Bad valve job. Machine shop killed lifter clearances.

Josey Wales · 07-29-2008, 01:52 AM

I'm having a hang-up with a 255 '06 wrx build right now and could use some insight from some more experienced builders. And my math double checked.

Long story made short... Stock piston blew apart from pre-ignition. The piston kissed the head bending 3 valves and the plug. Head was sent off to the machine shop to be welded and rebuilt. They went ahead and did a full valve job without being told too, and cut the seats pretty deep & did nothing to compensate

. The clearances are completely shot now.

Before I post up a chart of measurements... what should the proper lash settings be for 06+ avcs wrx?

I went ahead and calculated what size lifters I need if they are indeed .008/.010". If those are the proper clearances, even the 468 lifter won't work.

* Registered users of the site do not see these ads.

Josey Wales · 07-29-2008, 02:09 AM

Here is what I got...

USED = What bucket was used to measure (for reference)

A ground down spare was measured at 4.641 and used for reference when measuring the intake since those were extremely tight.

*Yellow represents cylinders. Rows above are intake, below are exhaust.

Storm · 07-29-2008, 08:19 AM

Something tells me this conversation should be with the machinist.......

Jay

Homemade WRX · 07-29-2008, 10:13 AM

You need to bring this up with the shop that FUBAR'ed the seats.
I'd push to have them put in new seats and re-do the work as the head is useless unless you custom machine the buckets or re-seat the head. Re-seating would be the better way to go and can allow you to open the throat and port too!

sluflyer06 · 07-29-2008, 12:46 PM

Turns out subaru makes lifters down to 438.

Homemade WRX · 07-29-2008, 01:25 PM

Quote:

Originally Posted by sluflyer06

Turns out subaru makes lifters down to 438.

I just re-read it. I thought he said 438. I need to get more sleep

BallPeenHamr · 07-29-2008, 02:06 PM

Be aware that welding the head might permanently soften the aluminum. If the combustion chamber was welded near the seats, the interference fit of the seat inserts might loose it's press and could possibly fall right out of the head when engine reaches temp for the first time. Then you'll be right where you started again..

A soft head can even make it so that your head bolts won't torque up because the head just squishes as you tighten the fastener. You could fail head gaskets too.

I would definitely seek the advise of an experienced engine builder who can test the hardness of the head b/c you might be working with a head that should be deemed srcap.

A new B25, V25B, and W25 Subie head should have a hardness of around 92 on the Rockwell "E" scale. I wouldn't run anything below 80.

sluflyer06 · 07-29-2008, 02:22 PM

Quote:

Originally Posted by BallPeenHamr

Be aware that welding the head might permanently soften the aluminum. If the combustion chamber was welded near the seats, the interference fit of the seat inserts might loose it's press and could possibly fall right out of the head when engine reaches temp for the first time. Then you'll be right where you started again..

A soft head can even make it so that your head bolts won't torque up because the head just squishes as you tighten the fastener. You could fail head gaskets too.

I would definitely seek the advise of an experienced engine builder who can test the hardness of the head b/c you might be working with a head that should be deemed srcap.

A new B25, V25B, and W25 Subie head should have a hardness of around 92 on the Rockwell "E" scale. I wouldn't run anything below 80.

no welding was done. It ended up being un-needed and unadvised by the machinist.

bloopsta26 · 07-29-2008, 03:55 PM

wow this is funny. seams like machine shops are having problems doing head work for subies...cause the place who did mine screwed up too

Turbo_Mike · 07-29-2008, 04:46 PM

honestly, for a non subaru head, that was the right thing to do. the machine shop was fixing the damage, which probably also consisted of the valve seats being slightly damaged. a valve job fixes that. they probably honestly didnt know what it would change the cam tolerances.

sluflyer06 · 07-29-2008, 05:09 PM

Quote:

Originally Posted by Turbo_Mike

honestly, for a non subaru head, that was the right thing to do. the machine shop was fixing the damage, which probably also consisted of the valve seats being slightly damaged. a valve job fixes that. they probably honestly didnt know what it would change the cam tolerances.

and as a machine shop with extensive experience in engine building you'd think if they didn't know the consequences of an action that they would check before machining it.

You can always remove more material but you can never add it back.

When you scroll through the lifter's in the shop manual the #'s go from 468 to 527 but then without pause reset back to 438 to 466 and then again resume at 529 and top out at 565. Its completely illogical but thats Subaru for you.

axelthrasher · 07-29-2008, 05:32 PM

Which machine shop were you working with on this?

Josey Wales · 07-29-2008, 08:20 PM

Quote:

Originally Posted by Turbo_Mike

honestly, for a non subaru head, that was the right thing to do. the machine shop was fixing the damage, which probably also consisted of the valve seats being slightly damaged. a valve job fixes that. they probably honestly didnt know what it would change the cam tolerances.

The seats were not damaged, and only 3 valves were replaced with OE parts. A simple disassembly, repair, tank job, and reassembly would have sufficed. Not too mention the amount of material they removed. They claimed .001 was cut away, but the numbers don't lie.

Quote:

Originally Posted by axelthrasher

Which machine shop were you working with on this?

