5-90 said:

Using it alone to seal an exhaust wouldn't work - since there's nothing for it to bind to. However, having the gasket as a substrate works very well 5-90

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That was the problem- didn't have a gasket, just used a thick bead of permatex Copper, when I replaced it with a gasket the next day it was really soft, it looked melted and slightly charred. (but it got me home without having to row)

looking on the tube of permatex ultra copper, it says not recommended for use on head gaskets. I would think the exhaust would get just about as hot-less pressure maybe-
but hey, if it works, it works.

thanks 5-90, old man.

-B