Why would you advise against the fabricated pans? I'd like to hear some more on this, where they are inferior, why they are inferior and what makes them a bad idea.

This type of pan has been used in racing applications for the last 20 years plus... and they've allowed and solved a ton of problems due to the potential design of a fabbed pan over a stamped or cast pan.


Please enlighten us as to why they are a bad idea.

Also on the top end drainback issue, have you seen the modifications that are being done to solve this as well? Holes in the lifter trays, and in some cases external drainback lines at the corners of the heads to aid in the issue.

Also... as the drainback is a problem, is this not a reason to run a pan with a substantially higher capacity so that the added volume of oil being moved throughout the engine will not result in the pan being sucked dry (hence the reason to run a fabbed pan where 8+ qt capacity is possible in a wet sump application with an aftermarket k member, without the loss of ground clearance) Or are you saying the added volume of oil being moved thru the engine is not something that can be advantageous?

 

In the aluminum LS-series blocks, the oil pan is a structural part of the engine. GM even calls it "Engine reinforcement" in the shop manuals. The welded sheet metal pans are not as sturdy as the cast pans. They also don't bolt to the bellhousing like the stock pan, further reducing their structural integrity. They also tend to leak more (speaking from experience here). With all of those welds, it's difficult to control the quality and make sure there are no leaks. If you do go with a welded pan, we recommend the higher end pans with billet rails, as they are a little stronger.

Yes, those types of mods help.

Yes, a higher capacity pan helps as well and is a good idea. Flowing more oil is good, but not if it surpasses the drain-back rate.

 

I am not sold that the pan has enough mass to it to actually keep anything more stable then a good pan with a billet rail, or in the case of a steel pan a decent think flange to build he pan off of. As for leaks... the canton ones are the only ones that I have seen that leak, the moroso, as well as a couple other higher end ones don't leak at all.

Alot of the guys are doing auto swaps that don't have any attachment to the oil pan at all, you put a Th400 or glide behind the motor, and there's no attachment to the oil pan so that's a mute point at this stage of things, no concern there becuase people have been doing these trans swaps for 10 years now and there's no proof that causes any issues at all.

As for the weld leaks... again with the better pans I have not seen one that had any issues there yet, other then the canton ones. But, that's not on the high eny by any means at least to me.

I would be curious to see, what the bearings look like in an engine, that's been in a car that has a factory pan on it for say 50 passes, then swap just the pan and pickup to the moroso stamped steel one (alum factory ls block, at say 800 crank hp power level, 7800 rpm engine) and see if there's anything that makes one think that the block is shifting more due to the pan swap, make 50 passes in it again, same oil, etc for comparison.

I am very skeptical about believing the pan is holding the block together at all... I have heard/read the same manual's you're talking about... but I'd like to see some solid proof, that the pan is holding the block more steady then a fabbed version. I'm sure that it's not with the iron block's.

 

Interesting thread, subscribed.

 

thanks for that info improvedracing

I have a catch can and they helped a ton. So your saving 1 qt after MAX full. so like 7 with the bigger filter.

 

Well im going to say right now, the stamped pans have no structural integrity/ridgidity at all. Whether or not that actually matters to the function of the block as a whole I dont know. Supposedly it does, via gm. But the cast pans are much more rigid probably 10 times as much. Ive seen the alum moroso's leake first hand. If you made an aluminum pan out of 1/4 plate and some well placed gusseting maybe it would come close to a cast pan, but cast will still hold the edge, as the casting process makes it stiffer...

 

I'm aware the casting process is making alot more robust part... but I just don't think the blocks are really designed to rely on that. There's too many pans that GM themselves put on various blocks, to say that they're all the same as far as strength.. and if it matters they would all have to have similar strength....

Follow my thinking here?

If you've had a moroso pan leak, you're one of the few. I have dealt with several of them and every one I have touched sealed good.

 

steel pan here, stock GM 6.0L block, 7xx NA plus a shot of spray. no problems so far!

seems to hold up fine. GM did their homework on these blocks.

 

If someone actually believes the stock cast oil pan is a "Structural" part of the engine assembly - put the Koolaide down and step away from the computer.


Fab'ed and Stamped pans have been used for YEARS on just about every single engine block ever designed. To top that off, LS engines with deep skirt, 6 bolt/cross bolted mains is where the structural integrity is.

Anyone that has or built one of these engines knows there is a point when the stock pan and pickup become a problem - this is usually when the 60' gets quick enough that the oil sloshes to the back, and the pump begins to cavitate - add on to this the fact that these engines feed the lifters first, you can pump a bunch of oil to the top end further exacerbating the situation.

A good high volume pan with a proper pickup is the best way to fix this problem.

 

I've seen a Moroso pan leak first-hand as well. Had to send it back for a replacement.

It's hard to say how much more the block flexes without the structural pan or what kind of effect it has, and we all know people use the sheet metal pans without any obvious problems. The guys who make girdles for these engines claim that stiffening the block increases horsepower (see http://www.dmperformance.org/ls6.html?1171930449750).

Cast aluminum pans are far more expensive than stamped steel pans. You can be sure that GM would have taken the less expensive option if they thought they could get away with it.

