Now that I've blown out the third intake/exhaust gasket on my 223 inline, I want to consider some alternatives to the paper gaskets supplied by Clifford. I will call Remflex later today, but they don't list a 223 application on their webpage, so I'm not optimistic that they have one available for my motor. I can't find anybody making metal gaskets for this motor anymore, but wonder if I can't have a couple made up from dead soft copper sheeting. A couple questions.... Good idea or not so good? Just use the copper along with the Permatex Copper seal? Is the copper crushable enough to provide a good seal? Where would I find a sheet of stock? Is it readily available? A friend has a water jet so I can have it cut in any shape/design that I want. I'll use a new gasket as the pattern, but need the material first. What thickness is recommended? Thanks guys.
.042 would probably be fine for the experiment. I'd use the Permatex, or even aluminum spray paint (old, old trick). I'd take a very careful look at the flanges first, though, especially if it's blowing out in the same place(s) each time. Dead soft copper is also known simply as annealed copper...shouldn't be too hard to find locally.
I cut out a set of .080 copper sheet stock I bought from the scrap steel place where I live, the gaskets have been in my 454 for years now and I haven't had one problem. I used ultra high temp black permatex silicone in my 350 chevy with no gaskets on sanderson headers, and that was recommended by sanderson. I must admit that I don't have many miles on that engine but it never did blow out anywhere. good luck
A couple of problems...design flaws. The center exhaust ports are siamesed and generate tremendous heat. That is always where the failure is. With the Clifford intake being aluminum; their headers being steel; and the head being cast iron, the materials expand and contract at very different rates. Also, I suspect that the exhaust ports are warping slightly with the heat. It's a tricky setup to try and seal. If I use the dead soft copper, is it necessary to have the bead rolled around each port opening to assure a good seal? Or will the Permatex be enough? The black Permatex or the copper? Again, many thanks.
I have made several head gaskets from .041 copper. I bough6 part of a sheet from a local dealer. Was not easy to find as I didn't want a 4 X 8 sheet. $$$$. I started with half hard copper. (Cuts better) When cut out I sooted one side with acetolene from my torch then turned on some Oxy and heated the gasket from the other side to burn off the soot. This anneals the copper to a dead soft condition, I am told. Worked fine in my Plymouth and the 455 Pontiac that blew lots of store bought gaskets
Could it be that your intake or exhaust manifold or both are not true to the head? Have you put a straight edge on them before blaming the gasket. You've blown out three gaskets, just sayin'...
Just tore the intake and headers off and laid a straight edge on the head. Looks pretty straight. I'm beginning to think that the bolts that were too long! I think the bolts were bottoming in the holes and weren't completely clamping down on the flanges. When I would tighten them up, they would feel tight, but they were actually bottoming out. I didn't build the motor or do the first replacement, but I think my diagnosis is correct here. Wouldn't be the first time that happened and the good people at Clifford wondered if that might be the case. When I pulled the old gasket off, it had a couple of leaks. I think the thing to do is to double gasket and use the Permatex copper sealer. And the shorter bolts. Other ideas? I did talk to Rem at Remflex this morning and unfortunately, he doesn't offer a gasket in a 223. And doing just one is pretty expensive. So he needs a miniumum run of 5, plus the set up fee. Any other 223 inline guys that need a gasket? I might need to go into the business on them. His gaskets sound great. A couple weeks turn around time. I'm stewing it over. I've got the week off and unfortunately, I'm not headed to the Lone Star Roundup. Maybe I'll monkey around in the driveway with this heap and see if I can't do a little better job with a conventional gasket. Can't do much worse and it will keep me out of trouble....
If you haven't already, I'd put a straight edge on the intake and exhaust manifolds before you put everything back together. Just in case you only checked the head trueness like your post. Good luck and let us know what happens. It'll help somebody else out later.
