Double Check Me Before I Boat Anchor My Engine Block (1 Viewer)

[lelandEOD]

Guys, I'm ready to have my engine shop drill and tap my 1HZ engine block to accept factory 1HDT connections. I've been in contact with Damoperu and his feedback has been really valuable as to how best to approach this critical step.

My engine shop is going to outsource this to an industrial machinist who [I think] has a horizontal mill which should make the task easier. He should be able to fix the block to the mill table from the bell housing side to ensure everything stays square.

It's a freaky operation since we are literally drilling almost 6 inches into the block casting/webbing between cylinders 4 and 5. Yeesh.

I stopped by the shop today and got a chance to really look the block over and [now] think I have a pretty good understanding of what we are trying to accomplish. Here is the front of the block. The lower of the two oil galleys (circled in red) appears to be the primary oil galley that feeds oil to the mains, piston skirt oilers, etc.

Here's the left side of the block where that primary oil galley travels the horizontal length of the block:

Here's a photo of Damien's block where he had it drilled and tapped for the turbo oil supply line:

This is a photo of my block with the arrow on the un-drilled casting boss where the drill bit must plunge:

Here is a shot inside the block between #4 and #5 where the hole must be bored. I've been unable to find a spec for the factory diameter of the new galley we need to drill. Damien's advice was to drill it to the same diameter as the ID of the turbo oil supply pipe. That's almost 1/4" so that freaks me out a bit as the webbing between the cylinders is not very thick at all. Double-yeesh.

Thoughts, suggestions, sarcastic remarks? All input would be appreciated!!!

 

[doug720]

Bold!

Are the 2 blocks exactly the same where the hole will be made?

Is there another way to supply oil to the turbo?

Is this a common mod?

I don't own or know these diesel engines, and have never seen one in person. But diesels in general have tremendous stress on many components.

If the answers are yes, and the machinist is good, go for it. If any of the above are no...???

 

[mudgudgeon]

Sarcastic remarks?

Your nucking futs!


Is your machinist confident? Or got doubts?

I don't reckon you need a 1/4" gallery to feed the turbo, but even if you cut the drill size down to 3/16 you're splitting hairs.

I contemplated this for about 3 minutes when I was turboing my 1hz, but too complicated and not enough gain.

I don't like the typical braided line that goes up and over to the turbo, so I ran my oil feed from a tee at the oil pressure sensor port and ran a braided line down, around the front the oil pan, then back up to the turbo.
I used oil pan bolts to clip the line in place.
This could be done really neatly with a hard steel line.

 

[davegonz]

I did the braided hose route, too.

I think there was a Safari turbo write up out there that documented where to drill?

 

[Dougal]

I tried the same thing on a completely different brand and model of engine. I managed to strike oil, but not enough pressure or flow to feed a turbo. Must have just nicked the gallery instead of hitting it square. Because it's extremely hard to maintain that alignment working blind.

Ended up blanking it off and using a different feed. I would not try to drill a block again like that. Too much work for a low chance of success and almost no gain even if you are successful.

 

[lelandEOD]

I appreciate the comments, fellas. I just got word from my machinist that the oil drilling explorative surgery was successful.
(Whew. I can breathe again.)


The plunge depth was indeed almost 6" and the machinist commented that this operation really must be done on a horizontal mill. He struck the primary oil galley and the #5 main bearing galley at the same time. I had him face the boss to ensure a good seal with the banjo fitting as well. He also drilled and tapped for the turbo support bracket and installed the pressed-in oil return tube fitting on the main bearing cap. After a five month wait, I should finally be able to start assembling the short block.

 

[Squash]

Well done!
It's great to push the comfort zone.

 

[lelandEOD]

Just want to close the loop on this issue in case anyone searches the archives.

Everything is home and I'm very happy with the results. Here is a shot of the drilled and tapped turbo stay and the correct oil return fitting from a 1HDT:

And here is a shot of the oil supply hole. The machinist mentioned that it's not perfectly centered on the cast boss because he bored the hole based on measurements taken from a reference point on the bearing cap to the center of the mail oil galley. He perfectly intersected the oil passage dead center.