AES out by O'Hare. I wouldn't recommend them to anyone. I handed them 2 completely assembled heads. I received 2 boxes of loose parts rolling around inside. They didn't even wrap up the camshafts.

Meh... either way we have a solution.

bluescoobywagon · 07-30-2008, 02:55 PM

This is the reason I decided to send my heads to a known Subaru engine builder as there are just too many horror stories about crappy machine work.

It is possible to cut down the valve stems to get the lifters back in spec...

charliew · 08-19-2008, 11:01 AM

Cutting the stems seems to be a normal repair. We ground the inside of the buckets to fit. I don't know if they will be too soft but we tried it anyway as I couldn't figger out how to precisely cut the stems. The valve train clearances haven't gotten any louder so far.

sluflyer06 · 08-19-2008, 01:04 PM

Quote:

Originally Posted by charliew

Cutting the stems seems to be a normal repair. We ground the inside of the buckets to fit. I don't know if they will be too soft but we tried it anyway as I couldn't figger out how to precisely cut the stems. The valve train clearances haven't gotten any louder so far.

Everything with the clearances was sorted out by using the correct buckets. I was told u could cut the stems but only very very little or you will cut off the hardened portion of the tip.

Storm · 08-19-2008, 04:45 PM

Glad it's working out for you. You'll be back up and running in no time!

Jay

kellygnsd · 08-19-2008, 05:48 PM

Can I ask how much the shop charged for the repair. If you only paid for the valve repair/replacement I wouldn't expect them to set the lash too. Anytime you replace a valve even with a stock one you will have to adjust lash most of the time due to the difference in length between the valves.

sluflyer06 · 08-19-2008, 06:50 PM

Quote:

Originally Posted by kellygnsd

Can I ask how much the shop charged for the repair. If you only paid for the valve repair/replacement I wouldn't expect them to set the lash too. Anytime you replace a valve even with a stock one you will have to adjust lash most of the time due to the difference in length between the valves.

Only 4 valves were replaced. I do realize those 4 could be different but without cutting teh seats the chances are good you would only need a couple and the rest you could swap around to get into spec.

2nd. when the heads were dropped off they were asked to simply repair, clean, and have them ready to bolt back on when they were ready.

I don't have the invoice in front of me, they didn't even charge to clean up/repair the combustion chamber but the "competition valve job"(whatever that means) was $250. Then there were charges for disassembly, reassembly, etc. I can't remember everything that was on there...I believe the final bill was about $650 or so minus 50-60 for my flywheel.

robbieshonda · 08-19-2008, 09:30 PM

When I do heads For Subarus or Others, If they have valve damage I cut the seat to be safe, you might not be able to se an oblonged seat ect.

My workflow consists of disassembley, hot tanking/cleaning, checking all of the valves and the rest of the head magnaflux ect ( if needed) re surface the head, cut the valve seats, cut the valves if needed, adjust valve lash( machine the buckets and or the valve, Depending on the machine shop you take it too they should have all of the tools to to the job right but you should ask the machinest if he has worked on subarus( in this case) beforehand.

Glad you got your heads back together.

a Competition valve job ussually has a 3 or more angles. Some heads flow better with certain angles, and bowl blending or backcutting ect.

07-29-2008, 01:52 AM	#1
Josey Wales Scooby Newbie Member#: 102682 Join Date: Dec 2005 Location: Wood Berry Vehicle: i <3 gains '13 848 '09 696	Bad valve job. Machine shop killed lifter clearances. I'm having a hang-up with a 255 '06 wrx build right now and could use some insight from some more experienced builders. And my math double checked. Long story made short... Stock piston blew apart from pre-ignition. The piston kissed the head bending 3 valves and the plug. Head was sent off to the machine shop to be welded and rebuilt. They went ahead and did a full valve job without being told too, and cut the seats pretty deep & did nothing to compensate . The clearances are completely shot now. Before I post up a chart of measurements... what should the proper lash settings be for 06+ avcs wrx? I went ahead and calculated what size lifters I need if they are indeed .008/.010". If those are the proper clearances, even the 468 lifter won't work. * Registered users of the site do not see these ads.

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07-29-2008, 02:09 AM	#2
Josey Wales Scooby Newbie Member#: 102682 Join Date: Dec 2005 Location: Wood Berry Vehicle: i <3 gains '13 848 '09 696	Here is what I got... USED = What bucket was used to measure (for reference) A ground down spare was measured at 4.641 and used for reference when measuring the intake since those were extremely tight. *Yellow represents cylinders. Rows above are intake, below are exhaust.

07-29-2008, 08:19 AM	#3
Storm Scooby Guru Member#: 5218 Join Date: Mar 2001 Chapter/Region: MWSOC Location: SAUL'S Motorsports Vehicle: 96L Most Over- Developed Beater	Something tells me this conversation should be with the machinist....... Jay

07-29-2008, 10:13 AM	#4
Homemade WRX Scooby Guru Member#: 33782 Join Date: Mar 2003 Chapter/Region: MAIC Location: 3MI Racing LLC Vehicle: 96 bastard child search FIRST, then PM!!!	You need to bring this up with the shop that FUBAR'ed the seats. I'd push to have them put in new seats and re-do the work as the head is useless unless you custom machine the buckets or re-seat the head. Re-seating would be the better way to go and can allow you to open the throat and port too!

