MTFCA Forum

I have found cracks between the intake and exhaust valves in two places on my engine. The valve seats are not cracked, just the block. Engine seemed to run fine before teardown to replace the Babbitt in number one rod. Is this something to be concerned about?

Mike, if there are no cracks in the valve seats, you likely have hardened valve seats fitted. They may indeed have been fitted to repair cracks in the valve seats discovered on a prior inspection. If this is the case, the repair is entirely satisfactory, as there is no water jacket under the seats.

Allan from down under.

Post a picture.

Hopefully I can get these pictures posted. Cracks do not extend in the valve seat.

Allan wrote: ↑

Fri Feb 07, 2020 10:52 pm

... there is no water jacket under the seats.

Allan from down under.

Yes, there is.

Good picture!

Please clarify which valves these are. That seems to look like it’s between a pair of intake valves.

I have the impression that maybe the press fit of the valve seats was too tight and maybe caused that when the inserts were installed.

Might not be an issue, but if the crack is between two intake valves, it maybe should be stitched.

They need fixing, if not it's not if but when the head gasket will blow.

The crack is between intake valves on cylinders 1 & 2, and then again between intake valves 3 & 4.

I looked back at my first post. I made a mistake in thinking it was between intake and exhaust. As stated above, the cracks are between intake valves.

Those need to be repaired .
We don't see this crack to often but when we do it has to be repaired.
We use metal stitching and it is a seamless stress free repair.
With hardened valve seats installed it will never crack again in that area.

I live in Southern Iowa. Does anyone know of a shop that does this kind of repair?

Any decent automotive engine rebuilding shop should be able to do it. Make sure they have experience. There are also industrial businesses that specialize just in crack repairs. These are probably the best places to go. Generally there might only be one such business in a large city with lots of manufacturing businesses. See if there is anything around Des Moines. The going rate in Milwaukee was $80 per inch last time I checked a couple years ago.

FWIW I have the same cracks in my '12 block. They have been there about 3 or 4 years ago and so far have not changed or affected performance. I have the hard seats like Mike. It'd be on the list of things to fix during the next major O/H