Intake Seat Repair - Cast Iron 197 head
 

I have water leaking past an intake valve seat that was replaced a number of years back. When the valve seat was replaced it was put in too deep and got into the water jacket. At he time JB Weld has put in with the new seat which worked for a number of years. Tried to repair with Seal-All Head and Block sealer but does not last for any length of time before it starts leaking again.

Are there any shops that could successfully weld the back of the seat area up and re-machine a pocket for new valve seat?

I have used this stuff for many years. It does a good job and the repair is permanent. https://goodson.com/collections/crac...cts/fluid-weld

A very timely post for me, as I have a 197 head that needs an intake seat repair due to a deep rust pit.

What is a safe depth (and diameter) to avoid water or cracking problems?

I know 0.200 is too much

The problem is that most seats that will work for a 2.11” valve are .250” tall and the thickness of the chamber floor in a lot of areas is on average .180”.
I would suggest that when using one of these seats that it only gets installed to a depth of 3/16” or .187”, and then also have a tube of that fluid weld on hand.

This depth of install will also allow the usage of the stock 30 degree seat angle if needed.

Here is a cut away a member posted of the exh side of a 6X head of 98 CCs so it will be real close to the depth of the chamber in a 197 head.

As you can see at least on the right side bottom of this photo there is not much meat there and this casting does not look to much wall thickness loss due to corrosion either.

Do you think fluid weld will fix this once new seat is pressed in?

https://photos.app.goo.gl/L4Lf8KBAfWzeVBiG9

https://shop.silver-seal.com/storefr...-number=30333#

Good read. Thank too Mgarblik for posting product. Check the pdf files.

Will the silver seal fluid weld work on a cylinder head chamber that has been "pinned" & was not pressure tested (result slight weep of coolant, then removed)?

Or would it be better for the cyl head (another 197) need to be machined for installation of a propperly cut down seat ring?

IMO, always better to install a seat without breaking into water than repairing one that has broken through. But some rare heads, no choice, you have to try and save the casting. Recently put 8 sleeves in a 65 Hemi Block. What a complete mess. That thing should have been thrown in the scrap pile. But the owner needed to save the casting for some rare restoration. It will never be as good as a non-sleeved block. Cost a fortune to fix and still a marginal foundation for a once great engine. If you have a virgin-un-cut head, I would use it and install shallow seats. JMO.

And the good thing about cast iron heads is that shallow seats will stay in place, on a aluminum head your sunk, unless you weld up the bowl.

And if some of the chamber also needs welding the cost of machining and or grinding that back to match the unharmed chambers and to re-port the valve bowl cost more then the welding work !

Sort of off the OPs topic, but on a Pontiac, you know, the cool engines, how many sleeves in a block is acceptable before it becomes a negative ?
I have a couple of 400 blocks that might need a sleeve or two.

Are any of the bores in these motors you have cracked through to the water jacket, or cracks extending down close to the main web area?

Indy cylinder heads Repair weld and remachine for a new seat?

My experience hasn't been great putting a single sleeve in a Pontiac, other than the 4 corners. When doing cylinders, 3,5,4,6, I have had to do them in pairs. They all need to have a shelf machined near the bottom of the bore for it to sit on. I leave the sleeves .010+ tall and put a torque plate on without gasket to really seat the sleeve. Usually leave it on a couple days, then machine the deck and hone it with plate and gasket. Sleeved blocks never seem to stay as straight and round as all iron blocks.

I wonder if that is due to the sleeve not being seasoned from usage like the rest of the blocks cast iron, or if the removal of the seasoned cast iron to make room for the sleeve now stresses the block in a different way.

Have you ever seen the main bore go out of alignment after putting in more then one sleeve?

I think you may have something there. In race blocks that are run and serviced a few times a year or once a year, after a few freshen-up hone jobs they do seem to settle in and stay straighter. Not sure about the main bores, because we line hone them anyway after the sleeves are installed. Something to check. We line hone everything that's getting a complete overhaul.

Think of it this way. The original (continuous) cast iron can push and pull in reaction to the flexing that comes from operation. Since a sleeve is disconnected but pressed in, it can push but not pull. So you have reduced ability to hold the block's shape.

Eric