Posted by Sherman in Idaho [24.32.202.166] on Tuesday, July 16, 2013 at 01:24:41 :
In Reply to: Cani drill out the bolts? (manifold) posted by Sterling From TX [99.98.76.231] on Tuesday, July 16, 2013 at 00:58:58 :
I'm confused that you keep mentioning bolts. Every engine I've seen has had studs in all positions to hold the manifold on. It wouldn't surprise me a bit if some previous owner put bolts in, but I'm quite sure they're supposed to be studs. Studs are hardened and are next to impossible to drill out without the bit "walking" into the cast iron nearby. I have never had good luck attempting to drill out any remnant of broken stud or bolt from cast iron. If it's mild steel, and I center-punch it carefully, and work the drill bits up in size until it's almost cutting into the cast iron (the hole always ends up way off-center no matter how carefully I start), there's a chance that the heat and vibration and removal of some material will loosen things up enough that I can snag what's left with some tool and unscrew it, but most of the time, I end up with a big hole in the casting and have to either tap it for a larger bolt or put a helicoil in it. I don't recommend attempting to drill a bolt or stud out unless you really have absolutely no other option. If you must try it, heat what you can of it red hot with a torch to anneal it first.
I also don't know what you mean by "flush with the manifold". Does that mean you already cut the heads off of them? If so, you should be able to get the manifold off, if all it's held on by is the gasket and the rust between the bolts/studs and the holes in the manifold. Be sure you have all of the nuts off of the studs (or all the heads off the bolts), including the one that's hard to see up under the carburetor. Then hammer one or more old scrapers, putty knives, etc down between the manifold and block and start prying. As I recall, your engine is extremely rusty. The usual rust tricks apply -- penetrating oil, candle wax, heating the studs/bolts red hot, etc.
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