If a 1275 head had a crack in it.

[Legal Bill]

Sounds like using both methods is the way to go.

 

[Hap Waldrop]

Well with crack in the valve seat area, once the head is cleaned (I bead blast mine) you can see any cracks there, this is more common with MGBs heads, and you see it on the Cooper S with the big intake valves.

Once you've done magnfluxing yourself, you can understand it's pros and cons, for one as I mentioned , if you never done it, most wouldn't have a clue as to what they are looking at, it takes a trained eye in a magnflux test, there are several thing that could look like crack to the untrained eye, this is where the skill kicks in. It's great test for checking crankshaft journals, but not so much for heads or any item that would have area that you cannot see into. Plain and simple I don't magnaflux my cylinder heads, but I do pressure check them, and to add to this a manganflux test on a given cylinder head in the area that you can see would give less than desireable results unless the head was squeaky clean, degreased and beadblasted, otherwise carbon, paint, grime could hide a crack. Bill as you can see, I not wiggling on this issue, each to thier own, but I'll keep pressure checking my heads, for me just knowing and understanding the two differnet test and what they do, gives me all the direction I need.

I'll say this again, so hopefully it comes across, magnafluxing requires the human eye to see the crack, and you cannot see inside a port or a water jacket. As far as how long has PT been done, heck, it's been around forever, longer than magnafluxing, it not anything new.

 

[Legal Bill]

Thanks Hap. How long does it take to set up a head to pressure test it? I imagine you have to set it up on some sort of table that closes off the various openings???

 

[Hap Waldrop]

Basicly, they use a piece of plate that cover the bottomof the head, and mostly use a sheet of rubber to seal, thats all clamp to seal, then other areas of the heasd are sealed and area and one of the plugs has a fitting on it to inject the water at pressure, kinda work like a pressure checker that you would use on your radiator cap in a round about way.

 

[Deleted member 8987]

Basic plate isn't such a good idea.
Yeah, if water comes out, you gotta leak.
To have special plates, cut-out for combustion, and ports cut out if doing a head that has a water port alongside the intake/exhaust ports, so you can SEE where it is leaking, is either mandatory OR you end up with magg-ing the cylinder/ports/seats ANYWAY to find out what is leaking.

I NEVER recommended the hobbyist try magg-ing these at home.
It IS a skill, and I know what I am doing, yet have the machine shop do it for me, as they do it every day.

 

[regularman]

This is the first motor that I have had that used water and I could not find a "smoking gun" when I got it apart. I usually find a head gasket with a line in it or a major crack or a crack in the cylinder wall. This thing was really putting the bubbles out at the end before I took it down. It looked like alka selzer down in the radiator and this was with the motor just fired up from cold. The only thing I could find was that there was a dark area on the metal part of the gasket between 2 and 3. Also on the head in that area it something that looks like an inset on the head like copper or brass has been pressed into it. Same on both heads but the original head had about .002 recess where this thing is. That might be enough and what is causing my problem but I used the copper stuff and have yet to go on a good test drive with it. Had to work on my moms car this weekend electrical problems, but its fixed now. I got to run down to Mississippi for a couple days, then I can test it out. Hope to visit Tony on the way back home