Now I am quite certain that the problem in the past was that the header bolts were bottoming out. Three of my machinist buddies have pointed out that the maximum holding power of a bolt is the number of threads = 1 X the diameter of the bolt. Well, one says it is 1 X the diameter, the others say 1 1/2 X the diameter. Here is what they all said: look at the thickness of the nut that is appropriate for the bolt. That is all the thread you need for maximun holding power. Wow, that isn't very much. I always figured that the more threads that were gripping, the better the holding power. So in the past I made the bolts as long as possible. A couple were bottoming out in the head and not allowing the gasket to crush to its maximum thinness. Over time, the gasket blew out. We'll see how this composite and steel gasket does over the paper ones. So far so good. Here is what I learned about dead soft copper gaskets. Great on many motors. But if you have any imperfections in the head or any surfaces that won't mate dead flat, the gaskets will leak. They need to have a bead stamped into the surround to make them leakproof. Most shops can do that on the round ports (on my engine those are the intake) but can't do it on square ports (that's the exhaust side). But if you are looking for custom copper gaskets, these folks were terrific and had the best prices of anybody I spoke to: http://www.lubbockgasket.com/index.html And if the current gaskets don't work out for me, I'll bite the bullet and have several sets made by the Remflex folks. Now you talk about knowledgable, nice people. Very straight shooters. I liked 'em. I spoke at length with da man hisself, Rem. http://www.remflex.com/
I always went with 1.5 diameters for tapped hole max holding power. I'm sure either 1 or 1.5 would be fine. I'm surprised it doesn't use exhaust studs in place of bolts, that takes the bottoming out thing out of the equation. I would use studs/nuts or shorter bolts and of course flat and lock washers. Try that with the Permatex copper sealant. Worst case, do you have an old gasket for a pattern that someone could make copper ones out of? Bob
Bob, the copper isn't the problem, it is finding somebody who can roll the raised seam around the edge of the square exhaust port opening. I can find the materials and have plenty of gaskets for a patter. But getting the seam done is more challenging than I would have thought. Everybody can roll the round opening. Can't find anybody to do the square ones. Another point.... The head is cast iron. The intake is cast aluminum. The exhaust manifold is steel. The custom gasket guys all say that without the sealing characterisitics of the raised ring around the port opening, it just won't button up properly. Think about it. I now have three different metals expanding and contracting at different rates. If I use a flat sheet copper gasket, now I've introduced a fourth metal that is also moving around. But if I can find somebody to cut the gasket and roll the bead in the surround, I'm good to go. Otherwise, I'll need to use a composite gasket like the Remflex. The copper guys tell me that even the softest of flat sheets won't compress enough to guarantee a seal without the raised ring. And if there are any imperfections, it will very definitely leak.
I was unaware of the rolled flange thing. You might try bolting it up with the composite gasket and bolts that won't bottom out. Bob
Spend a little time making sure the header flange fits. The iron head and aluminum manifold will have machined surfaces, are the header tubes welded to the flange on the head side? I have a set of Hooker headers for a GM 292 six that were terrible in this way. They needed additional welding, cleanup with a rotary file and flattening with a grinder before the openings matched the ports closely enough to stand a chance of sealing. Put a gasket against the flange. Do the openings match? Hold the flange against a flat surface, do you see daylight between them? Can you slide a piece of paper between the flange and the flat surface in some places and not in others? Check and file/ grind as necessary, repeat. A table saw table makes a good flat surface for this- machined cast iron, probably flat within +/- .005". Good luck.
Find a shop with a manifold sanding table, have them run the manifold on it to tru it up, just did this with a leaky 235, and have done it with the Cummins truck engines, makes a world of difference, there is no reason for a 223 to blow even the paper gaskets. If your having trouble locating some try Olsens Gaskets in Washington.
Hope I'm not asking a dumb question here...is the proper torquing of a bolt affected by heat? Will I get a different "tightness" if I torque the exhaust gaskets when the motor is hot as opposed to cold? Should bolts be torqued properly only when the metal is cold or does it not matter? I realize that I need to tighten up the bolts to crush the gasket, but I am asking a torque question here....
There are a couple of different answers to this question, but the shorthand version is that I would install it cold, run it through a heat cycle & retorque warm, & re-check after a week or so of driving- then again after 2-3 weeks. In reality, chances are that after the initial tightening and possibly after the first retorque, you won't notice a bit of change.
Yes, I understand that part, but I'm asking a slightly different question.... Is "torqueness" of a bolt affected by heat? If I torque an exhaust bolt and the motor is cold will I get a different tightness than if the motor is at operating temperature? I've never been told whether bolts should be torqued cold, at operating temperature, or if it makes no difference. Part of what I am concerned about is that I don't want to shear off the head overtightening if the motor is hot. So, what's the answer? Hot? Cold? Doesn't matter? I dunno, but I bet you machinists do.
