Head & head gasket questions

[jellywrestler]

the threads in the cylinder head are stripped and 2x have already been previously helicoiled (last year ) by a engine reconditioner
which lasted 10 kms

so why did they fail, did you torque them correctly?

[Grumph]

The difference between a 10 and 12 mm bolt is an extra one mm in the bolts radius.

Is that extra one mm enough safe steel to thread a bolt hole .. after a helicoil has been stripped from the same location ... ???

No - but I'd put a 12mm helicoil in there anyway - and the tap drill size for a 12mm thread helicoil is 12mm....

And make it a long series one while you're at it.

[hayd3n]

so why did they fail, did you torque them correctly?

when i originally removed the head last year the head bolts were so tight it removed a hell of a lot of aluminium
, i believe the helicoil diddnt have much to bind to,
the new 12mm threads in the cylinder are a hell of a lot longer than the old one as the threads were recessed down about 25mm, below the dowels , so they only had 20/25 mm of grab

[hayd3n]

the heli coil drill size is 10.5 which is also the same size i have used to tap the new 12mm x 1.5 bolts , however i have a lot more depth in the thread now

[jellywrestler]

the threads in the cylinder head are stripped and 2x have already been previously helicoiled (last year ) by a engine reconditioner
which lasted 10 kms

when i originally removed the head last year the head bolts were so tight it removed a hell of a lot of aluminium
, i believe the helicoil diddnt have much to bind to,

seems like you know better than your engine reconditioner, i'd get a better one of the two

[hayd3n]

seems like you know better than your engine reconditioner, i'd get a better one of the two

well you dont know unless you try these things / hes a gc and has given me free head bolts , and brush honed the cylinder

the gasket itself is cheep,

other work i have had done has been fantastic

[tigertim20]

And a reason not to change to the double sized studs would be ... ???

Quick and easy and you don't fuck gaskets.

double sided bolts mentioned by fjrider could be a good solution - but with them not having a head on them can make them a right cunt to get out later if you need to do other work for some reason or whatever.

I cant see it being difficult to sort out the locating pins, it doesnt matter where they are really does it? even if you drill new holes and reuses the same pins you have now or swap out for roll pins or similar?

[hayd3n]

double sided bolts mentioned by fjrider could be a good solution - but with them not having a head on them can make them a right cunt to get out later if you need to do other work for some reason or whatever.

I cant see it being difficult to sort out the locating pins, it doesnt matter where they are really does it? even if you drill new holes and reuses the same pins you have now or swap out for roll pins or similar?

im thinking if i made studs there may not be enough clearence to refit the head its a tight squeeze already,
the dowels are to small as the headbolts go thru the centre of them.
i am looking at making /buying new ones, most likely make them

[FJRider]

double sided bolts mentioned by fjrider could be a good solution - but with them not having a head on them can make them a right cunt to get out later if you need to do other work for some reason or whatever.

I cant see it being difficult to sort out the locating pins, it doesnt matter where they are really does it? even if you drill new holes and reuses the same pins you have now or swap out for roll pins or similar?

In my younger years I rebuilt the top end on an old XL250. The studs were buggered and new ones were helicoiled in. Using nuts on the studs removed the need to endanger the helicoils if head removal was later needed for some reason.

It lasted for years ... until I found a deep water hole. As far as I know ... the bike is still in that same hole.

[DrunkenMistake]

im thinking if i made studs there may not be enough clearence to refit the head its a tight squeeze already,
the dowels are to small as the headbolts go thru the centre of them.
i am looking at making /buying new ones, most likely make them

If for whatever reason you do use studs and need to get them back out gimmie a yell we have stud removers at work, shouldnt fuck the studs but sometimes they can.

[Akzle]

If for whatever reason you do use studs and need to get them back out gimmie a yell we have stud removers at work, shouldnt fuck the studs but sometimes they can.

wtf.
Just lock two nuts against each other on the threads you've got and wind out using the bottom one.

[Drew]

wtf.
Just lock two nuts against each other on the threads you've got and wind out using the bottom one.

Doesn't always work on seized studs. Extreem measures, weld a nut to them...Always let it cool down before attempting to wind it out.

[Akzle]

Doesn't always work on seized studs. Extreem measures, weld a nut to them...Always let it cool down before attempting to wind it out.

or use heat/oil/impact driver, to unseize it.

(i've yet to meet a bolt i can't fuck up)

[hayd3n]

scored some dowels today 14mm od

[Tarded]

I dont like helicoils. Glorified bloody springs.

have a look at Wurth timeserts - a much better product.

I dont work for them by the by but I did years ago.

http://www.wurth.co.nz/

I was a mechanic for years too and timeserts are the shit.

I hate fixing shit twice so would rather spend the coin once.

Up to you.