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Helicoiling cylinder head. Some advice needed

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peter0991
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Helicoiling cylinder head. Some advice needed

Postby peter0991 » Mon Jan 13, 2014 11:29 pm

Hey guys,

Thought I'd make a start on fixing my car after the last season. One of the exhaust manifold studs has stripped the thread in the cylinder head. My immediate thought was to helicoil it. But I am pretty unfamiliar with the process so I wanted to find out if anyone on here has done it.

One of my first questions is: What is the thread size and pitch on the manifold studs? I know that the part number is 90116-10146, but I want to order some helicoils and cant seem to find the stud specs anywhere. Can anyone help?

Is there anything I should be careful of while drilling out and tapping the holes for the helicoils in the head? Any oil channels or cooling jacket perhaps?

I have decided to pull the cylinder head off to make my life easier. Can i reassemble it using the old head gasket? Or would that need to be replaced as well? Would the head bolts need replacing?

Obviously would need a new exhaust manifold gasket as well.

Have I missed anything out?

Any help would be appreciated :D
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mike_01
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Re: Helicoiling cylinder head. Some advice needed

Postby mike_01 » Tue Jan 14, 2014 11:47 am

get good quality coils as the cheap ones fall apart very easy and can be an arse to get in other than that take your time doing it and buy new drills if needed :wink:

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peter0991
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Re: Helicoiling cylinder head. Some advice needed

Postby peter0991 » Tue Jan 14, 2014 2:02 pm

Cheers dude :wink: Need to know what the thread specs are first. Are there other solutions as well as helicoiling? Like those solid inserts?
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twiglett-RS200
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Re: Helicoiling cylinder head. Some advice needed

Postby twiglett-RS200 » Tue Jan 14, 2014 2:06 pm

If you're taking the head off you might as well stack two gaskets or get a thicker one to lower the compression.

Around the studs in the head is pretty safe.
Toyota don't usually put anything important in such close proximity to fixing studs, especially on the exhaust side.

I have a pack of manifold studs for mine.
If it helps they are the same as the ones that were on my s14 (Sr20)

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peter0991
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Re: Helicoiling cylinder head. Some advice needed

Postby peter0991 » Tue Jan 14, 2014 2:16 pm

Thats the plan dude ;) More powers are definitely needed :D

Ah, that should make life easier! Ill find out what specs the SR20 studs are. My guess would be that they are M10, but I want to be sure lol
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twiglett-RS200
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Re: Helicoiling cylinder head. Some advice needed

Postby twiglett-RS200 » Tue Jan 14, 2014 7:39 pm

Want me to find out at work?
I'm being really forgetful recently so send me a message on fb and I'll find out exactly what the altezza ones are.
I can get all the gaskets you need at better than trade price but postage would be tricky.

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peter0991
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Re: Helicoiling cylinder head. Some advice needed

Postby peter0991 » Wed Jan 15, 2014 8:01 am

Sweet dude! Il drop you a message now. Can you get thicker gaskets to lower the compression as well, or just the OEM ones?
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mike_01
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Re: Helicoiling cylinder head. Some advice needed

Postby mike_01 » Wed Jan 15, 2014 11:49 am

m10 x 1.25 thread
yes you can get thicker gaskets hks do them I know for sure they do a range of thickness

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peter0991
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Re: Helicoiling cylinder head. Some advice needed

Postby peter0991 » Wed Jan 15, 2014 11:53 am

Yup, I know HKS do them. But would be good to see if there was an alternative closer to home :lol: Cheers man. Gonna look up some coils now.
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peter0991
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Re: Helicoiling cylinder head. Some advice needed

Postby peter0991 » Wed Jan 15, 2014 12:32 pm

mike_01 wrote:get good quality coils as the cheap ones fall apart very easy and can be an arse to get in other than that take your time doing it and buy new drills if needed :wink:


Any particular brand?
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