EJ head bolts - how many times can they be used?

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El_Freddo
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EJ head bolts - how many times can they be used?

Post by El_Freddo » Mon Jul 08, 2019 7:58 pm

As the title suggests, how many times can the EJ head bolts be used before it’s recommended that new ones be used?

Obviously if the bolts are rusty, heat stressed (overheated) or the threads are damaged they’re to be replaced.

I’ve got my sister’s EJ251 on the engine stand to replace the HGs (external coolant and oil leaks). This will be the second time I re-use the head bolts. The dude at the engine machine shop has me second guessing myself with a comment he made about the bolts stretching to a limit.

I’m not wanting to do this job again in another three or four years (or months if the bolts are dud)! This EJ251 is awesome to drive - I’ve got a soft spot for the EJ251 and probably the EJ253 too since having this 251 in the family.

Thoughts/opinions appreciated!

Cheers

Bennie
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Subyroo
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Re: EJ head bolts - how many times can they be used?

Post by Subyroo » Mon Jul 08, 2019 8:28 pm

Myself being pedantic, I'd use new head bolts to save having that nagging feeling in the back of my mind.

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TOONGA
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Re: EJ head bolts - how many times can they be used?

Post by TOONGA » Wed Jul 10, 2019 4:51 pm

Bennie the bolts are not stretch limited but they should be replaced if this is the second time they have been used.

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El_Freddo
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Re: EJ head bolts - how many times can they be used?

Post by El_Freddo » Thu Jul 11, 2019 4:30 pm

You mean the second time they’ve been reused?

I’ve reused these once already - and it turns out there’s two different types of bolts for the EJ251, the two inner bolts are different to the outer bolts.

I didn’t know this and had them where-ever they were randomly placed... no issues.

I’ll have to see if I can dig up the Subaru tech bulletin talking about the head bolt reuse. Problem is that I can’t remember where it was shared publicly.

Now that I have the heads back, I’m not in any rush for the head bolts as I’ve decided that I’ll replace the valve stem seals and lap the valves if needed.

The dude who shaved the heads gave me a good piece of advice - always retorque the cam retainer bolts once the headbolts are installed and up to torque. This could also explain why the EJ251 typically has a small leak from under the cam retainer plate, even though it’s sealed by silicone like three bond or that high torque application sealant.

Cheers

Bennie
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