Well, what I was trying to say is that there's no definitive overall answer to the question...lots of variables...and therefore it's possibly better to bypass & go directly to practical experience. One thing to consider is, as you discovered, "torque" really means nothing in terms of tightness. It's the overall "stretching", or residual tensile stress retained, of the fastener, assuming there are no outside forces involved. That's one reason why I tighten connecting rod bolts using a stretch indicator...I can see what's actually happening to the bolt. As you probably know, for many head gaskets, the maker recommends that you do a warm retorque. Most people think that this is to compensate for expansion. Well, if you think about it, if you achieved "X" amount of stretch when everything was cold...in theory, as the heads and block heated, they would expand and if anything increase the stretch even more, the more so as the heads will expand more than the block, due to higher temps. One could ask, "Won't the fastener grow as well?" They do, but as you are normally talking about some sort of steel alloy, sometimes fairly exotic, with its own interesting internal stresses, and not a cast iron part with various holes, passages, etc., they don't change length nearly as much. (Unless the fastener has exceeded its allowable stretch, in which case you have other more immediate problems.) The recommended torque (and therefore stretch) should compensate for any growth along that "vertical" axis, if the engineer did his job. In reality, you retorque heads warm because as they expand, and the block expands, everything tends to move more along the "horizontal axes" and as it does, the gasket coating tends to spread out, the layers compress, and you generally lose some tension. So you go back and increase the tension again. Exhaust manifold or header bolts are the worst in this respect because of the materials, design factors, and temps involved, which is why I typically retorque at least once warm, and check it at intervals. Once the gasket is finally seated, if everything worked, you don't have to touch the bolts again, perhaps for years. There's a lot of other variables acting here- different expansion rates, "class of fit" of the fasteners, fastener finish, cleanliness of the threads, lubricant used, and quality of the fasteners as well. Chevrolet fans don't particularly want to hear it, but the quality of OE FoMoCo head bolts and main cap bolts is much, much better than GM fasteners. However, the GM pieces work for what they were intended to do. There are several factors involved in all of this from the fastener's point of view- residual tensile stress, residual shear stress (if any), length of the threaded area.....blah, blah, blah. Temperature, so long as it doesn't exceed the limits of the materials involved, is just about at the bottom of the list, as long as.... The bottom line (to me) is that you can assemble either cold or warm- most people choose cold for obvious reasons- but it's always a good idea to retorque after at least one heat cycle, and often several. If the fastener is not under critical loads, like a timing chain cover, you might not even retorque at all. If it's under load, better do it. Now ya see why I didn't quite answer your question directly...the simple answer is "doesn't matter so long as you retorque."
Homespun, man, you are good.... A concern: Since the center ports generate tremendous heat, does your practical experience teach you that it is easier to strip out threads or wring off a head when the bolts, etc. are hot, cold, or bad stuff happens at any time? There is one bolt head that is just impossible to get a socket or box end wrench on. No other choice but to use an open end. Yesterday while the motor was hot, I was tightening up this particular bolt (new, Grade 8) and I noticed that it wanted to round off a corner pretty easily. So I got to thinking that maybe the heat would deteriorate the hardness of the bolt??? Maybe a defective bolt to begin with?? A concern, or am I just thinking too much??? At one time I had a boss tell me, "Pete, ya' gotta stop thinking so much...." He might have been right.
Pete, this probably qualifies you to be an engineer! But there is a fine line between thinking too much and not thinking enough. I'd prefer to over-think if I had my choice. Fortunately my little brain doesn't often have to worry about over-thinking anything. If you have the sort of mind that appreciates this sort of thing (i.e. fasteners), and aren't willing to undergo therapy to rejoin the real world, I'd suggest reading the Nuts, Bolts, Fasteners and Plumbing Handbook by Carroll Smith. It's out of print and used copies are ridiculously expensive but a library might be able to get it for you. It has an amazing amount of information of practical use and I still re-read it every so often to clear out the cobwebs of my brain. His book Prepare To Win is still in print and has a bit of the same stuff.
It seems to me that if I wanted to duplicate the raised strip on a copper gasket I made I might make a gasket out of .060 material and then go back and mill off suronding material about .020 deep to leave a raised edge somewhat like a rolled deal. Or what I actually did once on a head gasket I made was to solder a .040 copper wire to the copper gasket to form a ring around a nonuniform combustion chamber. Worked very well for me.
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