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How to make a rear sump pan for your rb using basic tools/tig


240zdan

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The purpose of this writeup is to help out fellow hybridz members with the RB oilpan dilemna. As you may already know, most rb series engines came with a front sump pan, or in the case of the gtr motor, a front sump pan with a diffrential built into it.

I was able to fabricate an oilpan, from scratch, using basic tools, with the exception of a milling machine and a tig.

Now a milling machine is probably not necessary, and I will explain why later. You can always get a machine shop to do some milling for you. Took me 1/2 hour, so shoudlnt cost much.

 

Materials needed:

3/8X1" aluminum flatbar

1/8" aluminum sheetmetal

Stock GTR pan

 

Tools needed:

Aluminum cutoff wheel and grinder

Two sizes of drill bits (cannot remeber exact size at the moment)

Vise

Emery cloth/sanding blocks

Angle grinder/sanding disc/etc..

Bandsaw

 

1. Start with the 3/8 by 1" flatbar. This will be your flange. Now you are probably thinking "wait a sec... how will this be my flange?". Easy. Using your cut off disc, cut reliefs into the flatbar to produce bends. Try to follow the original flange as well as possible. You will have to do several relief cuts for tight radius bends. When youre done it shoudl look somethign like this.

IMG_0862.jpg

 

 

2. Grind bevels into the relief cuts so the weld penetrates. Weld it up, but make sure its clamped to a table to prevent excessive warpage.

IMG_0875.jpg

 

3. Next I milled off the welds so it blends with the existing surface. Now, im not 100% sure, but you could get away with some sanding discs on an air tool, and then a finnaly block sanding by hand. It woudl take a while, but I did the block sanding anyways after milling to blend the surfaces. A good machine shop shoudl be able to mill it all in one pass (my milling machine was small). You may also wish to use 1/2" by 1" flatbar to allow more material for milling, although more difficult to weld.

IMG_0873.jpg

 

 

4. I then had the other side welded. Its important to flatten out the 1st side so the flange can be clamped to the table flat while the other side is being welded. After its welded do the same milling/grinding/sanding to this side. When its done, you shoudl have less then 1/8" warpage on the flange. Although clamping the flange to a table and welding the pan structure to it flatten it out, so dont be too concerned.

 

4. Using C clamps, clamp the flange to your stock pan, mark your holes (anyones that you can), drill them out on a drill press. I used a slightly larger drill for greater room of error. Any holes you cant mark you will have to measure using calipers etc. and hope for the best. Mine turned out well and I was able to bolt the flnage to the pan.

IMG_0886.jpg

 

Starting to look like a flange!

 

5. Get your aluminum sheared out. For the front I used 2" wide strip, while for the rear I used a 5" wide strip.

bend up all your pieces. I simply used a vice. For the 5" piece you will need to make a fixture. Patience is key here.

IMG_0901.jpg

 

6. Make the bottom pieces. Get your pieces sheared if possible. Otherwise use bandsaw for any contours/etc.

IMG_0905.jpg

7. Weld it all up. A friend did all the welding for me and did a tremendous job.

IMG_0914.jpg

 

8. My baffling. (trap doors) I later added flatbar to the top to prevent the oil from "hopping" over. Add any provisions for guages and an oil drain.

IMG_0909.jpg

 

 

Not the most complete writeup, but itll just give you an idea. Im assuming that you have above average fabrication skills. It really isnt as hard as you think.

One more thing to note, make sure you test fit the flange on the block prior to making the pan, as it will require grinding in some areas to clear the girdle and oil pump bolt. For my trapdoors, I used regular steel door hinges. Make sure yo uuse lockwashers and loctite red when fastening steel to aluminum!

I have had great oil pressure so far with this baffling!

I am using the stock windage trays that are bolted to the block.. No windage tray has been built into the pan as I didnt think it was necesary. If you think it is, thats great, build one for your motor,

Its somewhat late and I just threw this together, but any specific questions, just ask.

Good luck!

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another tip: bolting the pan to ur motor and ensuring a seal.

Start by cleaning both surfaces, the block and the pans flange. Make sure you test fit everything and are satisfied with your work. To ensure a seal, apply sealent to the pan. I used a generous amount, but don't overdo it. Now bolt the pan to ur motor usig all bolts. Unbolt it and take note where the sealent hasn't contacted the block. Apply generous amouts of sealent in those areas and bolt her back up again. Allow the sealent to cure before really torquing the bolts down. Recheck tightness after a few heat cycles.

I can almost guarentee you will have a leak free engine using this method.

There will always be some warpage when welding it up, I found up to 1/8 accepable since that's what I had, and I have zero leaks. Anymore warpage and you may want to consider buying an extra tube of sealent or having a machine shop remove the highspots from your oilpan.

 

I'm pretty sure bolting the pan to a table using all bolt holes would yield no warpage.

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Well if I hadn't had already bought the now obsolete RB Z31 sump I would be knocking at your door

The std Z31 type from Nissan cost £300 + to get it here in the uk :shock:

So that tells you what a tailor made alloy sump should be worth?

Sure if you get the price right they will sell

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oh yah...? whos intersted?

 

 

Be careful falling into that trap. James Thagard made a bunch of aluminum pans because people here said they were interested. Then only a few people actually bought them. I ended up buying the the rest of them because he sold them to me cheaper than I could manufacture them for. Basically, he was getting out from underneath the heap.

 

There's a very small market for RB rear sump pans, and established businesses that already make them. Don't spend a lot of time and money "tooling up". Keep the design, manufacture on a one-off basis, charge on a one-off basis.

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Yeah Im not really interested in producing them. To make it worthwhile I'd have to get the flanges cut and would have to get several of them to make it worthwhile. Really the hardest part is the flange. That's the purpose of this writeup to give people an idea on hot to make a one off. Bending up the pan sheetmetal and cutting them is very easy and does not take long.

Fwiw, a pan like this took about300 bucks in materials and welding supplies.

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  • 2 weeks later...
how far is it from the front 2" to the front of the 5" peice?

 

depends how much capacity you want, how far back you place the motor, how big you want your sump, etc...

ill take some measurments today.

 

No idea if thsi will work on a 280zx as I have never owned one.

 

EDIT: another thing to note, make the front part of the pan as shallow as possible to help with driveline angles yet still able to retain clearence between the pan and steering rack.

i will end up using spacers between my subframe and frame rails to obtain proper driveline angles.

im sure this is easily avoidable if you make the front part say 1 1/2" deep if it permits. measure the bottom of the windage tray to the block using verniers or blocks. id imagine youd want about 1/4" clearence between the windage tray and pan to let the oil drain out of the tray and stream into the sump.

this will slightly reduce your capacity.

you could also make the front part 2" deep and use subframe spacers like I am.

lifting the tranny up is another option, but im limited since my custom shifter for the z32 trans will hit the drivetrain tunnel.

right now im at about 5 degrees and will need roughly a 1/2" spacer or so to make it 3 or less.

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