My answer to the LSx oil pan fitment.

The truck pan fits the cross member perfectly, it just hangs too low. I'm doing this swap on the mega cheap. I cant justify shelling out $200 on an F body pan and hacking up the k-member when I have a perfectly good (and free) LM7 pan that clears the k-member so well.


This is the fitment issue. The pan hangs about 2-3" below the k-member.



It has plenty of room above and to the rear of the k-member. Fits like a glove in fact.


Here is the plan. The green is the K-member the red is where to make the cut. Basically flush with the top of the oil filter.




Rough cut using a sawzall and an 18" bi metal blade. the cut section holds approx 1 quart. The truck pan holds 6qts total. Dropping back to 5qts isnt gonna make any difference, and i'll probably pick up another qt or two with an oil cooler anyway. Onward.

Now i could weld in a new bottom, but what fun would that be? plus i dont have a tig welder. I do have a mill tho


From here the pics do most of the talking. The one thing I'll note here is the nice bosses cast into the pan these will come in handy.




I cut about 2.5" out of the sump.


Heres a better view of the bosses.


10"x10"x.5" 6061 aluminum plate. Scribed around the bottom of the pan.


Hand milled indeed. Took about an hour.

 

pretty close for a rough cut.








Scribing the inside of the sump.




sealing step cut for extra sealing capability.


nice and tight fit.

 

Drilling the bosses.


the sides have enough meat in them for a 5mm bolt. Just an added measure for holding the span. The main bolts are to be 8mm sourced from extra lifter valley cover bolts.








nearly done. Tapped the drain plug hole (12mm) to fit the OE plug.






...and there you have it. I picked up a tube of honda grey high torque gasket maker this evening, but i didn't get a chance to put it all together. The fit is nice and it should hold very well. Im planning to smooth a bead along the inside of the sump where it meets the plate. for added sealing.


Had to cut and reweld the pickup to fit the new bottom.



Interestingly enough, the Truck dipstick will still l read correctly and actually doesn't protrude into the sump at all.

In any case, there you have it. All total it cost me $29 for the 1/2" plate and $6 for a tube of sealant. Way better than a $200 pan that doesn't fit anyway. I would have rather welded it, but this is what i had to work with and paying someone else to do a job for me is out of the question.

When I get the engine installed I'll snap some pics of the clearance in the car.

 

Thats alsome, did it yourself and saved some money and a better fitting pan. Ill go this route for sure when I do my swap.

 

is there any advantage to be able to remove the bottom?can you access the oil pump?[assuming its under there]

 

I dont see any advantages, other then he saved money. The LSX oil pump is driven off the crank. So it would not help access it.. Pretty good work though...

 

I'd like to see this in the LSx swap stickys. And some in-car pics.

 

Where do I send my pan lol but very nice and creative

 

Yeah, no real advantages to having the section removable since the oil pump is behind the timing cover. Maybe to clean the pick up screen, lol but no one should ever need to do that. I don't ever plan to remove it. Like I said, it'd prolly be better to weld it, but I've been asking around and a lot of welders cringed when i told them the pan was cast. They also didn't like how thick it was and, well, the fact it was an oil pan. Oil and welding don't mix very well apparently. lol.

The only reason is saving the money. My goal is a complete carbed LM7 swap for under $1500. In all honesty the perfect 3rd gen swap pan is the Holley retro fit pan. It clears the k-member and doesn't hang low. It's basically the same dimensions as what I ended up with, for $300.

Bear with me for the in car pics, it'll be approx 2 weeks before I am ready to slip the 5.3 in. I've got a th350 to rebuild in the mean time.

Thanks for the compliments

 

We did almost the same thing on cutting down the truck pan on a 5.3 swap into an IROC. My tech took the pan to a local fabricator buddy of ours and welded the plate instead. Very cheap good fitting option for his swap which he completed for just about $2k. I don't have pics, but I know my tech does. I will let him know about the thread and see if he will post installed pics of his, until you get yours in OP.

 

That's gorgeous. I see a cottage industry here for you.

 

I'd considered doing my own, now regretting trashing the truck dipstick tube. Just need a better option for raising the screen.

 

now make some baffles to keep the oil around the pickup during high G corners... should be able to figure out where they need to be and get them tig welded to the nice clean new bottom piece for next to nothing...

 

I'd love to see some pics! I dug around on google images for some pics before I started this and came up mostly empty handed. If anyone else has any pics or details of different setups, post em up!

 

Nice work man, great mod for a budget build. Any real welder would've burned that up for you though lol. But as long as it doesn't leak who cares!

 

lol, yeah, not too many real welders around here.
Makes me think I should change careers.

Heres some more pics installed on the stand.

 

Its a good trade to get into, the shop where I'm at is constantly busy with anything you can think of. We just got a job the other day to build 10 bobsleds for team usa to practice with and the week before we finished building a food truck for some guy. Its always somthing different.


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Couldn't stand the wait on my transmission kit, so i decided to drop the engine in. Makes the car harder to push, but i need the exercise lol!

Heres some in car pics of the pan clearance.





Overall I'm happy with it. The bottom of the pan is dead even with the k member. The camera angle is a tough one, especially with the engine hoist in the way.

 

Might I suggest button-head allen bolts?

 

I actually concidered countersinking the holes and using a tapered head fastener, but the drain plug would still be hanging down no matter what I did. In any case if I drag the bolts at all, I'm probably driving where I shouldn't be. :P

 

Nice engine you have there!

