Oil pan capacity and dipstick level

Mopar Big Block Talk
Post Reply
mojo
Posts: 732
Joined: Wed Nov 22, 2006 3:41 pm

Oil pan capacity and dipstick level

Post by mojo »

I need to get the oil level in the sump of the 383 in my C-V8 MkIII correct, and this is causing me problems - hopefully someone can help.

The problem is that the sump that was fitted to my car does not seem to be correct, and was too badly dented to be economically repaired so... I replaced it with a new one. The problem is that I don't know the nominal capacity of the new pan (I can't ask the supplier as I bought it several years ago), so I can't see an obvious way to get the oil level right!

If I measure the total capacity of the oil pan itself (i.e. fill it right to the brim) I find it takes almost exactly 10 US Quarts (20 US Pints) - so I think I can infer from that that the "nominal" capacity is measured to some other point than the top of the oil pan!

So the question is: does anyone know what level relative to the bottom of the block the oil level should be?

[Before someone says "why not just fill it up to the level shown on the dipstick?" I have no confidence at all that a previous owner has fitted the correct dipstick for the car!]
User avatar
slotcarone
Posts: 1662
Joined: Sun Aug 29, 2010 1:38 pm

Re: Oil pan capacity and dipstick level

Post by slotcarone »

My only suggestion is get with an owner of a similar car and compare the dipstick and tube. If it is the same as yours then it's probably original. If so then you can just fill to the proper mark on the stick. Is the pan you installed a stock replacement pan? The Mopar engines usually took 4 quarts in the pan and another quart with the filter change. :)
1972 Interceptor III
133-5612
RichardGibson
JOC Scotland Rep
Posts: 164
Joined: Mon Apr 29, 2019 11:47 am
Location: Inverness

Re: Oil pan capacity and dipstick level

Post by RichardGibson »

Hi Mojo
Perhaps I am missing something here but could you not find out the required engine oil capacity for your CV8 Mk3, it should be given in the handbook.
If you have not got the handbook then it should be the same as the early Interceptors, I believe.
When you know the correct volume of oil for your engine, fill the engine, with the sump on, with the correct volume of oil, leave it to drain down, then see where the level is on the dip stick.
I suppose then that if the oil levels are matching the dip stick marks then all is OK as you know you have the correct quantity of oil in the engine.
If the levels do not match the marks then either you have a different volume sump or an incorrect dip stick, easily checked against a similar dip stick.
regards
Richard
mojo
Posts: 732
Joined: Wed Nov 22, 2006 3:41 pm

Re: Oil pan capacity and dipstick level

Post by mojo »

slotcarone wrote: Sun Aug 15, 2021 12:43 am The Mopar engines usually took 4 quarts in the pan and another quart with the filter change.
I know it's a dangerous thing to rely on Ebay listings (because often people use stock photos which don't actually correspond to what they are selling) but visually the oil pan I have is the same as the one in this listing:

https://www.ebay.co.uk/itm/264848285877/

That listing describes it as having a 5 Quart capacity, so I guess that means that I should have to add an additional Quart to the quantity that the Jensen handbook states?
User avatar
slotcarone
Posts: 1662
Joined: Sun Aug 29, 2010 1:38 pm

Re: Oil pan capacity and dipstick level

Post by slotcarone »

I would put 5 quarts in and start the engine to fill the filter. See where the oil is on the stick. If it shows a quart low then add a quart. :)
1972 Interceptor III
133-5612
mojo
Posts: 732
Joined: Wed Nov 22, 2006 3:41 pm

Re: Oil pan capacity and dipstick level

Post by mojo »

If I know that I can trust the dipstick then the problem becomes trivial.

I know for sure that the sump on my car was not original, because a previous "restorer" had crudely chopped holes in its internal baffle so that the pickup would fit through - but whether that's because he fitted a non-original oil pickup I don't know. This solid evidence of serial bodgery is the reason why I can't trust the dipstick.

So, in the absence of anything reliable to work from, I should, perhaps, focus on figuring out whether the dipstick is original, by simply measuring it...
mojo
Posts: 732
Joined: Wed Nov 22, 2006 3:41 pm

Re: Oil pan capacity and dipstick level

Post by mojo »

Dipstick duly measured:

Length from the shoulder that sits on the end of the dipstick tube to the "Full" mark is 520mm, and length to the "Add" mark is 535mm.

Would someone with a standard 383 be so kind as to measure theirs and confirm that this is the correct dipstick? I doubt there would have been variation within the 383 engine variant but, in case it makes a difference, this is a '66 car, so the engine itself was probably manufactured in either '65 or '66.
mojo
Posts: 732
Joined: Wed Nov 22, 2006 3:41 pm

Re: Oil pan capacity and dipstick level

Post by mojo »

Having measured the brimmed capacity of the original (but not factory original) sump, it now seems to make sense. The brimmed capacity of the original is 9 US quarts, and the brimmed capacity of the new oil pan is 10 US quarts, so it seems reasonable to assume that the original has a "nominal" capacity of 4 US quarts and the new one is a 5 US quart pan.

This makes sense because if you assume that the oil filter takes roughly 1 litre of oil, the conversion to UK pints gives a total capacity of 8.42 UK pints - which is almost exactly the capacity specified in the handbook.

Doing a similar conversion based on a 5 US quart pan yields a figure of just over 10 UK pints - so that is what I should expect to have to use in mine to get it to the "Full" mark on the dipstick.
Post Reply

Return to “V-8 Engine Tech”