Okay after having a shop install Ramshorn manifolds, dual pipes etc last year, after a few hundred miles started to hear a tic when under load on the drivers side. Rather than bitch at the shop I removed that manifold and dressed everything flat with a file, they should have probably ran it over a belt sander but they didn't, laid a bead of Copper permatex on both sides of the heat shield &c and the tic was gone for about 1500 miles. It's back now. So what's the best attack on this? A few choices, could remove the heat shields and use no gasket at all - though I guess the heat shields, that sort of act like a gasket are important enough that Ford thought they were necessary - or, use the thick gaskets that were included with the manifolds. Using the gaskets and the heat shield both seems like it would be more likely to leak, but I dunno?
Yep, I torqued them cold & hot and they settled in after a couple cycles but the tic came back. Ford never used gaskets either. The manifolds always include them though?? Using RTV is kind of a rookie move but I figured if it worked IDGAF. It didn't work though, ha ha. So I plan on having the manifold resurfaced or whatever it's called for flatness, but not sure what to do, or not do, with gaskets or, the heatshields. Pulling the manifold twice is plenty. Or should I bitch at the shop that did the work?
I did a similar repair on my off-topic Olds wagon. Both exhaust manifolds had been leaking and eroded the exhaust ports to a point where new gaskets would not seal. I used the red high temp rtv (I forget what brand!) on both mounting surfaces and the new gasket. Make sure everything is really clean! After getting everything torqued up, I let it sit for a couple of days to make sure it all cured. It's been over ten years and many thousands of miles with no leaks.
Yep, just on the drivers side. If the pass. side goes it would be more of a pain as the dipstick tube is routed through the manifold and would have to come out too. Not a big deal I guess. I cleaned up the mating surfaces with carb cleaner and all that, good prep always helps in shit like this, but I guess it wasn't enough. I just took off the major grind marks on the manifold thinking it should be enough. The head surfaces look fine, no erosion that I could see.
I had a 390 OT Mustang with a persistent manifold leak, made my own gaskets from .050 soft copper and that took care of the problem.
Well now if you do take the manifold off again you may see where she is blowing through at, I had the problem on a straight six Chevy and the manifold was warped. Had it surfaced and problem fixed. Sent from my iPhone using H.A.M.B.
Whether engines from the factory had no gaskets or not, gasket sets have them for a reason. I'm not familiar with the temp use of copper Permatex either may not be high enough for continuous 900* use. I've had the heads off my Y-block and used gaskets and have not had a leak in 5 yrs.
Gasket sets have them because they get more money that way. They are not needed on many engines, and they let the manifolds burn or warp under severe conditions, because they reduce cooling of the manifolds. Try without gaskets...might solve the problem.
Well that's some things to think about. Thanks. And other than the copper gaskets, I'd already chewed on most of them. Have to lose those spiffy heat shields, wonder if they might be part of the problem anyway. Might try getting the manifold resurfaced and try no gasket. Permatex Ultra Copper is supposed to be good stuff for manifolds. But shouldn't be required from what I've read. Thanks again, we'll see what's what.
Once the manifold is off, you should be able to see where its blowing through. Even from the outside you may see a light-gray trace where it leaks.
Yep, I should crawl around and see if I can find it. Anti-sieze or graphite would be good to use if installing manifolds bareback right? So they can slide.
All 3 flanges need to be flat AND coplanar to each other. Check with a straight edge. Could be the ports on the head too. Just cinching down a warped manifold won't stay It will "work" under heat cycling and loosen the bolts. Surface the manifold if needed or copper gaskets if the head ports are off Sent from my SM-G550T using The H.A.M.B. mobile app
gaskets are used as the manifold will move as you heat and cool it its relieves and makes stresses from the casting and also when you untorque it it will move around ( unbend ) this is why in the old days we cut the castings on some of them between bolts and on newer vehicles not equippped with tubular manifolds they castings are cut ( the BBC in the last years of production the manifolds they cut each port area loose between the bolts so it would move and they still had bolts and studs break and the ticking, and several people have the spreader tool that you had to use on chevy manifolds to get them to fit over the studs or bolts , never use permatex for a exhaust gasket, silicone just pushes out under pressure its made for making a liquid seal , its pliable like a nose booger , a soft metal that deforms is better , the thin foil composite gaskets are best ( felpros,/victer reintz ) copper is ok but still hard .
I don't remember if they had locking tabs on those engines, or not, on the original manifold bolts. Chevy rams horn manifolds had lock tabs on the outer bolts, so they would not loosen as the manifold moved around. Also the outer bolt holes were larger, to allow this movement. Rams horns didn't have the problem of bending in over time, like the under the plug manifolds did (the design used during the 1970s on most cars). The old style of gaskets with the thin layer of metal embossed over the dark composition material, is designed to allow the manifold to move around. Locking bolts of some type would be good...at least on the bolts around the end ports.
Yeah I wondered about that, it's not enough to take a file and make each flange flat, the whole shootin' match needs to be flat with each other. At least I guess that's what "coplanar" means. So fellas should I probably ditch the heat shields?
Do you have a big flat file? Mark the flange sealing surface with a sharpie and run a big file across the surface. This will show where the low area(s) is/are.
No lock washers. They are just drugstore bolts with thick washers iirc. I retorqued them a few times both cold and hot and they seem to hold now. Might put a wrench on them and see where they are at, but I figure reefing them down too tight would maybe crack the manifold ears. One problem is all the machine shops around here dried up. Used to be ya couldn't throw a rock without hittin' one. If I had a big enough swatch of emery could maybe try using some plate glass and the figure 8 deal to sand and get everything pretty damn flat redneck style.
know what you mean about a true machine shop , the real ones all closed down and now its basically assembly from a kit shop with a boring bar . and oven . a old long belt sander ( table style ) can get a decent surface on it . I know on several of the old ford trucks the heat sheilds incorperated a aluminum manifold gasket with it . but I do not know if they were that way from the factory as the ones I got had been worked on many times by the time they came to me . and they were with the log style front x over manifolds
These are what they look like, stole this picture from here. They were old stock used, maybe they differ slightly but this is the same deal. I figured using a gasket along with these would just provide more opportunity for leaks. Maybe the shield could be secured some way without being an integral gasket, but I dunno.
No machine shop close by? Do you have access to a large belt sander? I have run Chevy ram horns across my belt sander to remove the build up on them . It gives you an idea whether they are warped or not before you go to a machine shop with them. I also have a good machinist's straight edge that I check flat surfaces with.
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