07-29-2008, 12:46 PM	#5
sluflyer06 Scooby Specialist Member#: 111641 Join Date: Apr 2006 Chapter/Region: MWSOC Location: St. Louis, MO Vehicle: 08 BMW 135i MSport tuned/full exhaust/intake	Turns out subaru makes lifters down to 438.

07-29-2008, 02:06 PM	#7
BallPeenHamr Scooby Newbie Member#: 126526 Join Date: Sep 2006 Chapter/Region: SCIC Location: Long Beach Vehicle: 2007 STi Limited #339 UGM	Be aware that welding the head might permanently soften the aluminum. If the combustion chamber was welded near the seats, the interference fit of the seat inserts might loose it's press and could possibly fall right out of the head when engine reaches temp for the first time. Then you'll be right where you started again.. A soft head can even make it so that your head bolts won't torque up because the head just squishes as you tighten the fastener. You could fail head gaskets too. I would definitely seek the advise of an experienced engine builder who can test the hardness of the head b/c you might be working with a head that should be deemed srcap. A new B25, V25B, and W25 Subie head should have a hardness of around 92 on the Rockwell "E" scale. I wouldn't run anything below 80.

07-29-2008, 03:55 PM	#9
bloopsta26 Scooby Specialist Member#: 131371 Join Date: Nov 2006 Chapter/Region: TXIC Location: Belvitucky Vehicle: 05 buy my parts so i can get my sti running	wow this is funny. seams like machine shops are having problems doing head work for subies...cause the place who did mine screwed up too

07-29-2008, 04:46 PM	#10
Turbo_Mike Scooby Newbie Member#: 130276 Join Date: Oct 2006 Chapter/Region: NESIC Location: Dudley, MA Vehicle: 2004 Pontiac GTO LS1 T56 RWD	honestly, for a non subaru head, that was the right thing to do. the machine shop was fixing the damage, which probably also consisted of the valve seats being slightly damaged. a valve job fixes that. they probably honestly didnt know what it would change the cam tolerances.

07-29-2008, 05:32 PM	#12
axelthrasher Scooby Specialist Member#: 144779 Join Date: Mar 2007 Chapter/Region: MWSOC Location: In the land up over Vehicle: 200X ZOMG a car 100% crabon fibre girlfrendorz	Which machine shop were you working with on this?

07-30-2008, 02:55 PM	#14
bluescoobywagon Scooby Specialist Member#: 14911 Join Date: Feb 2002 Chapter/Region: MWSOC Location: The land of E85 Vehicle: Not A Wagon! 2011 WRX - 285s on 18x10s	This is the reason I decided to send my heads to a known Subaru engine builder as there are just too many horror stories about crappy machine work. It is possible to cut down the valve stems to get the lifters back in spec...

08-19-2008, 11:01 AM	#15
charliew Scooby Specialist Member#: 125304 Join Date: Sep 2006 Location: Crawford, TX.	Cutting the stems seems to be a normal repair. We ground the inside of the buckets to fit. I don't know if they will be too soft but we tried it anyway as I couldn't figger out how to precisely cut the stems. The valve train clearances haven't gotten any louder so far.

08-19-2008, 04:45 PM	#17
Storm Scooby Guru Member#: 5218 Join Date: Mar 2001 Chapter/Region: MWSOC Location: SAUL'S Motorsports Vehicle: 96L Most Over- Developed Beater	Glad it's working out for you. You'll be back up and running in no time! Jay

08-19-2008, 05:48 PM	#18
kellygnsd Scooby Guru Member#: 32669 Join Date: Feb 2003 Chapter/Region: SCIC Location: Rancho C Vehicle: 2007 FR TS EFR 7670 LINK G4 hybrid STi	Can I ask how much the shop charged for the repair. If you only paid for the valve repair/replacement I wouldn't expect them to set the lash too. Anytime you replace a valve even with a stock one you will have to adjust lash most of the time due to the difference in length between the valves.

08-19-2008, 09:30 PM	#20
robbieshonda Scooby Guru Member#: 122306 Join Date: Aug 2006 Chapter/Region: South East Location: SubaruTuning.net Vehicle: 2002 Sti PTE 6262sp Interlagos Blue 551/441	When I do heads For Subarus or Others, If they have valve damage I cut the seat to be safe, you might not be able to se an oblonged seat ect. My workflow consists of disassembley, hot tanking/cleaning, checking all of the valves and the rest of the head magnaflux ect ( if needed) re surface the head, cut the valve seats, cut the valves if needed, adjust valve lash( machine the buckets and or the valve, Depending on the machine shop you take it too they should have all of the tools to to the job right but you should ask the machinest if he has worked on subarus( in this case) beforehand. Glad you got your heads back together. a Competition valve job ussually has a 3 or more angles. Some heads flow better with certain angles, and bowl blending or backcutting ect.