head gasket repair?
Thread Starter
Registered User
Joined: Jul 2009
Posts: 490
Likes: 3
From: San Diego
head gasket repair?
so i have the head off and im just wondering about getting it o-ringed. who should i go to for this and what does it require? do you need a special head gasket? should anything be done with the valves/seats while its at a shop? im knee deep and not really sure which route to take now. thanks
Registered User
Joined: Mar 2008
Posts: 4,389
Likes: 114
From: Orange County, California
special head gaskets aren't needed for o-rings. make sure you get it machined flat and that you keep the valve recession within specs. it's best that you have the valves cut down as much as the head gets cut. for example, my head was cut .006" so the valves were cut the same .006" to keep recession within specs. have the head magnaflux'd to check for any cracks.
1st Generation Admin
Joined: Jan 2005
Posts: 4,601
Likes: 118
From: Buies Creek, NC
Give careful consideration to recessing the valves as our heads run "Integral Valve Seats" meaning the original/OEM valve seats are cast as part of the head. The valve seats are then induction hardened. As such, if we grind too much from the original, integral valve seats, we can cut through the induction hardening. With that, integral seat must be cut out and replaced with a service seat. The you can grind all you want. Read the FSM instruction below . . . .
So if the head is smiling or frowning, you may need to have it milled. Has it been milled before? If it has, and if the mechanic marked the head like he should have, then you'll find the marks at the rear bottom right of the head. The book says ~
And finally, if you've dinged a valve and think you need a valve job, the book says ~
- You need to check the head between the cylinders for any grooves or etching where there might be some cylinder-to-cylinder leaking.
- You'll need to check that the head isn't warped too bad. The book says ~
- You'll need to check that the head isn't warped too bad. The book says ~
Originally Posted by The Book
Check for head distortion. The distortion of the combustion deck face is not to exceed 0.010 mm (0.0004 inch) in any 50.8 mm (2.00 inch) diameter. Overall variation end to end or side to side 0.30 mm (0.012 inch).
So if the head is smiling or frowning, you may need to have it milled. Has it been milled before? If it has, and if the mechanic marked the head like he should have, then you'll find the marks at the rear bottom right of the head. The book says ~
Originally Posted by The Book
The cylinder head combustion deck may be refaced in whatever increments necessary to clean up the surface and maintain the surface finish and flatness tolerances. The combined total of stock removed must not exceed 1.00 mm (0.03937 inch). The amount of stock removed each time must be steel stamped above the combustion deck edge, on the lower right-hand corner of the rear face. Check valve protrusion after head surface refacing.
Surface finish requirements are 1.5 - 3.2 micrometer (60-126 microinch).
Surface finish requirements are 1.5 - 3.2 micrometer (60-126 microinch).
And finally, if you've dinged a valve and think you need a valve job, the book says ~
Originally Posted by The Book
Cylinder head with integral valve seats can only be ground once. Previously ground integral seats must be replaced with service seats.
One X stamped into the head casting identify seats that have been ground previously.
Two XX's stamped on the head indicate service seats have been installed. Service seats can be ground.
On the integral seat head, if 0.254 mm (0.010 inch) or more has been removed from the head combustion surface, service seats must be installed.
To determine if the head has been previously resurfaced, before calculating valve depth, proceed as follows:
- Check the rear lower right corner of the head for stamping that would indicate previous resurfacing (eg .003).
- To verify the information, or if no amount is indicated, measure the head height.
- If the head height is 94.75 mm (3.730 inch) or greater, the valve seats may be ground, if they have not been ground previously.
One X stamped into the head casting identify seats that have been ground previously.
Two XX's stamped on the head indicate service seats have been installed. Service seats can be ground.
On the integral seat head, if 0.254 mm (0.010 inch) or more has been removed from the head combustion surface, service seats must be installed.
To determine if the head has been previously resurfaced, before calculating valve depth, proceed as follows:
- Check the rear lower right corner of the head for stamping that would indicate previous resurfacing (eg .003).
- To verify the information, or if no amount is indicated, measure the head height.
- If the head height is 94.75 mm (3.730 inch) or greater, the valve seats may be ground, if they have not been ground previously.
Registered User
Joined: Nov 2007
Posts: 1,816
Likes: 0
From: Maine
Give Butler & MacMaster's a call. They are in Southern Maine (Augusta area) so they can't be that far from you no matter where you are in NH. They are the big engine/ racing shop in Maine and know what they are talking about. One of the few in the state that even knew what o-ringing was when I was calling around. They gave a quote for $400 to mill the head flat, make the grooves, and set the rings IIRC.. might do a little more too.
Then again, there are some decent shops in MA I've been told as well.
Then again, there are some decent shops in MA I've been told as well.
Thread Starter
Registered User
Joined: Jul 2009
Posts: 490
Likes: 3
From: San Diego
Thanks guys. Also wondering if the residue I am seeing above the intake valves is normal. When I pulled the intake log I looked in and could see some dark semi moist residue above and around the valves. Is that because they arnt seating properly? It doesn't have any of the signs of being milled before. thanks again for the replies!
Thread
Thread Starter
Forum
Replies
Last Post
ted_pulliam
24 Valve Engine and Drivetrain
8
Jul 16, 2009 11:33 AM
wildchild97
Performance and Accessories 2nd gen only
7
Sep 25, 2007 02:44 PM