Does anyone know how to test cyl heads?

[sweetdiesel]

If someone wanted to check for crack on the cyl heads...How?

Press test? make a plate? and bolt them to it? then what?

what about cracks that only appear at normal ECT temps and low is good? the oven?

 

[mytmousemalibu]

Have them sonic checked? since magna-fluxing only works on ferrous metals. Unless its physically visible, i kinda doubt you'll see any if there is some. Unless someone makes somthing now that you can spray on it to define a crack line?

 

[McRat]

Classical method is to pour solvent into an assembled head's port and see if anything gets damp. But internal cracks might not show. "Zyglo" is a spray penetrant that can find cracks too.

If the crack doesn't go into the combustion chamber, the head is perhaps usable as a race only head, since bleeding a little pressure isn't going to kill you.

But combustion pressure leaking is a killer.

 

[sweetdiesel]

Have them sonic checked? since magna-fluxing only works on ferrous metals. Unless its physically visible, i kinda doubt you'll see any if there is some. Unless someone makes somthing now that you can spray on it to define a crack line?

thanks......I wish we could magnaflux them

Classical method is to pour solvent into an assembled head's port and see if anything gets damp. But internal cracks might not show. "Zyglo" is a spray penetrant that can find cracks too.

If the crack doesn't go into the combustion chamber, the head is perhaps usable as a race only head, since bleeding a little pressure isn't going to kill you.

But combustion pressure leaking is a killer.

I have combustion press leaking and need to find out where!


Thanks for all your advice Pat

 

[mytmousemalibu]

Good call on the Zyglo Pat! I forgot about that stuff! Might be want you want Simon:hug:

 

[WolfLMM]

Simon X-ray it!!

 

[Turbo Buick 6]

MagnaFlux brand makes a dypen kit thats about $50 and can be ordered at most welding stores. If you PT them then give me a call and I will walk you through a special procediure for finding small cracks:hug:

Simon X-ray it!!

Its worth a shot but it is usually pricey and with all the voids in the heads it would be easy for a crack to hide on the film. If you do RT them make sure they take lots of eliptical shots a many different angles so there is less chance of a crack hiding

 

[sweetdiesel]

magnaflux Zyglo procedure
http://www.magnaflux.com/files/library/operating/Zyglo~reg_Bulk_Operating_Instructions.pdf

 

[Trippin]

Make a plate that bolts to the head gasket surface of the cylinder head with cutouts for the cylinder bores. Hint: Use a head gasket as a template.
Bolt it up with some 1/4" rubber sheet as a gasket, don't forget the cutouts for the cylinder bores.

Make another plate that bolts to the open water jacket at the end of the head and drill and tap for 1/4" pipe fitting. Again using an old gasket as a template. Seal this one up with a regular Duramax gasket.

If checking an LB7 head be sure to have the injector cups installed along with the injector clamps and something in between the two to keep the cups from blowing out. We made some aluminum fittings for just this purpose.

Get an adjustable air pressure regulator and set it for 30psi. Plug the regulator into shop air and the regulated side into the end plate on the cylinder head. Now submerge the cylinder head in a tub of water and look for leaks in the ports. If none are present and your rubber head gasket is sealing properly gradually increase the pressure to 60 psi, roughly double what the cooling system sees.

Hope this helps,

Guy

 

[bullfrogjohnson]

Make a plate that bolts to the head gasket surface of the cylinder head with cutouts for the cylinder bores. Hint: Use a head gasket as a template.
Bolt it up with some 1/4" rubber sheet as a gasket, don't forget the cutouts for the cylinder bores.

Make another plate that bolts to the open water jacket at the end of the head and drill and tap for 1/4" pipe fitting. Again using an old gasket as a template. Seal this one up with a regular Duramax gasket.

If checking an LB7 head be sure to have the injector cups installed along with the injector clamps and something in between the two to keep the cups from blowing out. We made some aluminum fittings for just this purpose.

Get an adjustable air pressure regulator and set it for 30psi. Plug the regulator into shop air and the regulated side into the end plate on the cylinder head. Now submerge the cylinder head in a tub of water and look for leaks in the ports. If none are present and your rubber head gasket is sealing properly gradually increase the pressure to 60 psi, roughly double what the cooling system sees.

Hope this helps,

Guy

This is how we do them at Cat

Simon I will try to take a pic of our setup tomm.

 

[sweetdiesel]

Make a plate that bolts to the head gasket surface of the cylinder head with cutouts for the cylinder bores. Hint: Use a head gasket as a template.
Bolt it up with some 1/4" rubber sheet as a gasket, don't forget the cutouts for the cylinder bores.

Make another plate that bolts to the open water jacket at the end of the head and drill and tap for 1/4" pipe fitting. Again using an old gasket as a template. Seal this one up with a regular Duramax gasket.

If checking an LB7 head be sure to have the injector cups installed along with the injector clamps and something in between the two to keep the cups from blowing out. We made some aluminum fittings for just this purpose.

Get an adjustable air pressure regulator and set it for 30psi. Plug the regulator into shop air and the regulated side into the end plate on the cylinder head. Now submerge the cylinder head in a tub of water and look for leaks in the ports. If none are present and your rubber head gasket is sealing properly gradually increase the pressure to 60 psi, roughly double what the cooling system sees.

Hope this helps,

Guy

That does help Thankyou Guy
one thing though is what if the heads only leak when warm?
would heating the water in the tub be a idea?Or do I attempt to heat the head before checking?
I geuss if I try testing first then worry about the heating of the head

This is how we do them at Cat

Simon I will try to take a pic of our setup tomm.

Cool, thanks Travis

 

[LB7Diesel]

Put the Head in a turkey fryer then maybe boil the water, remove from heat, then pressurize??? Just a dumb idea from Flori-DUH:hug:

 

[sweetdiesel]

Put the Head in a turkey fryer then maybe boil the water, remove from heat, then pressurize??? Just a dumb idea from Flori-DUH:hug:

Hmm, I have a turkey fryer

 

[Trippin]

That does help Thankyou Guy
one thing though is what if the heads only leak when warm?
would heating the water in the tub be a idea?Or do I attempt to heat the head before checking?
I geuss if I try testing first then worry about the heating of the head

The reason we test at 60 psi is to find those little fizzers that only open up when the head is hot. It's amazing what you don't see at 30psi, yet becomes very apparent at 60 psi.

 

[LB7Diesel]

Hmm, I have a turkey fryer

You might just go-ahead and do 60psi like Guy said and keep it out of the boiling water. I can see that air fitting coming loose and spraying your ass with hot water! It would happen to me I guarantee it with my luck.

OR

Maybe one of your buddies will take one for the team and look into the pot for leaks.:hug:

 

[mplteddy]

I'm pretty sure Stu has a setup like that built to check heads Simon, I should call him and see if it's big enough for a d-max head though...

 

[LBZ]

Hmm, I have a turkey fryer

Note to self: DO NOT eat deep fried turkey that was cooked at Simon's.