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Cracked head story


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Hi,

Yeah doing a timing belt...

the car always leaked like a pig so I figured

that I would regasket the motor..... you know

new head gaskets etc.......

so I dropped off the heads to be resurfaced...

The old place I used to use went out of bussiness..

too bad...........

So I used the parts place that I use.....

Anyway, I get a call they are telling me

the heads are both cracked...... now...

mind you the car ran fine..... I had no complaints

about how the car ran..... It just was the timing

belt snapped.......

Any thoughts on this cracked head story...

I really don't want to buy new heads at 250.00

a pop........... Again, the car ran fine.....

Thanks, Micky:horse:

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This is normal. Ea82's don't fail headgaskets the same as newer engine. You could have probably left them be and been fine. Tell your mechanic to peen them down. If he doesn't trust his own work and liability for the work, find someone else that will.

 

You will find these cracks on 90% of pull-off heads from running engines.

 

However, cracks in the exhaust ports are bad. These don't occur naturally, but rather from excessive overheats and abuses.

 

There are TSB's about the heads. perhaps your machinist can look them up.

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Yeah, He is going to send them back to me

(from their machine shop to the part store)

I will look at them and probably send them

back to be resurfaced to look at........

I think he said, the crack goes in between from one to

the other

like I------E

dotted line representing the crack between the

I ntake and E xhaust.......

 

What is a TSB?

 

Also the valves were not removed... they are just doing

a resurface....(this place;they don't remove the valves)

so he didn't look inside the port... crack is between valves

in combustion chamber part of head.

thanks

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Geez. I got this smartphone but

It hasn't made me smarter. There

I was stAring at those cracked heads

At the parts store. And I didn't get

A picture.

So will describe. Cracks are between

Valves starting in the casted area the

Cracks proceed towards the exhaust

Valves down towards the valves and

Give an unclear impression that they

Go toward(through) the seat

A picture says 1000 words.

Sorry for the lack of a picture

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Between valve cracks are NORMAL. All EA82 heads have these. Subaru has issued a TSB to ignore them.

 

You can easily resurface the heads yourself and rent a valve spring compressor to take out the valves and install new seals. An inexpensive kit to lap the valves smooth is also a good idea. You don't need a machine shop to do these things and in any case they clearly have no experience with these heads.

 

GD

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post-3422-136027653242_thumb.jpg

 

Thanks for all the input on this...

this is a pic on one of the cracks

in the combustion area on the head...

they are all like this.. in the middle

like previously mentioned...... Just

figured a picture is best for everybody

to see...

So resurfacing my self...... I want

the head to be true removed of any

warping..... How can this be done....

without a milling machine ?

Where do you recomend I get a

kit for lapping the valves.... or if

you could just provide me with a link

to such a kit..........

MilesFox.... wondering if you could explain

the peening on the gaskets? What do you

mean ?

 

Thanks, Micky

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I meant peening the crack itself. just get a small pointed punch and sort of tap down the edges of the crack to smoosh it together.

 

The only potential for compromise with the crack is the valve seats. I have seen valve seats pop out. you can stake the side of the valve seat near the crack to prevent this. This is what peening the crack would be.

 

You made that crack sound a lot worse than the picture. I have seen wider cracks on running cars.

 

If you want my advice, (or my opinion on your specific operation) don't bother resurfacing the head. I never do. If the head is just a pull off on a non-cooked engine, it will be good to go. YOu can if you want to yourself, but otherwise, save yourself the expense. ($)

 

There is a slight concavity across the head naturally that gets squeezed down by torque. The heads slide on their gaskets by design with different expansion rates to the block and intake.(graphite faced gaskets). some .002 difference in flatness is within spec

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Your cracks are 100% normal. Don't do anything with them. Just surface the heads, lap the valves, and change the stem seals.

 

My post on head surfacing:

http://www.ultimatesubaru.org/forum/showthread.php?t=126868&highlight=apocalyptic

 

http://www.amazon.com/Permatex-80037-Valve-Grinding-Compound/dp/B000FW4MFC/ref=sr_1_31?ie=UTF8&qid=1328809553&sr=8-31

 

(look at the "frequently bought together" listing for the tool, compound, and prussian blue to check your surfaces).

 

GD

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Cool Thanks !

GenDis

So I am going to collect my items to resurface

at home... I got a nice butcher block work bench....

I need a piece of glass...

5/16 X ? X ? by what do you recommend...

 

I am assuming that your sheet of 220 wet dry paper is

8.5 X 11.... so when you glue the paper down(on the glass).....

are you gluing two sheets next to each other,

thus getting a 17 X 11 sanding surface?

And what kind of stroke do you use while sliding

the head on the sand paper?

 

Are you (represent with clock as direction)

 

moving/sliding the head from the center position to say

10 oclock and then back to center position

and then moving/sliding the head to say

2 oclock? and then back to center position......

 

repeat process till completed?

 

MilesFox

with the peening

 

I meant peening the crack itself. just get a small pointed punch and sort of tap down the edges of the crack to smoosh it together.

Ok, I can dig it...

 

The only potential for compromise with the crack is the valve seats. I have seen valve seats pop out. you can stake the side of the valve seat near the crack to prevent this. This is what peening the crack would be.

So what if it look like the crack goes through the seat?

I cant really determine this cause the valves are still in.....

I would peen it right before the seat?

I get the idea with peening generally speaking....

If you had a crack in a concrete wall.... one

may drill the crack at its end point then fill the wall.....

similar concept...

 

Again much thanks, Micky

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