- Thread starter
- #26
KeelesKustome
15+ Year Contributor
- 882
- 15
- Dec 29, 2007
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Waverly,
Tennessee
something i just found while still researching:
October 29th, 2009, 07:29 AM
As some of you may already know, I blew my FP3052 a few months ago. The reason was unknown, and I did a lot of research and had no luck finding a likely cause, though I was pretty sure it was from oil starvation. I accidentally stumbled onto a few threads on DSMTuners just a few minutes ago, and I think they explain why the GT30r CHRA most likely failed.
When installing a 2g head on a 6bolt block, you have to enlarge the holes on the head to accept the larger, 12mm 1g head studs. Something I was unaware of is; The main oil feed for the head is through one of the head stud holes. (see picture 3b)
I believe that I did not enlarge them enough, even though the head only needed a little attention to make it "fit". In the thread I linked above, it explains that the larger 1g/ARP studs interfere with the head oil passage creating higher oil pressure and sometimes oil starvation. Since the 3g lifter swap I have only had lifter tap once or twice. I assumed that there wasn't an insufficient oil condition at the head. That is, until my newly 'fed-from-the-head' turbo failed after only a few months of hard driving.
This head has had oil port mod 1 done.
The head boltholes have been reamed for the 1g head studs. To prevent any issues with oiling issues in the head,
I have reamed the bolt hole that is in the path of oil flow to .500 the bolt hole was .470 the ARP head stud being used is .465
Leaving only appox. .005 total or .0025 clearance on either side around the head stud. I feel the addition .030 will alleviates any problem with oil into the head.
is this still concerning the simple oil port mod, or is this something different all together.?
October 29th, 2009, 07:29 AM
As some of you may already know, I blew my FP3052 a few months ago. The reason was unknown, and I did a lot of research and had no luck finding a likely cause, though I was pretty sure it was from oil starvation. I accidentally stumbled onto a few threads on DSMTuners just a few minutes ago, and I think they explain why the GT30r CHRA most likely failed.
When installing a 2g head on a 6bolt block, you have to enlarge the holes on the head to accept the larger, 12mm 1g head studs. Something I was unaware of is; The main oil feed for the head is through one of the head stud holes. (see picture 3b)
I believe that I did not enlarge them enough, even though the head only needed a little attention to make it "fit". In the thread I linked above, it explains that the larger 1g/ARP studs interfere with the head oil passage creating higher oil pressure and sometimes oil starvation. Since the 3g lifter swap I have only had lifter tap once or twice. I assumed that there wasn't an insufficient oil condition at the head. That is, until my newly 'fed-from-the-head' turbo failed after only a few months of hard driving.
This head has had oil port mod 1 done.
The head boltholes have been reamed for the 1g head studs. To prevent any issues with oiling issues in the head,
I have reamed the bolt hole that is in the path of oil flow to .500 the bolt hole was .470 the ARP head stud being used is .465
Leaving only appox. .005 total or .0025 clearance on either side around the head stud. I feel the addition .030 will alleviates any problem with oil into the head.
is this still concerning the simple oil port mod, or is this something different all together.?