1G No oil pressure to head??

[buhay6]

I finally got around to rebuilding a 6 bolt this last month to replace my tired 7 bolt.

When priming the engine I noticed I wasn't getting any oil pressure to the head, it was getting some oil but no oil pressure. I went ahead and finished up assembly then did first start Monday afternoon and noticed almost immediately that the cam lobs and lifters weren't seeing oil after running for basically a minute so I shut it down.

Then installed a mechanical gauge at the oil port by the turbo oil feed banjo. Started the engine back up and the oil galley that feeds the turbo is only receiving a trickle of oil when the engines rev'd above 2k rpm. My rotating assembly's seeing the correct oil pressure (12.5-13 psi at 900rpm) as far as I can tell, which tells me its a cylinder head only problem.

The heads most definitely a 6 bolt head not a 7 bolt head converted to 6 bolt, which rules out the possibility of the head stud being the culprit for low oil pressure.
The only other thing I could think of possibly being the problem is the HLA dumping the oil pressure instead of regulating it like it's supposed to, but is that even possible? Would it be dumping the pressure so fast that it would cease the oil flow to the rest of the cylinder head components?

I did do a little grinding to the oil supply port on the head like many suggest doing, but I did very little. Only ground the area down closest to the stud about 1mm and rounded the curve just a little, so I don't think it would be causing my problem either.


Any suggestions? I really can't think of anything else that could be wrong.

 

[pauleyman]

head gasket on incorrectly?

 

[buhay6]

very unlikely, there's only one way to put it on that looks right. I Really don't wanna pull the head back off but if worst come to worst then what choice do I really have.

 

[buhay6]

Ok so I've narrowed it down to the main oil feed to the head being the problem, I've tried the trick of grinding down the head stud .20 of a mm and still not getting any oil pressure to the head. So I'm pulling the head back off and going back over it.

 

[asexton6969]

Buhay6, you wouldn't be the first person or the last to do it.

 

[buhay6]

Head gasket was on correctly, I pulled the head last night.
I did find tho that the tear drop was only .066 of an inch deep which from what jafro's videos say is to tight, but would that stop oil flow?? not really understanding this.

 

[miliman13]

try this.....
It worked for me.

Connect a drill to your oil pump and spin it and see if oil shoots up from the block up the path it would take to flow towards the head.
This should do one thing, help you pinpoint the location of your failure.

If it shoots up, likely it's in the head... if it doesn't it may be in the block/ oil pump front case / galley.

 

[buhay6]

Already did that, I always prime my 4g's using that method. I got oil up to the head with in seconds of removing the head stud that goes through the oil gallery, it didn't squirt out but flowed up very quickly. So I'm certain my problem is in that area. Following Jafro's video I pulled the oil galley plug under the t-stat housing and checked for pressure there, got not even a drop. I pulled the head back off and now I'm going to port the tear drop passage out and verify the main oil feed into the head is clear of debris. ......I have to wait on a new H-gasket anyways because felpros fall apart after only being torqued down.