2O2F>>>I'm a fixer , not a " tech" >>> If you wanna be a bit tech-ier, you could always use expanding concrete drop-in anchor nuts to help relieve any Farmer Fix anxieties.
I sort of like this idea........ but I think I'd feel better placing bushings in the wood on the 2 good, outer studs and a nut to guide the stepped-up thread tap. JB Weld all 3 metal pieces with the wooden jig riding on the studs so all 3 guide bushings will turn out correctly spaced, square with each other, and no wiggles. There will be little to no stress on the jig but if you have other material that you feel more confident in using, go for it.
2O2F>>>Wtf does putting in a helicoil have to do with expansion anchors ?>>> Hmmm. I'm gonna guess both might fix a stripped thread in an aluminum cyl head. Did I guess right?
I've done a bunch of these fixes on aircraft over the years. I've gotten pretty good at running a 90 degree die grinder with a mirror. One thing that helps a bunch is if you can use a round tip 1/8" rotary file to create a dimple as close to center as you can, your drill bit will tend to stay on course. Next step, I don't expect you'll run out and buy a 90 degree aviation drill and threaded bits, but they do allow access in some very tight spaces. I have run drill bits in die grinder collets in a pinch, but the speed kills the bits. Good luck!
I don't know , I kinda like Husky tools , their fastener selections , crimp connectors , ptfe paste and more !
I’d be concerned about cracking the head driving something like that in. Some of those aluminum heads can get thin in areas around pushrod tubes, cooling jackets etc…..
sgtlethargic >>I don't see how a lag fastener is any riskier for cracking the head than tapping for and installing a larger diameter fastener. >>> In theory, a tap is supposed to cut a thread & pocket cut debris in flute grooves. Thus less risk in theory. In practice however, aluminum often sticks to tap threads. Galling. So you're probably right. Self-tapping fluted lags are also available for those who worry about such things.
if its a Pro comp sbc head, sure, take a chance and tap away with a drop in anchor or lag bolt. if its a Kaase Boss 429 head I'd have that head already off the engine for a proper repair. For me it comes down to what you have to lose if you screw up.
sgtlethargic>>>What's your hurry? Good replies are still coming in. >>> Yeah. Never do now what you can put off indefinitely.
You can do a proper Heli-coil on the car just as good as on the bench. Like others have said, with a piece of thick plate as a guide, pre drilled using the hole pattern from the manifold gasket. Bolt the plate on to the next hole. You can get shorter drills if needed and I’ve even cut drill lengths down to fit. I once repaired an oil cooler on a T-56 Allison in a C-130 using a shortened drill and some persistence. Let us know how you make out. Good luck.
If it's a certain G.M. head Dorman offers some easy repair brackets that work well without drilling. I've used this one and it worked well.
Whatever is done other than welding the hole shut and redrilling to size, the hole is going to be enlarged somewhat. To put an expanding lag fastener in the head will require the hole be even bigger than it will be with just using a heli-coil or retapping to the next larger size. If you drill it out far enough to hold a lag, and then it doesn't work right.........what next? Do it right and do it only once.
I think the concept behind any quick & dirty FarmerFixes is to use the existing stripped out hole as-is. IOW, don't try to enlarge nor drill it out. A smaller diameter fastener than original should be able to satisfactorily snug up the manifold to the head.
Seriously? Lag bolts belong embedded in wood. Screwing a steel bolt into an aluminum head will distort or damage what remains of the hole. Not to mention the corrosive reaction that begins.No fixing it then. As others have said it's a 1 shot deal. Can't believe the number of lazy, ineffective ways posited in favor of doing it correctly.
I don't think you should have to drill it. If the threads are pulled out and you us a helicoil kit you will see that the drill bit only takes the threads out of a already drilled and tap hole. And the tap will cut the threads for the helicol, I have put many helicol into heads at work with striped out 3/8 stander thread and we don't have to drill the hole we just use the helicol tap and insert the heicol. Just make sure that you tap the hole stright, good luck on this.
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