 

Thanks, Dakota!
When I cut my pan yesterday afternoon it came out at 6.25" deep with no plate for the bottom, so I debated ground clearance versus sump capacity versus center of gravity for several hours, and decided to glue on a plexiglass plate and see where 4 quarts of food-coloring-water puts the depth. I want to cut more, but I need at least 4 quarts, and I need all of it to stay below the windage tray (when the engine isn't running, of course.)

 

Why not put 4-5 qts of water in it with it removed?

 

Of course. Just like that 28-page sticky on LS1Tech.com, except they forgot food coloring, so their 5-quart results are far more difficult to see than their 4-quart results. Took me an hour to skim all 28 pages. And I have the plexiglass, but have not yet purchased the aluminum plate. Pics in my thread soon.

 

Thanks! Looks better right side up for sure. :P



I saw your build thread, you can cut more, but there's really no point to cut it off any higher than the lowest point of the oil filter or much higher than the k-member itself. Know what I mean Verne?

You could relocate the filter i suppose, but the K-member would still be the lowest point. Ideally, you would want to test fit your engine and oil pan on the mounts you are using to get it just right.

If you do end up cutting down to the 4qt range I would recommend running an oil cooler. Less oil cuts down on the thermal capacity and the oil will likely run too hot even with a stock engine.

 

Overall I love the idea, but if there is anything I would do differently if it was my own, it would be to get rid of all of those bolt heads hanging down. The bolts that attach the bottom plate to the pan could be counter-sunk, and the drain plug either repositioned to the back or side of the pan. Having those where they are makes them vulnerable. The pan on my motor has the drain plug smack on the bottom, and I hate it. I've caught it on a few things, and I'm lucky that I didn't rip it right out of the pan.

On that same theme, I'd probably consider tapering the bottom of the pan or at least adding some sort of chamfer or roundover on the front edge.

 

I imagined making a drain valve (sorta like a gate valve) built into the plate and such but I was wary of leaks. Going into the side, even with the 1/2" plate, there's not enough meat to get anything bigger than a 1/8"npt plug unless the plate was welded. That also worried me with leaks and the durability of the plug itself if it were so small. It would definitely be better to tuck the bolts if we could find a good way to do it.

I'm interested to see where cosmick takes it.

 

im guessing that didnt work as planned since i see no updated pics lol i would have just spend the 200 but A for effort

 

im guessing that didnt work as planned since i see no updated pics lol i would have just spend the 200 but A for effort

 

The one i made worked flawlessly. Not sure about other folks adventure. Drove it for a year and a half with zero issues. Finished the car and sold it last year.
$200 for an oil pan is highway robbery, especially since it doesn't make the car any faster.

 

No way man that's awesome I'm glad to hear it worked I just was looking forward to some pics in the update I got a question I'm doing a 5.3 lm7 in my 87 iroc using the factory truck harness from the motor I want it to look sexy I was looking at ls1 fuel rails injectors coils and intake bit wasn't sure if anyone has done this I'm sure they have but I'm on a budget wanting best bang for my buck

 

Too bad you're not in West Michigan. I know a good welder who would have welded that (without cringing at it being cast) and probably would have cost well under $100.

If you want to find a welder who is good at cast aluminum, look for an aluminum foundry near you and check with some of their guys. Most aluminum foundries have welders that can weld cast aluminum for the sake of salvaging castings with porosity or leaks. Common practice and they're usually damn good at it. And I'd bet that some of them might even do it for a case of beer!

 

Mine turned out great, but I moved on to fabricating my own from 1/8"-thick mild steel for the vertical parts, and 1/4" for the horizontals. Having completed that, it ended up not being much cost savings, it cost more than modifying the truck pan, but I was able to make it so I can fit the truck intake in my '94 Camaro with the 3.4L K-member. I haven't yet done the swap to prove it, but I'm getting there. Anyway, DIY beats ordering a finished product.

 

I basically did all that you stated but I went with a new GM fbody oil pan, Windage tray, dipstick and pickup tube with gasket and bolts for less than $250. I wouldn't have hesitated to modify the truck pan but since I run a racecraft moly Kmember I have the clearance anyways.

I used eBay LS1 billet fuel rails and made some fuel rail brackets for the stock truck intake. I also use LS1 72lb Bosch injectors from FIC with the EV1 to truck harness adapters.

Best bang would be to get the LS fuel rails, and some reworked reflowed truck injectors so u don't need the harness adapters even tho they are super cheap anyway. I got the injectors new, genuine Bosch, flow matched and the harness adapters for alittle less than $400. You can get aftermarket Billet LS fuel rails with the correct brackets off eBay for like $100 compared to the $30-50 for just the LS style. The guy has the truck brackets made so he charges a lot.

 

How come none of the pics will load ?

 

Because Photo bucket pulled a bait and switch.
They had everybody using them for photolinking and then they changed their policy so to link photos required you to pay for an expensive(!) upgraded account.

 

FWIW eBay is now selling new fbody oil pans for $99 shipped, China but the casting is better than my GMPP fbody oil pan. Inside looks fantastic and I have one bolted to a motor right now. I cut the stock truck windage tray and picked up a new GMPP pickup tube and slapped it on for $140. The filter is different than my new fbody GM pan but I believe it Takes the original 98-02 ish fbody oil filter and not the new style they run now.

 

That's good to know, thanks for posting.!