milling a helicoiled head
- Thread starter ewgoforth
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Anonymous
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Hi ewgoforth.
If it is just the alloy bulging and the helicoil is below the surface perhaps chamfer with a large drill bit.
Not my field but I believe milling could stuggle to accomodate the material change if the helicoil is encountered.
Over to you, millers.
Ta.
If it is just the alloy bulging and the helicoil is below the surface perhaps chamfer with a large drill bit.
Not my field but I believe milling could stuggle to accomodate the material change if the helicoil is encountered.
Over to you, millers.
Ta.
lcrken
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If the helicoil is close enough to the surface that the milling cutter will hit it, you need to remove it first, mill the head, and insert another helicoil. They are very easy to remove with the cheap v-shaped tool made for that purpose, and can probably also be removed with other similar tools, like a triangular scraper or some types of easy-out.
Ken
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Anonymous
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Hi ewgoforth.
Re your: "...Can this be done with steel helicoils in an aluminum head?..."
I reckon lcrken nailed it. Let us know how you get on.
Ta.
Re your: "...Can this be done with steel helicoils in an aluminum head?..."
I reckon lcrken nailed it. Let us know how you get on.
Ta.
I used a dremel sanding drum to get the edges of the hole almost perfectly flush with the surface. I didn't want to touch the gasket surface of the head. Hopefully this isn't the start of the helicoil pulling out. These studs are cycle thread, I believe on the sleeve nut side and I guess Whitworth or UNC where they thread into the head.
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ewgoforth said:
3/8 -16 Timeserts as recommended by Jim (and new studs)?
new-head-hardware-kit-t16488.html
lcrken
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I haven't been able to find any solid inserts in this size (3/8-20). A common mod I've done, and seen done by others, is to fit 3/8-16 inserts, which are commonly available, and use new studs with 3/8-16 on the cylinder head end and 3/8-24 on the nut end. I've made my own by cutting the heads off of good quality AN or NAS 3/8-24 bolts and cutting new 3/8-16 threads on the end, as well as just buying common Dorman exhaust studs in the appropriate length and shortening them on both ends to suit. I think Jim Comstock (comnoz) uses ARP studs, which are about as good as it gets. I'm sure he would be happy to sell you a set, or install them in your head for a reasonable fee. You can also have custom bronze thread inserts made to fit the 3/8-20 BSF studs. I believe Jim has also made those, but you'd have to check with him on that. Anyone with a decent thread cutting lathe and some care can make them. It's just kind of time consuming.
On the other hand, I've had pretty good luck with the helical inserts in 3/8-20 from Recoil, as long as you don't get carried away in over tightening the nuts. But I still prefer the solid inserts, just for the extra comfort factor.
Ken
On the other hand, I've had pretty good luck with the helical inserts in 3/8-20 from Recoil, as long as you don't get carried away in over tightening the nuts. But I still prefer the solid inserts, just for the extra comfort factor.
Ken
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