1972 LS-5 Oil Pan Dimple?

[Owen L.]

Here are two pics of my oil pan. Is the dimple a factory device to aid in locating the interior windage tray or is it a scar from use? It coincides exactly with the leading edge of the tray and there are no scrapes leading into or out of the dimple like a rock or something would do. Before I call the pan clean-up done, should I leave this as factory or pound it out?

Thanks.
Owen

IMG_2491 copy.jpgIMG_2494 copy 2.jpg

[Joe L.]

Re: 1972 LS-5 Oil Pan Dimple?

Here are two pics of my oil pan. Is the dimple a factory device to aid in locating the interior windage tray or is it a scar from use? It coincides exactly with the leading edge of the tray and there are no scrapes leading into or out of the dimple like a rock or something would do. Before I call the pan clean-up done, should I leave this as factory or pound it out?

Thanks.
Owen

[ATTACH=CONFIG]97605[/ATTACH][ATTACH=CONFIG]97606[/ATTACH]

Owen------


I don't know if this dimple is original to the pan or not. However, what I do know is that this is not a Corvette oil pan. It's a Chevelle or passenger car pan. Note the side oil drain and the "depressions" on either side of the front portion of the pan. Corvette big block pans have a rear drain and do not have these "depressions".

[Owen L.]

Re: 1972 LS-5 Oil Pan Dimple?

Owen------


I don't know if this dimple is original to the pan or not. However, what I do know is that this is not a Corvette oil pan. It's a Chevelle or passenger car pan. Note the side oil drain and the "depressions" on either side of the front portion of the pan. Corvette big block pans have a rear drain and do not have these "depressions".

Damn. Well, here's adding a few more hundred to the bottom line.
Thanks for the info, even though it wasn't what I was expecting!

[Joe L.]

Re: 1972 LS-5 Oil Pan Dimple?

Damn. Well, here's adding a few more hundred to the bottom line.
Thanks for the info, even though it wasn't what I was expecting!

Owen-----


You can still obtain an oil pan virtually identical to your original from GM under GM #14091356. About 207 bucks, GM list.

[Owen L.]

Re: 1972 LS-5 Oil Pan Dimple?

Owen-----


You can still obtain an oil pan virtually identical to your original from GM under GM #14091356. About 207 bucks, GM list.

Thank you, Joe, for the comment that it's virtually identical - that's my main concern. My aim is to be visually period appropriate, not necessarily replacing everything on the car that was not made in 1972. It'll be one of the few things I can order from my local Chevy dealer; might be nice walking to the parts counter again for a change!

[Leonard M.]

Re: 1972 LS-5 Oil Pan Dimple?

Some pictures of an original for reference.
DSCN2563.jpgDSCN2564.jpgDSCN2565.jpgDSCN2568.jpg

[Leonard M.]

Re: 1972 LS-5 Oil Pan Dimple?

This one may be correct if you want to inquire (not mine)
https://richmond.craigslist.org/pts/d/montpelier-bbc-stock-chevy-oil-pan-6-qt/7091837490.html

[Joe L.]

Re: 1972 LS-5 Oil Pan Dimple?

Thank you, Joe, for the comment that it's virtually identical - that's my main concern. My aim is to be visually period appropriate, not necessarily replacing everything on the car that was not made in 1972. It'll be one of the few things I can order from my local Chevy dealer; might be nice walking to the parts counter again for a change!

Owen------


One thing that is different about the 14091356 oil pan is that it has no corner reinforcements. These never were or are now available separately from GM in SERVICE. However, there are excellent reproductions available from Corvette vendors. These do not need to be spot welded to the pan. That was a PRODUCTION convenience. The pan bolts will secure them nicely and no one will ever know they are not spot welded..

[Keith B.]

Re: 1972 LS-5 Oil Pan Dimple?

Joe they also come on some crate engines. He might get lucky and find a shop that bought crate engines and has one laying around

[Jimmy G.]

Re: 1972 LS-5 Oil Pan Dimple?

The corner reinforcements can be purchased seperately LI I think has them

[Joe L.]

Re: 1972 LS-5 Oil Pan Dimple?

Damn. Well, here's adding a few more hundred to the bottom line.
Thanks for the info, even though it wasn't what I was expecting!

Owen------


One other thing I alluded to in a previous response but did not state clearly: if you obtain a used pan you must obtain a GM #3974328, GM #3977591 or GM #14091356. Unfortunately, these pans do not usually have a part number on them although some examples of the 14091356 have the number "14095705" stamped on the bottom (this is because the 14091356 SERVICE part number is actually the 14095705 pan + 3967854 external baffle but is nevertheless known as the 14091356 pan).

1970-74 Corvette big block owners cannot use earlier big block pans GM #3872429 (1965-68) or GM #3955106 (69). These pans do not have the internal baffling position necessary for 4" stroke 454 engines but are otherwise virtually identical to later oil pans. Unfortunately, it's difficult to distinguish the baffling position difference between the earlier and later oil pans.

[Owen L.]

Re: 1972 LS-5 Oil Pan Dimple?

Owen------


One other thing I alluded to in a previous response but did not state clearly: if you obtain a used pan you must obtain a GM #3974328, GM #3977591 or GM #14091356. <snip>

1970-74 Corvette big block owners cannot use earlier big block pans GM #3872429 (1965-68) or GM #3955106 (69). These pans do not have the internal baffling position necessary for 4" stroke 454 engines but are otherwise virtually identical to later oil pans. Unfortunately, it's difficult to distinguish the baffling position difference between the earlier and later oil pans.

Thank you, Joe, for thinking of me and adding this advice. Do you know of any source that shows the internal baffle plates for the appropriate pans? Do they all look like Leonard's photo above? Part of me is just about ready to accept the over-the-counter pan you suggested early on since it looks nearly identical to the original. (If I do go this route, is the additional windage tray worth buying the mounting studs to use it?)

