What CC are these heads... I broke 3 exh bolts off in them and need to get this thing running tomorrow, I have a set of 882 and 434 350 heads and might use those as a quick fix... however, I want to make sure I'm not replacing a 58cc head with a 76cc head and kill compression... Need help asap!!
This info may be to late but I say Fix the 305 head if possible.
If the studs are broken off above the surface then heat them till cherry red and as they cool down melt some candle wax on them. This will make them easier to back out, that is unless you have bottomed them out. I suspect though that they are broken off below the surface. If this is the case then use your manifold as a guide and make some kind of a drill guide to center the bit. Or you can do it by free hand drilling if you center punch and start with a small bit and keep stepping up in size. If you have a die grinder use a 1/8 inch carbide bit. Then once you get a hole all the way to the bottom of the bolt start cutting the rest of the bolt out. Cut to the threads in three places around inside the bolt. Try not to let the bit chatter or you will break it. You should be able to dig it out at this point. If you make a mess of the threads , and you probably will then get a Heli-coil kit and repair them. BTW don't heat the bolt if you plan on drilling them out this will harden them and make them almost impossible to drill. You can get small carbide die grinder bits at almost any builders supply like Home Depot in the Rotozip section. You may have noticed that I didn't even mention using a ease out. One of the worst things you can do is to break them or drill bits, taps, punches or anything else that's hardened off in the hole. We often have heads come in with all kinds of things broken off in the bolts. If a drill bit wont drill out a broken bolt it sure wont drill out another bit or tap. High carbide steel is real brittle and will snap in a heart beat.
Thanks for the info Donny, but I sent the heads to the machine shop this morning and had all 3 removed for $18.00... cant beat that and he did it while my son waited... Check my thread in the general discussion forum..
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