RB25 conversion Stage 9 - Installing the head gasket, oil pump, sump and remove the standard oil modene

I finally got around to doing some more work on the engine this weekend after a few weeks of inactivity. It's taken a while getting hold of an oil pump gasket, but I finally got it delivered so decided to get on with the build.

First off I fitted my new head gasket and installed the head on to the block. Before placing the head on the block it's worth making sure number 1 piston is at the top of the bore as per the Nissan guidelines. This will make cam timing much easier later on down the line! I followed the Nissan guidelines for torquing all the head bolts in the correct order. You can find directions for doing this in the R33 Engine Manual or R32 GTR Workshop Manual in the manuals section of this website (click here) Also make sure you install the head bolt washers the correct way up for all bolts (bevelled edge up). Here's the head gasket on the block and a pic of one of the head bolt washers - you can see the bevelled edge...

With the head on I rotated the engine on the stand and got to work on the bottom of the lump. First off I bolted on the oil pickup...



Then I removed the old crank seal from the flywheel end crank seal holder. This took a fair bit of hammering with a drift to remove as the seal is pressed in tight. To fit the new seal into the case I gave the seal and case a smear of Graphogen for lubrication and used a block of wood and a wooden mallet and just hammered it in. Once the seal was in place I got some Loctite 5926 Flange Sealant and applied it to the back of the seal case. Then, I gave the crank and the seal a smear of Graphogen and bolted the seal in place.





On to the other end of the block. Fitting the oil pump was simply a case of placing the paper gasket on the block, putting some Graphogen on the crank and the oil pump and bolting the oil pump in place. Luckily the brand new N1 oil pump I bought had a new oil seal pre-installed so I didn't have to worry about pressing one on.





Give the sump a good coating of the Loctite, then bolt up to the block. Again refer to the Nissan manuals for the tightening sequence for the bolts. Once fitted remove all the excess sealant (because it just looks ugly otherwise!). I bought a Driftworks magnetic sump plug and installed this to finish off the bottom of the lump for now.






My last job this weekend was to eliminate the oil modene (the standard oil/water cooler) that the oil filter screws on to. I need a sandwich plate for my Mocal 19 row oil cooler and a second sandwich plate for oil pressure and temperature gauge senders. If I had simply fitted these sandwich plates on to the oil modene the oil filter would have stuck out a long way away from the block and there probably wouldn't be room in the engine bay.

The way around this is to get an oil filter thread from an L28 (the engine found in the Datsun 280Z). I bought mine from the United States from a company called Raw Brokerage. They were great value and very fast delivery to the UK, highly recommended!

Unscrew the standard interface to the oil modene from the block (I used a monkey wrench). Screw in the L28 oil filter thread and then add any sandwich plates and the oil filter. Much neater! My gauge sandwich plate has an outlet that the standard oil pressure gauge sender screws in to, so the standard oil pressure reading on the dashboard will still work. The water lines that previously went into and out of the oil modene simply need to be plumbed to bypass the oil modene.







And finally I couldn't resist a quick test fit of the painted rocker and cam belt covers just to see what it'll look like when it's all together. Should look excellent! I have some Tomei cam shafts arriving in a couple of days, so next week there'll be a write-up of the install :o)