95.5-2004 Tacomas & 96-2002 4Runners 4th gen pickups and 3rd gen 4Runners

Mirror Finish Anyone? (Head Surface Problem)

Thread Tools
 
Search this Thread
 
Old Mar 1, 2011 | 06:33 PM
  #1  
trx125's Avatar
Thread Starter
Registered User
 
Joined: Jan 2005
Posts: 399
Likes: 0
From: Youfalla, Al
Mirror Finish Anyone? (Head Surface Problem)

I just got my heads back from the machine shop. My father in law picked them up for me. The nearest machine shop that specialized in toyota heads is over an hour drive each way. I told them exactly what kind of gaskets I was using and this is what I received back from them. Not only can you see the scratches, you can feel them as well. This is suppose to be a very reputable shop that handles toyota heads for dealerships all around our area. I am going to call them tomorrow to see what needs to be done. My plan was to use Hylomar sealer and a MLS gasket. Oh well, I will get off my soap box now. I am just curious as to everyone's thoughts on this.


Last edited by trx125; Mar 2, 2011 at 07:12 AM.
Reply
Old Mar 1, 2011 | 06:51 PM
  #2  
trx125's Avatar
Thread Starter
Registered User
 
Joined: Jan 2005
Posts: 399
Likes: 0
From: Youfalla, Al
My thoughts exactly. It looks like they dragged behind a car on the road to mill them flat!
Reply
Old Mar 1, 2011 | 07:05 PM
  #3  
danimal92sport's Avatar
Registered User
 
Joined: Aug 2008
Posts: 102
Likes: 0
You may be used to seeing a milled finish - this appears to be belt sanded (not joking). This is a known technique that many shops use to level the surface, but isn't exactly...exact. Most shops use 40 - 100 grit silicon carbide belts to do this, which would lead to a finish like what is shown.

I'm not stating that this is either a good or bad method, as I'm no head surfacing expert. Just guessing at the technique.

-Dan
Reply
Old Mar 1, 2011 | 08:10 PM
  #4  
KU_MechE's Avatar
Registered User
 
Joined: Sep 2006
Posts: 67
Likes: 0
From: Kansas City, KS
I believe the best machining available for a cylinder head is surface grinding. It looks like that was used here.
Reply
Old Mar 2, 2011 | 06:57 AM
  #5  
sportscarfan's Avatar
Registered User
 
Joined: Nov 2010
Posts: 18
Likes: 0
From: CO
The right thing to do is to call the shop and have a friendly conversation about what they did.
You do not want a mirror finish - the gaskets won't seal, much like piston rings need a crosshatch'd hone finish to seal.
If you have a known precision flat (purpose ground bar, or surface), check it for straightness.
Reply
Old Mar 2, 2011 | 07:11 AM
  #6  
trx125's Avatar
Thread Starter
Registered User
 
Joined: Jan 2005
Posts: 399
Likes: 0
From: Youfalla, Al
I called the shop and they said they do a belt sanding on all their heads. I have never used an MLS gasket, but I was under the understanding the head surface had to be below a certain RA. I was plan on using the Hylomar in conjunction with the gasket as is. After talking with the shop in the begining, I made sure they knew I what I was using and the kind of surface it needed. The rest of the work on the head is excellent and the finish would be fine for composite gaskets. The surface is trued and flat now, just really rough.
Reply
Old Mar 2, 2011 | 07:11 AM
  #7  
Potomacduck's Avatar
Registered User
 
Joined: Jul 2006
Posts: 287
Likes: 0
From: New Market, MD
That doesn't look like a problem to me.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
RedRunner_87
95.5-2004 Tacomas & 96-2002 4Runners (Build-Up Section)
84
Jun 1, 2021 01:51 PM
lledwod
Items Wanted
1
Aug 30, 2016 01:03 PM
KBar
86-95 Trucks & 4Runners
3
Jul 13, 2015 06:01 PM
dropzone
Hot Deals - Free Stuff - Craigslist
0
Jul 11, 2015 10:17 PM




All times are GMT -8. The time now is 02:48 AM.