Stripped SZ-H. Argh.

[ChrisLaFollette]

Me and my friggen gorilla grip tightening skills... stripped a headbolt. What are my options?

Could I just stick the crank, rod, sleeve/piston into the C-Spec case I have and run it like that? If that would work would the C-Spec case hold up to the 15,700 rpm the SZ-H "stuff" is suppose to make its most power at? Probably sounds like a silly question but just making sure. Dont need the engine blowing up if I go that route, if its possible.

[flyinfool]

It is a bit of an investment but a HeliCoil kit will fix gorilla grip issues or most other damaged thread issues.
The kit will cost as much as a new case but then you will have it for future repairs.
With a HeliCoil you drill out the old stripped thread, tap the hole using a special tap, insert a HeliCoil thread insert using a supplied tool, remove the drive tang with the supplied tool and end up with threads that are stronger and better than new.

[DavidH]

http://www.ronlund.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=heli&Product_Code=TORKIT

Only tool needed for engines. If you ever use one, you will be really surprised how very little pressure is needed to torque the bolts properly. A 3mm bolt only torques to 12-14 inch ozs.

David

[Ivan]

One thing to watch out for when you use threaded inserts is that you get the tap PAST the end of the insert. Taps haev a tapered nose, and if that taper is not deeper than the insert, the screw will bind, cause the threads to strip, ruin the insert and most likely the hole as well. If you don't haev room, get a bottoming tap. Bottoming taps don't have the long taper, and are pretty flat on the nose, sothey only finish the threads cut by a regular tap. Finding a bottoming tap for a helicoil may be a problem, but you can buy another regular tap and make a sufficient bottoming tap with the dremel tool.

Personally I would buy a new case. I don't care for inserts. I guess there would be the option of finding some one really good with a tig and filling the hole and re drilling and tapping it again. Not sure how feasable that would be though.

On a head bolt on an engine, I use a touch of light oil (usually found drippig off one of my nasty models :mrgreen: ) and tighten them to a little bit more than snug. Then I re tighten them when the engine is still worm after running, firm, but not terribly tight. Same method with ehaust bolts on mufflers. Using this method, the headbolts will be as tight as needed, and when removal time comes, they will be tight enough to make a snapping sound as they break loose, and I have never had a head bol come loose. Muffler bolts are cantankerous and the only thing i have found that keeps them seated long term is high temp loctite (yeah they make it.)

I am sorry to hear of your misfortune. I hate learning lessons the hard way. :arggg:

[ChrisLaFollette]

Good news. Found some shouldered bolts longer than needed but cut them down to size. I had to put two washers under the head of each bolt (between the fins) to space them correctly so the shouldered part wasnt trying to go into the holes, but now I got bolts long enough to go to the bottom of each hole in the head so now I got threads in the partial stripped hole and the rest of the holes are fulla bolt. So now they are all equal and plenty snug in the engine. Might be a good thing I stripped it, now I have some extra insurance. I dont think that head is blowing off anytime soon, or ever for that matter unless I take the bolts out. Ehh anyways.. im happy. :D

[WayneBrown]

im happy. :D
that didn't take much... LMAO
glad to hear ya got it fixed, now come up one weekend so we can fly.

[ChrisLaFollette]

You come down HERE, mr wanna see bling face. :lol: Look up marianna. Im 20 miles away.

[RC-Bearings]

Go here and enter "torque" in the search:

https://www.micro-tools.com/store/mainframe2.aspx