 

Posting this up for reference:

 

Sounds like GM kinda did it for a reason it seems?

Improved I was thinking about this issue the other day after pulling the car from the ticket booth to the pits and thought I wonder what my oil pressure is like when I'm launching? Car pulls the wheels pretty good and I know it's gotta drop when it does. I'm going to watch it, but I'll be calling you guys this winter to grab one of those baffles from you.

 

After reading that I'll bet that they did the pan to reduce noise more then anything. I don't think that you're really getting that much flex related issues with the trans behind these, I'd like to see a case where someone put an aftermarket stamped pan on and it caused a trans related issue... the T56 trans didn't attach to the pan at all so I have a hard time believing that this is doing anything in that department.

It was a noise reduction thing I'm sure of it... the engines are one of the quietest (minus the piston slap noise LOL) line's that GM has ever produced and I would say it was done more for that then anything.

Next time I talk to Steven Hodge I will ask him if he knows why the pans were cast... I know he was around Gm when the engine was in development and I'm sure if there's a reason for going with the cast pan, he will know what it is.

 

The T-56 does bolt to the pan. At least in every car I've seen. The bolt holes for it are definitely there.

I certainly don't think that using the less rigid sheet-metal pan would result in catastrophic failure. We know that's not the case; it's just less than optimal. More stress on the engine and transmission, possible reduction in horsepower, and more noise. Plus they are more likely to leak. So it's not like you're going to destroy your engine, but why invest a bunch of money in modifying a car to make it less than optimal?

The solution would obviously be an aftermarket cast aluminum pan with proper baffling and oil control. We actually have something like that in the works...

 

A couple final comments on this and I'm done with it... if the pan was such an essential structural piece of the block then:

A. why do we not see failures due to running something other then the pan that was specificially supplied with the block (example: the truck pan, corvette pan, f body pan, all which will have different structure designs can be interchanged with zero impact)

B. why is the lsx block sold by GM, with their design, not specificially state that it needs a factory GM cast pan to hold it together

C. When RHS designed their block why did they not specificially say, that they did not need to use a cast pan with their block

I can answer B and C 100%, the cast pan is not needed for any structural purpose.

As for the trans attachment to the pan I absolutely refuse to believe that attaching the trans to the pan is getting you anything as far as added strength. If this was the case the aftermarket bellhousings for every other engine type, and trans type would have caught onto this a long time ago, especially with the stresses created during drag racing. For 40 years, Th400's, Th350's and powerglide trans cases as well as the offerings from ford and chrysler were all attached to the block only. If this has been able to work for as long as it has... I do not for 1 minute think this needs to be questioned.


As for the ability of an aftermarket pan, to seal to the block, if a good gasket is used, the surface of the pan that mates to the block is flat, and the proper tq is used there's zero reason that there is any reason for one to leak. Canton ones leak, because the flange they use is too thin and it warps from the welding process, and they don't take the time to resurface the flange after welding. If a moroso one leaks, send it back they will replace it I'm sure of that.

And I'm sure.. that GM gets their fare share of cast pans that aren't right and don't seal right at the factory, or they have a procedure for checking them before they're installed... they get rejects I'm sure of that we just don't see them.


As far as casting a pan with baffles in it, go for it... just make sure it's priced less then a good fabbed pan or you won't stand a chance of it selling a whole lot. People have been around fabbed and stamped steel pans for too long to want to get away from them and go to a heavier harder to repair cast pieces... maybe I'm wrong on that but the market will decide.

 

t56 doesn't bolt the to stock pan?
in 1955 GM should have known and designed the powerglide with more bolt holes for the LS1?
a 2500hp race block, should have a note to tell you to run a cast pan for?

 

90% of modern engines use a cast oil pan to increase structural rigidity. the t56 DOES bolt to the stock pan via two 10mm bolts on the bottom of the bell, and FYI kent-moore makes alignment tools for the front cover and rear cover for a reason. and JL, they interchange without hurning structural rigidity because they're all designed by the same company to the same standards.... isnt that kind of a given?


i will say that an AL block would benefit more from the factory cast pan, for obvious reasons.

 

oddly, both mast motorsports and holley make aftermarket CAST oil pans. and both mention the oil pan as a stressed member in their product description.

 

I have the Improved racing item.
Its cured my oil pressure light popping up on my short circuit track days, my main problem was when pulling high G's around corners.
All sorted!

 

It doesn't bolt to the pan in other applications (viper, cobra)

The race block doesn't tell you do it because it's not needed.

I'm not talking about what Gm made 60 years ago... I'm talking about the aftermarket bellhousing and cases available... none of which were set up to be supported by anything more then the block.


KM, believe what you want but it's a noise thing, structure, I would be willing to bet good $ it has no regard.

And with the design of a C5 pan vs the ls f body and truck pan, there's no way that they have the same strength's in the same places. Look at the design, you aren't going to try to sell that they both provide the same support are you?


Cast, fabbed, billet 1 piece, run what you want as long as it controls the oil and holds an adequate amount you aren't going to be any worse off regardless which one you run, regardless which block you run.

If that wasn't the case there would have been issues found with this a long time ago...