Building a custom oil pan

[RallyBob]

In the process of putting together a driveline for my '72 Ascona wagon, I decided to upgrade the oiling system for greater oil capacity, oil control, and for the potential future use of forced induction. With these directives in mind, I procured an old rusty steel oil pan as my starting point. As I've mentioned many times before, I prefer starting with a steel oil pan for a multitude of reasons. For one, they are lighter than the cast aluminum Opel pans, and secondly they are far stronger in the instance of a direct impact with road debris or accidentally jacking up the car and catching the pan! While they do bend fairly easily, the important thing is that they don't shatter like the aluminum pans, so the oil stays inside the engine.

So here's the play-by-play buildup. I made the pan and baffling from 16 ga. cold rolled steel sheet (.0598" thick), which made the forming operations challenging to say the least. I surpassed my estimated alloted time by a substantial margin. I initially figured 8 hours tops, but in the end I had invested about 15 hours into it, spread out over about 7 - 8 days. Glad it wasn't a paying job! In terms of material costs I had everything laying around already except for the -10 AN steel fittings I later welded onto the drain tubes (not shown in these pics). Those cost $5 each.

I started the project out by making an oak hammer form for the pan bottom. This allowed me to radius the bottom edge very rapidly. In fact, it took me 15 minutes to make the hammerform, but only 10 minutes to actually shape the pan bottom on the hammerform! It also allows repeatability should I desire to make another pan or have to repair this one at a later date. The trimming of the pan edges and the 'fine tuning' of the rolled edges took appreciably longer, closer to an hour. I made a new T-dolly to help work the edges faster.

[RallyBob]

More of the process. The pan bottom is now trimmed to size and squared up. So I started on the sides next, forming them to the stock oil pan. I left the bottom of the pan intact until nearly the end. This allowed me to keep the bottom at the correct depth and angle so it fits the chassis right. I also made the rear section of the pan, including the tricky transition into the radiused rear corners.

[RallyBob]

In the first pic you can see how tight I got the pan addition to fit to the original pan. This is critical to get a good weld. Next I trimmed away a section of the forward (stock ) pan. I wanted to move this slightly rearward, as the new overall width would interfere with the rack and pinion mounting bolts. While the function of the pan is first and foremost here, I didn't want to paint myself into any corners! Access to all stock fasteners was critical as well. I then welded the pan assembly together, skip-welding to avoid too much heat buildup and therefore warpage.

To keep the bottom of the pan intact, and to help protect the centrally-mounted drain plug, I came up with a series of deflectors made from v-folded 16 gauge steel. They also give the pan a 'finned' appearance, and in addition to stiffening the pan itself they are the sacrificial anodes that will absorb any impacts should I run over something on the road.

[RallyBob]

I capped the ends of the pan's bottom runners for more strength and appearance's sake too.

A quick test fit shows the sump location within the pan, so I layed out the trap door pattern on the pan bottom.

Prior to fitting the trap doors and baffles, I took my trusty die grinder and some cartidge rolls and smoothed all the interior welds as well as the scaling created by the welding process. Less junk to come loose later on and get into the oiling system.

Next the fabbed up trap door setup, made from continuous (piano) hinge. The edges are angled so that in the instance they're all opened at the same time, they can't lock into each other and 'hang up'. The stock hinge pivots far too tightly, so I removed the wire hinge pin and replaced it with a smaller OD piece of welding wire. I fitted and welded the trap door assembly into the pan bottom then.

[tekenaar]

Man, you do nice work!!! . . . traditional sheet metal fabrication is an art, especially with home-made tools!

[RallyBob]

Another trap door pic.

The next step was cutting off the stock oil pan's sump area. I had previously marked the location of the new enlarged sump, so it was a simply matter of lining things up with my marks, and tack welding the new sump in place. Again, when final welding the sump I jumped around to avoid excess heat buildup and warpage.

Side baffles to prevent the oil from 'climbing' the pan during corners were made and tacked in place. Another baffle to prevent oil from shooting to the front of the pan under hard braking (the highest G's the pan will see!) was made and fitted. Note the notch to clear the oil pickup. At this point I tested the pan for leakage and it passed with flying colors...15 minutes with lacquer thinner and not a drop leaked! I also established the oil capacity, and marked where the top removeable baffle plate would be fitted, in this case *just* above the oil level.

I then bent and fitted a piece of tubing for an oil drain. It can be used one of two ways in my application: Either as a drain for an oil breather tank, or as a drain for a roots-type supercharger I *might* fit at a later date. For now it will get a -10 AN fitting welded on, and a -10 AN cap screwed onto it.

[RallyBob]

On the other side of the pan, I fitted a shorter tube that will also receive a -10 AN fitting. If I should desire at a later date, I can utilize my GT25 turbo and manifold with this pan, and it coincides with the oil drain on the turbo. Saves adding a drain to a pan in the car!

Taking a page from racecar/rallycar knowledge, I added a small loop of steel to the bottom of the pan, in order to allow for safety-wiring the oil drain plug.

I made my own block dipstick tube, it's actually secured with a set-screw so it can be rotated into position where it won't strike the crankshaft or connecting rods. I just taped some rod caps onto the crank to simulate the potential for interference with the oil pan. As it turns out my fears were warranted since #3 and #4 rod cap actually hit my top baffle plate when I spun the engine over. My solution was to notch the top baffle and bend the aluminum down a tad. Now they clear fine, as shown by a photo inside the pan as fitted to the block.

The small round hole in the top baffle plate is for the dipstick itself to pass through.

