I've found an f-body oil pan that was modified by cutting away the section I've drawn with the red dotted line and welding in flat stock aluminum. Will this modification provide additional clearance for the stock k-member?

 

Yes it would but I dont know how excited I would be to run it as this will cut down on your oil capacity a fair amount. With the RPM these things turn oil volume is essential.

 

If those red lines are accurate, you will have PLENTY of room behind the K-member. Depending on how the notch was welded back up, you might still be a tad tight on the top...the horizontal part.

I notched my k-member to make clearance. It was a piece of cake...and didnt require too much metal removal to make room. But if you check out my pics, it might help you figure out if your notched pan will be ok.

I suspect it'll be fine. EDIT: Forgot to mention what CAM already did. Thats a really big notch...way bigger in the one direction than you will need.

J.

Page 10 of my thread...around post 491.

https://www.thirdgen.org/forums/ltx-...-again-10.html

 

Sounds like a first gen project got washed out

Assuming your pickup tube still clears the pan should fit no problem

 

How much of an issue could this really be? Unless you're at high rpm for sustained periods of time (like say a road course), are you really in danger of pumping all the oil out of the pan?

 

If you are worried, run an accu sump

 

I don't know if I'm worried or not, that's why I'm asking whether it's an issue!

Before I get involved in converting to a sump, I'll just use a stock f-pan and cut up my crossmember. What I'm trying to figure out here is what's the best/easiest solution? I found a pan that's already modified to clear a crossmember, but if I'm going to run into oil issues, I'll just use a stock pan. What I'm trying to figure out, is am I really going to have oil issues with 1 less quart in the pan?

 

I cant say either way... The LS1 is a 6 quart system. Thats a quart more than I remember my old 350 cars being. I think the cast pant inherently gains some capacity. Anyway, you could be fine.

However...if you have the means to cut/notch your k-member, and havent purchased the notched pan yet, I would probably rather clearance the k-member. Then you KNOW you wont have an issue and you can rest easy.

If you are notching for 4th gen A/C, or already have the kmember out, its a piece of cake. Even in the car its a piece of cake.

I doubt you'll have a problem with the pan...but Im not gonig to be the one to say for sure haha.

J.

 

I've never heard of any oil pan/crossmember interference before, with a F-body oil pan. Just the 4thg gen AC compressor/crossmember interferance problem. And that a Corvette LS1 oil pan won't work.

4th gen LS1 oil pans have a fitment problem?

 

Haha are you serious? We've been complaining about things being tight in that area since day 1. Some guys seem to have enough room. But more often than not, its really tight. Im betting a lot of guys dont check, or let it go with little to no room. I had to space up my trans mount just to be able to squeeze thin cardboard through that area. And even with poly mounts everywhere, Im SURE my pan was tapping the k-member under hard acceleration.

That was my biggest issue with the Spohn conversion mounts. They could have been just SLIGHTLY back, and there would have still been room for the motor/firewall clearance. Not sure if any other conversion mounts, or Spohn's latest ones, have the same issue.

J.

 

That brings me to another source of contention. I've given some thought to making my own mounts since I'm likely going to make my own trans crossmember, but then I get into potential fitment issues with the Hawks headers. Seems like moving the motor back an inch would make life easier so long as I'd have adequate header clearance.

 

Even the TGO page on LS1 swaps says it fits. Tight, but fits.... TGO LS1 into a 3rd gen. Says nothing about notching, for oil pan clearance.

Only mentions notching for the 4th gen AC compressor interference and if if you try to drop the engine in from above. Drop the K-member, bolt the LSx to it, bolt the K-member back up from below, and your good to go.

I've never been under a stock K-member/LSx 3rd gen, so I dunno.

 

Yeah I think the mileage varies with the pan clearance. Like I said. Some fit with "just enough" space. Others, like myself, had to use spacers just to get the pan off of the k-member. I know Im not the only one. Some guys put washers between the mounts and the k-member. Notching just seemed like the best way to handle the situation.

Jim: You can build your own mounts...especially if you are making your own crossmember. The headers are only "tight" side to side. Moving the motor back a tad shouldnt run you into any issues. Just measure twice before welding it all down...you know the deal.

J.

 

I notched my k-member about 3/4" or maybe 1" anyways just to be safe on clearance. I figured it was easy enough to do while everything was already out, didn't take me long to cut it out and weld in some flat stock.

 

My threads on the topic:
https://www.thirdgen.org/forums/ltx-...ppointing.html

https://www.thirdgen.org/forums/ltx-...long-last.html

There appears to be some consistency with trying to drop the engine in from above and not having clearance; and dropping the K-member, installing the engine onto the K-member, and having clearance.

 

mine fit just fine. I thought it was close so I took a hammer and beat the welded seam in a little ant that was it. I can fit thick cardboard between the pan and the k-member

 

Not sure I agree with that. Once things are in and bolted, clearances should have nothing to do with the method of install. Also, I installed my motor while attached to the k-member from below. Still had the clearance issue.

88 350 tpi formula: When you say cardboard, do you mean UPS/shipping box type cardboard, or thick paper like folder stock or the back of a package? Its in my opinion that you should have, at a minimum, 1/4" of clearance. Especially on the passenger side since the motor torques in that direction. Even with poly mounts, 320+ ft-lbs of toqure will move things around. And less than 1/8" just isnt enough if you ask me. Again..just my humble opinion on the subject.

When I first put mine together, I couldnt even get paper in there So I spaced the trans mount up like 1/8", and it allowed me to slip thin cardboard though. I spaced it up another 1/8", with the energy suspension pre-load plate, and it gave me a little more. I was able to pass a ratchet strap web through. I was STILL hitting the k-member under hard acceleration. I almost ordered a tubular unit before I decided to just yank it and notch it out earlier this year.

If someone offererd a slightly notched f-body pan on an exchange+money basis, I would have taken that route in a heartbeat. Just an inch or so would be more than enough I think.

J.

 

Not being able to drop it straight down was why I had to notch mine. I just couldn't get myself to drop the K-member and lift the body (too set in my ways, I guess).