Deeper oil pan a good idea for off road?

[mrgoodwrench]

My stock 350tbi oil pan gasket is leaking. Im going to have the oil pan off and was wondering if i should replace the oil pan with a deeper one or something while its off. Any recs i do notice that when off road ideling along in 4low at steep angles the oil pressure is pretty low probably normal but still worries me.

 

[ktmoutfront]

I've ran mine standing verticle on its side while winch lines were being ran. No big deal.

 

[mrgoodwrench]

I've ran mine standing verticle on its side while winch lines were being ran. No big deal.

So keep it stock is what your saying?

 

[ktmoutfront]

Yep. If you have it off, check the pump pickup is seated well. If you have not had any issues in the past, it should be good.

 

[mrgoodwrench]

Good to know. Pumps pretty solid on thease or should i replace it while im in there? The engine has 268,000 miles

 

[ktmoutfront]

There ate pros and cons to doing that. I always do.

 

[mrgoodwrench]

Other than work and money what cons?

 

[ktmoutfront]

Did you get it seated?
Is it a good pump? Even new, some are bad.
Some people claim pushing more oil with a new pump will wipe out the bearings. I never understood that reasoning.

What does the inside of the engine look like? Have you pulled the valve covers?

 

[mrgoodwrench]

Have not pulled anything yet was going to have parts ready first.

 

[dyeager535]

Low oil pressure is most likely either engine clearances growing (which is normal) or a weak pump spring. This assumes however you are reading pressure is correct. Repeatability is more important than accuracy IMO, but both are nice.

The oil pump spring does wear out, and is replaceable. Can't hurt to replace the pump, but unless something crazy happened to it (junk running through it) it's probably ok. Can always disassemble and check the rotors, there is no gasket or anything.

I ran a 5 qt pan, because why not. More oil, likely to run cooler, more margin for error, etc. Summit had a relatively inexpensive pan, sealed fine. Used the torque spreaders that came with the GM crate engine though. Even with a 5qt pan and engine oil cooler, it was pretty easy to get the oil up to 250-260* with ~32* ambient temps on the freeway and lower speeds up dirt roads...no clue what the temp would be in hotter conditions, or without cooler, or lower capacity pan.

Do I think a 5qt pan is necessary? Nope. Plenty of small blocks turned out with 4qt pans that live long lives. Will it hurt? Nope. But then you have to consider a different oil pump pickup, and at that point may be looking at a complete pump and pickup. The Melling M99 HV-S was the pump recommended to me for low RPM engine loading, so far it's been fine. Should have stuck with the higher pressure spring it came with though.

 

[Joel Wilson]

The more oil you have, the cooler it is going to be. The cooler the oil, the longer it lasts. Your rig already has a cooler so you shouldn't have to worry about that part. My 400 didn''t have a cooler so I had to add one which sent me on a rabbit trail, but in the end it has worked very well and my engine temps overall are cool (10 to 20 degrees above thermostat temp) and this is when its 110 outside.

If I were you, I would replace the pump while you are in there with a high volume Melling. Can't go wrong with that setup. I would also look into a new pan with some baffles or trap doors in it. supposed to help keep the oil from sloshing around too much during hard acceleration/deceleration or hard wheeling. With my old pan, I did notice some oil pressure fluctuations, with the new Moroso pan, I have not. If you want extra capacity, you can get pans with kick outs to the side so that it doesn't affect ground clearance.

Also, keep in mind that you can add oil capacity by going with a 2 qt oil filter in some cases.

 

[bp71k5]

I wouldn’t recommend switching to a high volume pump. I’ve read about several issues with them and a relatively stock engine doesn’t need it. If you do use it, then you need to watch out for blow by and other issues that pop up with higher oil pressure.

deeper oil pan might make clearances around the axle a bit tighter if you don’t plan for it. Crossover steering being one potential thing to watch.

 

[dyeager535]

Eh, most everything I've read that's fairly modern says the high pressure/high volume pumps have pretty much zero downsides. Sucking the pan dry is false (paraphrasing, not my words), excessive power consumption or deflection of the distributor was overblown, outside of those, I think the only real question is if you need or simply want something else.

The way I look at it, over time an engine IS going to lose oil pressure from normal wear and tear (plus fluctuations due to oil temp). I have my own separate reasons to run HV/HP, but generally, if you start out with 70psi and lose 3/4 of that pressure, you'd still be seeing more than the stock (30psi IIRC) pump is after losing half it's rated pressure. I consider things like low RPM, high load conditions, not just unloaded RPM vs PSI, which is the standard measure...but that doesn't work when I'm dragging a 5000lb vehicle over an obstacle at 600RPM.

But again, losing half the rated pressure occurs after how much use and abuse and miles? Quite a few.

 

[centexk5]

I wheel with a stock pan in 95-100* heat with an engine that makes 2-3psi when hot and only about 25-30psi at 2500-3000rpm. No oil cooler either. No weird noises or metal in the pan. Compression check recently came back at 150psi across the board. Point of the story, nothing wrong with the stock setup unless you just want to upgrade. My 383 I'm going with a 6qt pan and high volume pump but I'm also going to be making significantly more power and spinning significantly higher rpm than my current engine.

 

[Joel Wilson]

I wheel with a stock pan in 95-100* heat with an engine that makes 2-3psi when hot and only about 25-30psi at 2500-3000rpm. No oil cooler either. No weird noises or metal in the pan. Compression check recently came back at 150psi across the board. Point of the story, nothing wrong with the stock setup unless you just want to upgrade. My 383 I'm going with a 6qt pan and high volume pump but I'm also going to be making significantly more power and spinning significantly higher rpm than my current engine.

