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Engine basics => Engine set up tips => Topic started by: FLOYD CARTER on March 05, 2014, 02:54:00 PM

Title: Stripped thread repair
Post by: FLOYD CARTER on March 05, 2014, 02:54:00 PM
I recently had occasion to repair stripped cylinder head threads for 1/4-32 spark plug (or glo plug--same thread).

The repair kit is RECOIL #34040-32 and it contains all tools and supplies necessary: drill, tap, insert tool and a dozen "heli-coil" inserts.

I practiced on a scrap piece of aluminum, but practice wasn't necessary.  Everything worked exactly as desired.

For engines still in production, it's easier to order a new cylinder head, but for others.....

Floyd
Title: Re: Stripped thread repair
Post by: Jim Kraft on March 05, 2014, 05:53:34 PM
That looks pretty neat Floyd. I sent a few old sparker heads to Clarence Lee a few years ago for just that fix. I think he was doing them for about 6 or 8 dollars ea. post paid back then. Probably been longer than I thought. LOL
Title: Re: Stripped thread repair
Post by: FLOYD CARTER on March 07, 2014, 11:34:38 AM
This is an Atwood Champion 60.  No parts available, so a repair is the only option.  It sure worked slick!

Floyd
Title: Re: Stripped thread repair
Post by: Chad Hill on May 05, 2014, 08:02:51 AM
Hello Floyd,

Can you provide a link to ordering this kit? I've done a web search but could not find one. Thanks, Chad
Title: Re: Stripped thread repair
Post by: Brett Buck on May 05, 2014, 09:16:57 AM
This is an Atwood Champion 60.  No parts available, so a repair is the only option.  It sure worked slick!

    You are probably aware of this but many others might not. In most cases on our satellites, where things have to be screwed to aluminum (2024, mostly), we don't even bother with the intermediate step. Inserts are used right from the start, in new manufacture.

    Brett
Title: Re: Stripped thread repair
Post by: Tim Wescott on May 05, 2014, 09:58:06 AM
    You are probably aware of this but many others might not. In most cases on our satellites, where things have to be screwed to aluminum (2024, mostly), we don't even bother with the intermediate step. Inserts are used right from the start, in new manufacture.

The company I worked for would assess the hole for necessary strength and frequency of use -- if it was going to go through many assembly/disassembly cycles, or if it was going to be stressed heavily, it'd get an insert.

The inserts we used weren't quite heli-coils: they're designed for use from day 1, not to be put into a possibly tight space on existing equipment, so they didn't have the same design constraints as heli-coils do.  AFAIK, they worked great.
Title: Re: Stripped thread repair
Post by: bob whitney on May 08, 2014, 10:38:14 PM
just make sure the insert is flush with the inside of the head when finished or it can cause a hot spot and pri ignite causing the engine to run hot
Title: Re: Stripped thread repair
Post by: Jay on September 21, 2014, 09:16:31 PM
How do I contact Clarence Lee?  He is not listed in the membership unless he uses a different name.
Thanks

Jay
Title: Re: Stripped thread repair
Post by: Don Hutchinson AMA5402 on September 22, 2014, 05:52:21 PM
Clarence has an ad on page 169 of the September Model Aviation magazine. Prices, address and phone number.
Title: Re: Stripped thread repair
Post by: MikeCoulombe on September 22, 2014, 07:55:25 PM
I just ordered from these guys,
http://www.rivetsinstock.com/thread-repair-kits.html
I recently stripped the plug from my Saito 150.
Title: Re: Stripped thread repair
Post by: BillLee on September 23, 2014, 04:47:14 AM
I just ordered from these guys,
http://www.rivetsinstock.com/thread-repair-kits.html
I recently stripped the plug from my Saito 150.

Still begs the question: where to get the tool for 1/4-32 threads. I looked at this site and did not see any UNEF thread sizes listed, on the website nor on the catalog.
Title: Re: Stripped thread repair
Post by: MikeCoulombe on September 23, 2014, 05:24:12 AM
It is almost at the bottom of the page under "special size thread repair kits"
Part # RC-34040-32
Title: Re: Stripped thread repair
Post by: BillLee on September 23, 2014, 10:04:10 PM
It is almost at the bottom of the page under "special size thread repair kits"
Part # RC-34040-32
Thanks! Easy to overlook that one.