[RallyBob]

And the finished pan fitted to the block. Only thing missing in these pics are the AN fittings (already done, just no pics) and the powdercoating I will have done to it. It'll be wrinkle black probably. A bit of a shame to hide all that work under the car, but I feel better knowing the oil control will keep the engine from going 'boom' under high G cornering.

The fitting on the side of the pan is 1/8" female NPT for a temperature sender BTW.

[RallyBob]

Originally Posted by tekenaar Man, you do nice work!!! . . . traditional sheet metal fabrication is an art, especially with home-made tools!

Thank you Otto. My earliest recollection of doing this sort of work was when I was 15 years old. I made an air filter cover for my Toyota Corolla's Weber carb, based on my readings from Ron Fournier's 'Metal Fabricator's Handbook' using a hammerform technique and a ball peen hammer!

[markandson]

That is sweet Bob, I would have copied you for sure if my engine wasn't all together already. How do you know how much oil you need to bring the level to the correct height? Do you know the height inside of a stock pan?

[RallyBob]

Originally Posted by markandson That is sweet Bob, I would have copied you for sure if my engine wasn't all together already. How do you know how much oil you need to bring the level to the correct height? Do you know the height inside of a stock pan?

Yup, just fitted a stock pan to a block on my engine stand, and fit the dipstick. Added fluid (in my case lacquer thinner) until the pan was full on the dipstick (minus the filter volume). Removed pan carefully, blocked it up at the correct rearward tilt using my digital level, and then marked the inside of the pan at the correct level with a marker. I then transferred that mark to the modified pan via measurements.

[markandson]

Originally Posted by RallyBob or accidentally jacking up the car and catching the pan!

Guess what I did just before I put the car away for the winter. Fortunately it only dented my chromed aluminum pan and didn't crack it. The jack slipped off of a piece of 2 x 6 that I was using for extra height, scared the crap out of me!
I was not under the car, I was in the process of jacking it up to get the jack stands in place.

[jtb]

Wow!


Nice work!

jtb

[davegt27]

Gee wiz--- I need to build a pan for my 4AG i figure about 2020 i might get some where close to your skill level (yeah right)


nice work


Davegt27

[jordan]

As always Bob, beautiful work. No form over function or the latter, both are outstanding.

[davegt27]

in the interest of trying to learn more

what kind of tools did you use to cut metal?


thanks
Davegt27

[RallyBob]

Originally Posted by davegt27 in the interest of trying to learn more what kind of tools did you use to cut metal? thanks Davegt27

Pretty minimal tools were used, except for the TIG welder. For rough-cutting I use a bench shear from Woodward Fab (about $100), for fine-cutting I used high offset aviation shears (red and green, about $17 each). For some oddball trimming and cutting I use a 4.5" diameter abrasive cut-off wheel on an inexpensive Craftsman angle grinder (about $50 for the grinder and $4 per cut off wheel).

The hammerform I made from some scrap red oak cut out on a bandsaw, and used a 3/4" radius round-over bit on a router to get the radiused edge. The T-dollys were made from 3/4" steel bar welded to 1/4" x 1.5" flat stock.

Summit Racing sells the bench shear by Woodward Fab BTW....
Woodward Fab SPHS8 - Woodward Fab Metal Cutting Hand Shears

HTH,
Bob

[wrench459]

Originally Posted by RallyBob I then bent and fitted a piece of tubing for an oil drain. It can be used one of two ways in my application: Either as a drain for an oil breather tank, or as a drain for a roots-type supercharger I *might* fit at a later date. For now it will get a -10 AN fitting welded on, and a -10 AN cap screwed onto it.

Nice sump, as always nice fab work Bob!
Might that charger be a whipple?

[Gary]

Just amazing. Just when you think that Bob has done it all, here comes a custom oil pan.There is no limit to what RallyBob can do.

I ran into the WWBD (What Would Bob Do) syndrome the other week when I put a new water pump in my '51 Olympia. I ended up replacing the front seal and cleaning and painting everything I touched.

[RallyBob]

Originally Posted by Gary I ran into the WWBD (What Would Bob Do) syndrome the other week when I put a new water pump in my '51 Olympia.

Too funny! That is exactly what a few of my friends say about me...when they are working on a solution to a (mechanical) problem they always say 'What would Bob do?'.

I ended up replacing the front seal and cleaning and painting everything I touched.

Assuming you took a bathroom break at some point, what color did you paint 'it' and what does your wife say about it now?

[jerseyopel]

And, did you use wrinkle paint?

[davegt27]

Originally Posted by RallyBob Pretty minimal tools were used, except for the TIG welder. For rough-cutting I use a bench shear from Woodward Fab (about $100), for fine-cutting I used high offset aviation shears (red and green, about $17 each). For some oddball trimming and cutting I use a 4.5" diameter abrasive cut-off wheel on an inexpensive Craftsman angle grinder (about $50 for the grinder and $4 per cut off wheel). The hammerform I made from some scrap red oak cut out on a bandsaw, and used a 3/4" radius round-over bit on a router to get the radiused edge. The T-dollys were made from 3/4" steel bar welded to 1/4" x 1.5" flat stock. Summit Racing sells the bench shear by Woodward Fab BTW.... Woodward Fab SPHS8 - Woodward Fab Metal Cutting Hand Shears HTH, Bob

thanks Bob

davegt27

[IT Manta]

And you only made one! Bob, you are killing me

[RallyBob]

Just a little update here, pictures of the pan after powdercoating.

[Aardvaark]

Bob. Any thoughs or calculations on what the engines oil capacity will be?
Or are you just going to wait and see?