Timeserts

Legs

Legs

Hero member
Location
Adelaide Hills
Okay, got a dilemma; whilst re-torquing the head on my RGS (The Yellow Peril), the stud holding the left exhaust cam pedestal stripped. Not a problem I thought, I'll just put a helicoil in. When I pulled the stud I found that there were already two short helicoils in there that had given way. As the hole had already been drilled for helicoils and the threads stripped I investigated Timeserts and found you could get extra thick ones specially designed for repairing stripped helicoils.
There doesn't seem to be much 'meat' around the whole and was wondering if anybody had the misfortune of having to do this sort of repair.
Thanks in advance.
 
the larger ones are called Big Serts, I used two of them yesterday to repair 2 x 8mm cam stud holes that had been repaired previously with Helicoils and stripped again

There is enough room to fit the Big Serts in but when ordering make certain to order the 18mm long inserts, maximize the strength of the repair as much as possible

This poor 81 Jota cylinder head has had a hard life, all the cam stud holes have been repaired in the past, plus the engine has thrown a Conrod at some stage and upper engine case has stacks of welding repairs on it, etc

20221123_151110
 
it is possible, biggest issue is making certain you drill and tap the hole straight
seen a number of repairs done by hand where the stud winds up at a 15 degree angle, does not do cam block alignment much good
and swarf control is another issue with an assembled head

look at making a drill guide up, could use the flat face of the head as the basis of a guide, maybe piece of dressed hard wood with a suitable size hole drilled through it, use that to keep the drill square to the head
Good luck
 
Fix it once and fix it right. This SF with a bit of 8mm thread left in the hole, probably started with a wrecked heli-coil. No room for a time-sert now.
 

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I've just finished a triple head that required a handful of Timeserts for the cam bearing studs. Two threads had already been "repaired" with Helicoils, but the inserts had threaded their way too far down the bore. I fished them out and found their threads in the alloy were still quite sound. The Timesert tap cleaned these up nicely and I was able to install a regular Timesert.

piet
 
Taking your advice Red. Will only have one go at getting this right so engine out and head off is the go.
About time I had a peek inside anyway.
 
chrisk said:
Katie pie bro ….. whatever the fuck that means????
Click to expand...
Katie pie is what I call my wife when I want something, or if she is sad........shes a Katie,I leave the bro of it for her, shes not that keen on being called a bro, but otherwise if I say it to someone else it means "how are you bro.... "
 
Legs said:
Taking your advice Red. Will only have one go at getting this right so engine out and head off is the go.
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Wise, Legs. I was able to do one outer one using a Big-Sert - same cause as you, failed Helicoil; but I wouldn't risk it with any of the others.

(Helicoils - "Right shit cakes, them", to quote Keith Nairn. I'm still trying to get my head round 'shit cake'. Must be a Glaswegian thing ... :))
 
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