Checkin Mag heads for cracks

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JGC403

JGC403

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Is there a cheap way to check a set of magnum heads for cracks? The only way I know is to have them magnafluxed, and before the machine shop does that they will want to cook them. That adds up to more than a couple bucks. Is there a cheaper way? Would hate to spend money on heads just to find out they are cracked.
 
You can just look at the ridge between the valves to see. No need to magnaflux. Just hit the area real well with some brake clean and dry with compressed air. If there is a crack you'll see it.
 
UOP said:
You can just look at the ridge between the valves to see. No need to magnaflux. Just hit the area real well with some brake clean and dry with compressed air. If there is a crack you'll see it.
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I thought the cracks that the magnum heads are prone to aren't visible with the naked eye.
 
Not what you want to hear but. If buying core or reusing used. Have them cleaned and checked. Cost me $30 to have this done.
 
Take a wire brush on a drill and clean them right between each valve.
Clean them off with brake clean right between the valves.
Let everything dry.
Visually inspect them.
Hit them again using a straw on the brake clean right between the valves, just a little brake clean not a lot.
If they are cracked usually the crack will be the last place the brake clean evaporates from.
This is about the cheapest way I know without paying the shop to inspect them
 
Take it from a guy that mags heads. Some cracks simply can't be seen. If they pass the visual and brake clean check, then have them magnufluxed. I went through my core heads a while back. After tossing out the ones that didn't pass the visual check, which was about half of them. I mag checked the rest to find about half of those were cracked as well.
 
I have the magnaflux powder testing deal with the electromagnet. But the cracks in Magnums I've found could be seen after wire brushing the area between the valves. Also - not all cracks are fatal. Many do not go to water, or migrate there, and are never an issue.
 
Both heads on my motor have cracks, easily visible too. They don't leak and I'm not worried about it.
 
skrews said:
take it from a guy that mags heads. Some cracks simply can't be seen. If they pass the visual and brake clean check, then have them magnufluxed. I went through my core heads a while back. After tossing out the ones that didn't pass the visual check, which was about half of them. I mag checked the rest to find about half of those were cracked as well.
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JGC403 said:
Is there a cheap way to check a set of magnum heads for cracks? The only way I know is to have them magnafluxed, and before the machine shop does that they will want to cook them. That adds up to more than a couple bucks. Is there a cheaper way? Would hate to spend money on heads just to find out they are cracked.
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Once you have the bowl/valve seat area clean the easy check is to spray liberally with Brake parts cleaner,then blow and watch the area your checking. The BPC will dry way fast on the surface but you'll see cracks as the fluid slowly evaporates from the cracks . Yep,Learned that trick years ago for cheap fluxing of TAFC cranks between rounds. this will not find a very minor crack but if the cracks go to water the chamber will be very clean and nothing like the chambers next door. Most magnum heads are cracked.
 
JGC403 said:
OK. I thought if they were cracked, they were junk.
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Naw, the way I see it, if one starts to show signs of leakage a remanned replacement is a cheap ($160) fix. I don't plan on putting any money into them with fancy valve jobs or port work, but I ever get to that point I'd be looking at EQ castings anyway.
 
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