1FZ-FE Head Pressure tested (1 Viewer)

[redshiftquasars]

I've got my heads at a local machine shop and was told that the head was pressure tested at 60PSI overnight and that some small bubbling occurred overnight. The machine shop has informed me that regular operating PSI is between 18 and 20 PSI but they're testing at 60PSI may indicate that the head is cracked.

couple of questions:
1. are the PSI numbers shown above correct?
2. should i be concerned with the 60PSI test showing the bubbles
3. should i just get a reman head?

 

[Woofythewolf]

Unfortunately, you can't magnaflux aluminum, but you can dye test it.
Smooth/polish the area around the crack if possible, and do that. I think they have kits at auto parts stores?

The unfortunate thing about cracks is that they will continue to propagate even if the force making them to do is very small, far smaller than the force required to initiate the crack. The only way to stop a crack is to remove the cracked material and put in new, or to clamp it down so it never sees any tension at the crack (which is generally not possible).

 

[flintknapper]

I've got my heads at a local machine shop and was told that the head was pressure tested at 60PSI overnight and that some small bubbling occurred overnight. The machine shop has informed me that regular operating PSI is between 18 and 20 PSI but they're testing at 60PSI may indicate that the head is cracked.

couple of questions:
1. are the PSI numbers shown above correct?
2. should i be concerned with the 60PSI test showing the bubbles
3. should i just get a reman head?

Why are they pressure testing at over twice normal testing pressures and why overnight?

Typically there is a 'pressure decay' time/window that is simply pass/fail.

"Also, observation of bubbles doesn't necessarily mean the leak requires replacement of the cylinder head. Air can sometimes flow through leaks that water and coolant *at operating temperature* will not, due to a larger molecular size. In fact, coolant at operating temperature has a viscosity that is approximately 53 times greater than air."

You might question them about their concern.

 

[zapatius]

I've got my heads at a local machine shop and was told that the head was pressure tested at 60PSI overnight and that some small bubbling occurred overnight. The machine shop has informed me that regular operating PSI is between 18 and 20 PSI but they're testing at 60PSI may indicate that the head is cracked.

couple of questions:
1. are the PSI numbers shown above correct?
2. should i be concerned with the 60PSI test showing the bubbles
3. should i just get a reman head?

They can TIG weld a crack. Mine had one small crack and the head shop welded it.

 

[Woofythewolf]

They can TIG weld a crack. Mine had one small crack and the head shop welded it.

How many miles did yours have?

My head was pretty warped, but basically no shop wanted to do anything to it because they thought it was too old and heat cycled/aged, so if they did anything it would just crack. In my case none of the SF bay area heat treaters would straighten it, which is even less stress than welding on it.
Mine had roughly 350k miles at an estimate, the odo was maybe 290k but broken for over a quarter of its life.

 

[zapatius]

Mine was about 160k miles. I cracked my original one in multiple places. This was from a part-out rig. It was completely straight; however, they suspected it had a stress crack due to improper removal (not sequenced).

 

[redshiftquasars]

engine and head had 300k.

ok the first link is for a diesel engine but appears to be referenced from many engine builders(gas ... diesel...). Second link has more information from the author regarding testing methods and PSI on how to find cracks, pinholes, leaks...
found this:

http://www.engineprofessional.com/TB/TB042517-2.pdf

Holes in Your Head … Or The Fine Art of Crack Detection

Let’s talk about why we check for cracks in heads and blocks. The obvious reason is that you can’t fix what you don’t know is there. Cracks and pinholes in heads and blocks can lead to a loss of power in the engine, resulting in poor performance. That, unfortunately, is the best-case scenario...

goodson.com

a leak at 60PSI may be extreme but will go down the path of finding a reman head. will keep you posted.

 

[flintknapper]

Unfortunately, you can't magnaflux aluminum, but you can dye test it.
Smooth/polish the area around the crack if possible, and do that. I think they have kits at auto parts stores?

Dye test is pretty easy. Messy....but not complicated. Just finished doing that to a 25hp Kawasaki engine for my Zero Turn. The products can be ordered from a number of sources. Good for heads and cylinder bores especially.