I've been looking on ebay, craigslist, etc. and see a whole bunch of pans but am leery because I can't trust that the seller actually knows that the true application of the pan was for a Corvette much less the years stated. It seems that if you put "Corvette" in front of any odd part it implies better parts or performance. I'm just not confident enough in my own comparison skills to know what's the right one and what to pass on.

With my engine project, I'm discovering that while the block, heads, and intake are all the correct castings and dates to the car, the starter, alternator, and oil pan are not -- haven't checked the Q-Jet yet. I find it odd that the pan was changed out because it's not an electrical item and the engine's internals are 100% factory original bearings and bore sizes. It's also had chrome valve covers put on it but that's a question for another thread...

[Owen L.]

Re: 1972 LS-5 Oil Pan Dimple?

Thank you Leonard, those photos really help with my search. Also, I tried that craigslist link but the seller never replied.

[Joe L.]

Re: 1972 LS-5 Oil Pan Dimple?

Thank you, Joe, for thinking of me and adding this advice. Do you know of any source that shows the internal baffle plates for the appropriate pans? Do they all look like Leonard's photo above? Part of me is just about ready to accept the over-the-counter pan you suggested early on since it looks nearly identical to the original. (If I do go this route, is the additional windage tray worth buying the mounting studs to use it?)

I've been looking on ebay, craigslist, etc. and see a whole bunch of pans but am leery because I can't trust that the seller actually knows that the true application of the pan was for a Corvette much less the years stated. It seems that if you put "Corvette" in front of any odd part it implies better parts or performance. I'm just not confident enough in my own comparison skills to know what's the right one and what to pass on.

With my engine project, I'm discovering that while the block, heads, and intake are all the correct castings and dates to the car, the starter, alternator, and oil pan are not -- haven't checked the Q-Jet yet. I find it odd that the pan was changed out because it's not an electrical item and the engine's internals are 100% factory original bearings and bore sizes. It's also had chrome valve covers put on it but that's a question for another thread...

Owen------


Does this engine not have an external baffle ("windage tray") now? ALL 1965-74 Corvette big blocks were originally equipped with the external baffle. So, if your engine is original, then someone removed the external baffle, likely in order to replace the pan with the non-Corvette pan you have now. I can assure you that the pan you have is not original to the engine or, at the very least, would never be accepted as typical factory production.

The internal baffling for the Corvette pan is as pictured in Leonard's photos and my photo of a 14091356 pan below. However, this baffling was not the same as the 1965-69 oil pans. I believe the only difference, though, was the that it was lowered. The external baffle was also revised for the 1970 model year. All of the 70+ pans have the top surface of the internal baffle located 4-1/4" below the oil pan rail surface. I believe the 1965-69 dimension was about 1/4" or more greater with the internal baffle otherwise configured the same.

If I were installing a correct oil pan on your engine I would definitely install the correct external baffle, GM #3967854. This baffle is supplied with the 14091356 oil pan or can be obtained separately from GM. The studs are not supplied but can still be obtained from GM under GM #3902885. Your engine would have once had these studs but they were apparently removed in order to install the non-stock oil pan.

So, why does your engine have the oil pan it does? Well, my guess would be that it's the result of "bubbaization". For some reason the pan had to be replaced. Used examples of the passenger car pan were far more plentiful than Corvette pans so that's what was obtained. When "bubba" went to install the pan he found that it would not work with the stock baffle and studs. So, he just removed those, threw them away and installed the pan.


DSCN3656.jpgDSCN3657.jpg

[Owen L.]

Re: 1972 LS-5 Oil Pan Dimple?

Does this engine not have an external baffle ("windage tray") now? ALL 1965-74 Corvette big blocks were originally equipped with the external baffle. So, if your engine is original, then someone removed the external baffle, likely in order to replace the pan with the non-Corvette pan you have now. I can assure you that the pan you have is not original to the engine or, at the very least, would never be accepted as typical factory production.

The internal baffling for the Corvette pan is as pictured in Leonard's photos and my photo of a 14091356 pan below. However, this baffling was not the same as the 1965-69 oil pans. I believe the only difference, though, was the that it was lowered. The external baffle was also revised for the 1970 model year. All of the 70+ pans have the top surface of the internal baffle located 4-1/4" below the oil pan rail surface. I believe the 1965-69 dimension was about 1/4" or more greater with the internal baffle otherwise configured the same.

Joe, I have no separate windage tray other than the baffle that's welded into the incorrect pan. (Some ebay comparisons seem to indicate this pan was used on mid to late-60s 396/427 Camaros, Chevelles, El Caminos, and Novas.) So, tell me if I'm understanding how this separate windage tray attaches (didn't get many google image results): studs (3902885) are used in place of 4 mains bolts and the tray attaches with nuts to the short section of stud extending beyond the mains housings. A little bit odd that all of my mains bolts appear to match with the dog-bone logo on them, but maybe that was just about the only mains bolts around at the time.

So, why does your engine have the oil pan it does? Well, my guess would be that it's the result of "bubbaization". For some reason the pan had to be replaced. Used examples of the passenger car pan were far more plentiful than Corvette pans so that's what was obtained. When "bubba" went to install the pan he found that it would not work with the stock baffle and studs. So, he just removed those, threw them away and installed the pan.

I trust you understand that I'm not disputing that this pan is incorrect for my car. I can certainly see a previous owner hitting a rock or something and needing to replace the pan -- or maybe just wanted the stock pan off it because it had the separate windage tray.

I noticed some stampings in the mains area of the block and will ask what these may be under a separate message. Thanks for all the time and effort you've put into my oil pan!