Heads back on...doesn't seal.

[Dire McCain]

As I have -posted, my cylinder head is a bit on the thin side having been surfaced at least three times.
I checked the valve to piston clearance and there was plenty of room, so I bought a new Toy gasket and put everything back together.

Runs great. Idles nicely. Plenty of power...

However, it's not sealing. White smoke, white crap in the oil cap...

Now, the head had been surfaced. The machine shop said it was flat...I torqued the bolts to 75. Followed the bolt pattern precisely. So I just don't understand what is happening here.

Apparently the head is screwed up somewhere, somehow. The block isn't cracked. So WTF?
I can't believe it isn't selaing. But I have the water everywhere- every damned cylinder- to prove it...

Any theories? Thin block causing compression and combustion to go beyond the ability of the gasket to seal it? Something inside the block screwed up? Termites? What?

Puzzled.

 

[kelson]

why was the head resurface? could the block be warped?

 

[Dire McCain]

Machine shop said it wasn't warped. They had to machine it to clean up the repair too a pit in the #6 cyl fire ring.

 

[suprarx7nut]

How long since you've been done? How many miles has it seen since you swapped HG's?

Did you change the oil multiple times?

 

[kamikazemkiii]

Have you pressure tested it?

 

[IJ.]

 

[kamikazemkiii]

[thumb]http://ij.supramania.com/wrong.jpg[/thumb]

lol, I wonder whats wrong?

 

[87GWSupra]

I would check to see if water jackets aren't corroded out. I had a head that did that, they where about 1mm away from the cumbustion chamber. If not that my guess is your block needs cleaned up or your torqe wrench is off.

---------- Post added at 07:55 AM ---------- Previous post was at 07:50 AM ----------

Oh almost forgot, make sure the head and block are clean! Wipe it down with alcohol or something to clean any oil or crap on the surface.

 

[hvyman]

could be the plug on the back of the head or the intake gasket leaking causing coolant to get in the cylinders. do a compression test and pressure test.

 

[GrimJack]

Leakdown test should help you narrow it down.

Not that it really matters at this point, if it's not holding pressure like it should, it has to come out and get torn apart again.

 

[Heavy D]

did you put all your vacuums in the right spot? probably have one mixed with the coolant and its sucking it up, would check that and like what every one said do compression test and pressure test on the cylinders and coolant

 

[IJ.]

did you put all your vacuums in the right spot? probably have one mixed with the coolant and its sucking it up, would check that and like what every one said do compression test and pressure test on the cylinders and coolant

Ummm care to explain this further...

 

[87GWSupra]

did you put all your vacuums in the right spot? probably have one mixed with the coolant and its sucking it up, would check that and like what every one said do compression test and pressure test on the cylinders and coolant

Haha nice, iv never seen this happen but with coolant lines going to TB I suppose it could. I will try next time I want to steam clean my pistons.
If you leak down have your radiator cap off so you can watch for bubbles. If it bubbles HG is not sealed. If it doesn't other issue.

 

[two-step-n]

what could the wite crap on the top of the in side of the oil cap be or mean?

 

[Keros]

When they machined the block, did they remember to bolt on that timing cover thing-a-mabob that needs to be machined with the block? Can't remember what it's called...

 

[Nick M]

As I have -posted, my cylinder head is a bit on the thin side having been surfaced at least three times.

And how much material was removed?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=42

.0039 or more warpage, it is best to get rid of the head. I don't care how flat it is after, and if you are using a MHG. Then again, it could be you and assembly, I don't know. I can't see from here.

Now, the head had been surfaced. The machine shop said it was flat...I torqued the bolts to 75. Followed the bolt pattern precisely. So I just don't understand what is happening here.

Both surfaces have to be flat, enough deck material, and torque sequence. One of them is not.

 

[Sawbladz]

The front timing cover would be my guess. If you didn't take it to them and specify that it needed to be done it is likely that they didn't do this necessary step.