well none of mine stripped or sheared off. I took the opportunity during the winter months to go out in the garage and put a drop or two of Kroil on each stud every few days for a month.
that included the studs where the manifold attaches to the down pipes.
once the manifolds were off, then I re-applied the Kroil to the stud where it met the block. did that for several weeks and using the double nut technique and some patience, they all came out easily.
I didnt need a torch of any kind. What I did do is replace all the studs with stainless steel ones from one of the usuals.
that is very true!! I doubt I would have made any money in the profession with that technique.
I understand the need to expedite removal and that not everyone has the luxury of taking a lot of time. I didnt mean to suggest my method was the best or only way. plus I do realize I was lucky as my car never spent years parked out behind a barn or any other harsh conditions.
On some carsāusually long-term restos, or custom fabrication workāI did have time to do the soak-n-wait routine.
On Tweety, I replaced the studs with Allen-headed bolts, slathered old-fashioned lead-based antiseieze on them, and, up to the day I loaded it on the truck, bound for its new home, the flanges never came loose, and were free.
If I understand correctly, the OP was concerned about removing the studs so that he could Jet Hot or otherwise refinish his exhaust manifolds. Thereās no reason to remove the studs to remove the manifolds, just take off the brass nuts and Bobās yer dadās brother! As an aside, when I did my engine rebuild a few years ago, all of the intake and exhaust studs came out without any problem. I guess that I was just lucky.
More than ten minutes, probably an hour or so. Some of the nuts underneath the manifold are a bear to get to and you need a long socket extension to reach the manifold/down pipe nuts from underneath. I had to use two long extensions joined together with a length of about 18-24" as I recall. The nuts are, or should be, brass, so they donāt tend to bond to the steel of the studs. You shouldnāt need heat, hammer or lube.
the other option that worked for me ( on the down pipes )was a crowfoot adapter on a socket wrench with extension from the top. I have done it that way and from the bottom where the nuts always seem to fall and hit me on the foreheadā¦
a trick I found was to remove the front manifold completely before trying to get to the rear one. that way I could reach under and around easier. ALTHOUGH as I type this it dawns on me that my Alternator is mounted up front because my car was an A/C car. so I dont know if that will help or not. but might be worth trying.
I would start with the nuts to the down pipes, if they give too much trouble then step back and re-evaluate.
So Iām curious. Even if you successfully remove the nuts to the down pipes AND the manifolds, you still have studs engaged on both ends. So how do you get the manifolds off? You can lift them because of the head studs, and you canāt drop them or pull them horizontally because of the down pipesā¦
Seem to me youāve got to get some movement in the exhaust systemā¦
the down pipes will drop down. I suggested a floor jack to support them until you are ready. they arent going to hit the floor or do anything catastrophic, but the jack simplifies putting them back together. there is plenty of give in the down pipes to get them off.
OK, heat shield installed, and without drama! Itās mirror finish so actually quite difficult to photograph without losing perspective as it reflects everything. I deliberately put my reflection in one picture so you appreciate the angle - what Iām trying to show is that the gap between it and the existing bottle heat shield is tight, about 3mm, but itās enough. The bolts are reflections of each other in the manifold heat shield.
Now I turn my attention to what might be newly stressed by the heat being pushed down and back rather than previously escaping upwards, melting my grill paint as it went. There is a cable behind the manifold that emanates from the back of the engine, snakes under the braking system and disappears into the bulkhead through a circular rubber gasket above the expansion tank. What is this and does it matter if it meltsā¦?
speedo cable. the casing will melt if it gets too hot. way back in the day my dadās mechanic brilliantly re-routed it down from the angle drive so it went under the transmission and was laying on the exhaust. the outer casing was melted completely off, but the cable still worked. not perfectly tho, the speedo jumped about +/- 10 MPH
Ha, was actually thinking rev counter. OK, will strap it to something.
One thing I forgot to mention was that I had to remove the dipstick bracket so the dipstick is now just leaning against some tubing. Might need to strap that to something, too.
All this heat damage brings me back to something I thought within the first minute of driving it - that it needs either a 5 speed or a different diff. 65mph is 3000rpm, which can only make heat every time I go to the pub.
Rob
Your heat shield looks good! Mine is not as close to the brake bottles as yours is. Looking at your photo it looks like the shield could be moved closer to the head, as the holes it the shield are slotted.
Robert
