Magnafluxing

YJJPWrangler87

YJJPWrangler87

New Member
Joined
Mar 12, 2006
Location
Raleigh
Anyone know where to get a cylinder head magnafluxed around raleigh/durham area. Im swapping the head gasket and want to make sure the head isn't warped or anything.

Zack
 
Any auto machine shop can do it for you. They will need to disassemble the head though to do it right, taking the valves out and so on. The alternative is to have it pressure tested instead. We do both at our shop, but unfortunately we are a good bit away.
Hope this helps
 
ok...well i dissabled the rockers and everything, but hte springs are still in there..whats a usual price for magnafluxing and pressure test? pros and cons to both?

Zack
 
magnafluxing is pretty simple. A electromagnet is used and when powered it creates a type of suction in the metal. When the fine metal powder is dusted between the magnet, it sucks into any cracks, making them very visible. Pressure testing is kinda the opposite. All water holes are blocked except one. Air is pumped in. We use 40lbs, more than any system should hold. It's just like finding a leak on a tire. Once the head is sealed, you spray soapy water everywhere and if there is a crack, bubbles appear. Although it really still needs to be fluxed on the deck surface since it is covered except for the combustion chamber, when it is sealed up.
As far as I am concerned fluxing works just fine for a cast head. But Aluminum heads can only be pressure tested to test for cracks. You didn't say what kinda of head you have.
as far as checking for warpage, a machined straight edge and feeler guages will tell you if it needs to be surfaced or not.
 
well its a stock head off a 92 6 cyl. HO XJ...the reason im changing teh head is b/c there was white smoke in exhaust..when i pulled the head off, the gasket was crispy...so if use a straight edge to check it? would that be good enuff...i just got quoted 150 bucks for magnafluxing...i really don't want to spend that much..any ideas?

What part of morganton are you in? My gfs dad works up there

Zack
 
Our shop is in Drexel off of exit 107. Give me a shout today if you wanna. 828 433 1586
If you can send it up with him I would be happy to check it out for you.
$150 is rediculous in my opinion. I could do a 3 angle valve job and surface it, and... magnaflux it for that amount
 
Chip-
you are cetainly the expert here, not me. But re-reading his initial question, magnafluxing would find cracks, but would not tell anything about warpage right?
To see if its true the straight edge and block off pressure check woudl be needed right?
 
to check the deck(warpage) we use a straight edge. We move it side to side, top to bottom, criss-cross, basically every which way possible. Using a feeler Gage (.002) to find any variations. If we find that the Gage will go under the straight edge, we double it to see if .004 will go. Different head and gasket combinations have different tolerances. Also looking at the water holes for electrolysis wear. If the head is straight, and the water jackets are in bad shape, then it still may need surfaced to insure a good head, gasket, block fit.
As far as the block off plate, we only use that when we pressure test a head. I covers everything except for the combustion chamber.
so to answer your question, yes magnafluxing will show cracks, but only the straight edge and feeler gages are needed to find if is warped. I prefer to surface a head just to get a good mating surface when re-installing it.
you may be referring to the plate that is used when honing a block. I is attached to the block when honing representing the head. This is usually only done on performance engines.
Any more questions I will be happy to answer.
Sorry to take so long to reply, but.... I was working doing heads all day!


On a side note.
There are several different ways to surface a head. I prefer the fly cut. Reason is I can zero the head and cut it as true as possible. I can straighten out a head that has been surface wrong ie at an angle either way. I can take the very minimum off or in a performance situation, take as much as the customer wants. Right down to the actual CC desired.
 
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