I have a 400 so I took all the horror stories about overheating and did the very best I could to make sure I am keeping my engine as cool as possible. I am also putting out 415 to 425hp which is far from stock and this really shouldn't be that far from your 383 and I could see the argument about HP and maybe even HV pumps. Even a new stock pump is going to be an improvement over an oil pump with 250k miles on it. There's a reason every single engine made now has an oil cooler and it has to do with longevity whether it is with capacity or with cooler temperatures. And you can go with more capacity without sacrificing ground clearance. 250k miles on his engine and he still has another 100k miles left if he plays his cards right. Parts prices are all going up across the board and you can pay a little now or a lot later. 200$ now and the OP can make sure he gets another 100k miles out of that engine.

 

[bp71k5]

I have a 400 so I took all the horror stories about overheating and did the very best I could to make sure I am keeping my engine as cool as possible. I am also putting out 415 to 425hp which is far from stock and this really shouldn't be that far from your 383 and I could see the argument about HP and maybe even HV pumps. Even a new stock pump is going to be an improvement over an oil pump with 250k miles on it. There's a reason every single engine made now has an oil cooler and it has to do with longevity whether it is with capacity or with cooler temperatures. And you can go with more capacity without sacrificing ground clearance. 250k miles on his engine and he still has another 100k miles left if he plays his cards right. Parts prices are all going up across the board and you can pay a little now or a lot later. 200$ now and the OP can make sure he gets another 100k miles out of that engine.

I’d definately agree a new oil pump would be a great idea for original poster. Just not sure there’s a benefit to high volume or pressure.

 

[dyeager535]

I’d definately agree a new oil pump would be a great idea for original poster. Just not sure there’s a benefit to high volume or pressure.

At 250k+, bearing wear is a given. I'd hate to throw a stock pump on there and have the same oil pressure I started with, and then want it to run another 100k, especially given conditions that melling specifically recommends a HV/HP pump for. More pressure and volume can't do anything but help. If replacing the pump anyway, I can't think of any reason to not bump the pressure up. It's not like a better pump reduces reliability, and if the cause of low pressure is bearing wear, a stock pump will do nothing to resolve that.

 

[bp71k5]

At 250k+, bearing wear is a given. I'd hate to throw a stock pump on there and have the same oil pressure I started with, and then want it to run another 100k, especially given conditions that melling specifically recommends a HV/HP pump for. More pressure and volume can't do anything but help. If replacing the pump anyway, I can't think of any reason to not bump the pressure up. It's not like a better pump reduces reliability, and if the cause of low pressure is bearing wear, a stock pump will do nothing to resolve that.

What’s the rule of thumb for a GM small block oil pressure requirements, was it 1psi for every 100rpm? If the oil pressure doesn’t meet that minimum level anymore, I could see how bumping it up might help, but that would also point to a much bigger problem wouldn’t it?

A couple possible downsides are more oil up to the valve covers which gets pushed into the cylinders and blown through the PCV into the intake, and also any leaks that exist will likely get worse. A higher pressure pump may not be a problem but if it does, tearing things down again to fix it wouldn’t be fun.

 

[dyeager535]

Usually hear it as 10psi per 1000, but six one way, half a dozen the other.

I've got a crate L31 with a 50psi pump. The engine has absolutely lost oil pressure (hot, at idle) in the maybe 2-3 years I've driven it, and that's not a ton of starts, and at best 10k miles. As bearing clearances grow, pressure is going to drop, no question. Granted, the pump spring wearing out COULD be a factor. But without testing the pump outside of the engine, there is no way to know if it's the spring, bearing clearance, pump, etc. For $40-50 (well, years back) just going with a new pump would at best help with either issue, at worst show no appreciable change.

I certainly don't know at what point no amount of oil pressure will stave off an engine dieing, at 250k miles I'd certainly assume an engine would be on borrowed time. It might go another 100k plus, or it might go 10 feet.

A couple advantages of the HV/HP BBC derived SBC pump melling recommended, is that it's got 7 vs 5 teeth. At lower RPMs the oil pressure output is more consistent. Not only that, when lugging the engine at around idle RPM, oil pressure drastically drops. Obviously the goal is not to stay in that area of engine speed, but it's unavoidable at times. Dropping from 45psi to 20psi, at least the engine is still getting fed a decent amount and pressure of oil...if I start with 30psi and lose the same 25psi under identical conditions, now I'm below the rule of thumb for pressure. Again, my experiences and conditions, they won't be the same for everyone. A manual trans exacerbates this issue.

Oil in the valve covers isn't under pressure, and there should be no pressure in the crankcase with a properly operating PCV. From all fairly modern references I've seen the drain back from the heads of hot engine oil is near instantaneous. I don't see how an HV/HP pump would cause issues, worn valve guides/seals will allow oil into the combustion chamber, oil pump has no bearing on that issue. Even with more oil flowing, the PCV pickup is baffled. I've never heard of anyone consuming more oil because of a higher pressure pump on a modern small block with a stock baffled PCV setup.

 

[centexk5]

I have a 400 so I took all the horror stories about overheating and did the very best I could to make sure I am keeping my engine as cool as possible. I am also putting out 415 to 425hp which is far from stock and this really shouldn't be that far from your 383 and I could see the argument about HP and maybe even HV pumps. Even a new stock pump is going to be an improvement over an oil pump with 250k miles on it. There's a reason every single engine made now has an oil cooler and it has to do with longevity whether it is with capacity or with cooler temperatures. And you can go with more capacity without sacrificing ground clearance. 250k miles on his engine and he still has another 100k miles left if he plays his cards right. Parts prices are all going up across the board and you can pay a little now or a lot later. 200$ now and the OP can make sure he gets another 100k miles out of that engine.

Not saying anything against added capacity or cooling. Just saying stock will work just fine unless you just want to or have reason to such as higher power or higher revs.