Cutlass71s

Can someone please confirm the oil capacity for a 71 350 rocket? I've researched and found it to be five quarts but when I changed my oil 4.5 came out and the dip stick showed full.

Thanks,

Pete

1978 Oldsmobile Omega

Im nowhere near an expert but my guess is that your oil filter is holding the missing oil, I believe it is a 5qt pan. I just tore down a 350 and found the filter full after draining the pan so that would make sense

Cutlass71s

Makes sense thanks

oldcutlass

Its 5 qts with a filter, however some filters hold less than a qt.

coppercutlass

People hate fram but they are ok but fram ph25 is the big filter or the stp s25 is the big one. The small pan holds 5 qts with the pan. Although i doubt its been done some people will put a 6 qt big block oil pan on the small blocks but you probably have the 5qt pan. If you go to napa and get the "gold" filter for your car you will get the big one as napa has the correct filter number under the correct application. Napa filters are great

svnt442

CC the 6qt pan is from a Toro. All of the other cars had a 5qt pan.

coppercutlass

I guess to generelize it there are 2 pans. There is a 6qt and 5 qt. Both use the same dip stick. I dunno if the toro pan was specific to it or big blocks since mine came of a bbo.

joe_padavano

Not correct. ALL RWD 1964-1990 Olds V8s take 5 qt of oil. All FWD versions (Toro and later Riv and Eldo with 307s) take 6 qt and use a different pan. The dipsticks and tubes vary by pan and by deck height.

Use a Wix or NAPA Gold filter. The Wix and NAPA Gold part number is 1049.

1BOSS83

This Wix
http://www.summitracing.com/parts/wix-51042

Is the same size as a fram ph3506, which will fit a SBO with headers with no clearance issues.

joe_padavano

It's about half the size of a 1049, however. If you need it for clearance, you need it, but I've always been able to fit a full size filter with headers.

coppercutlass

Thanks for the info joe. I always thought the big blocks had the bigger pan and assumed the toros where slightly diffrence but same shape just with a windage tray . The length of dipsticks is also good to know .

ostie13

The dip stick housing is different by about an inch on the Toronados than on other 455s. I compared the original to the new one I purchased for a 455. So when I put in exactly 6 quarts in it will read an inch over full on the dip stick.

joe_padavano

RWD pans for the SBO and BBO are the same except for two small "cheeks" just in front of the sump. The Toro pan is narrower, deeper, and has a notch to clear the RH drive axle.

This post has great photos of the differences.

coppercutlass

Joe but dont those extra cheeks add volume. I have bee running what was described as the bbo pan for years. On the bbo pan i use 6 qts and it hits on the full mark every time with both the stock dip stick in the past and the mr gasket dip stick.

coppercutlass

I may add just fwiw i have used a 350 dip stick in a 307 and when i put 5 qts in it marked right on the money. Not saying that what was mentioned is wrong ., just stating my experience.

joe_padavano

Yes, but the factory spec is still 5 qt. I've always suspected that the extra volume they provided was intended to provide a little extra clearance from the longer BBO crank throws to the oil level in the sump to avoid aeration.

coppercutlass

My post was based on my experience with the bbo pan and the stock sbo pan. What you say makes sense and im not at all saying you are incorrect. This was some great info though. That oil pan thread should be a sticky.

joe_padavano

I would expect an SBO dipstick to read correctly in another SBO. If you look at the CSM, you'll see that the BBO gets a different tube and "indicator", and Toros get yet another different set.

joe_padavano

Like I said, read the CSM. The spec is 5 qts for all RWD Olds motors. The dipsticks and tubes change based on deck height.

MDchanic

Correct me if I'm wrong, but I believe that the reason why this is so complicated is that Olds designed the RWD oil pans to bolt up to the block in the same way, and to be the same height (and thus protrude downward the same amount), but to hold their oil at different levels, while the oil pump pickup was positioned in the same place (so as not to need to create two different pumps).

The pans are designed to hold the same amount of oil at two different levels - higher up for the SB, and lower down for the BB, so that the larger-diameter BB crank counterweights don't froth up the oil, and this is why the dipsticks and dipstick tubes are different lengths for the different blocks.

So, if you have a SB, you can install a BB pan and add an extra quart of oil and the oil will be at roughly the same level it would have been at with the SB pan and 5 quarts.

- Eric

joe_padavano

I don't know that I agree with that, but I have no hard data one way or the other. I will say that tube length is a function of deck height. It would be interesting to see where the factory mark on the stick sits in relation to the pan rail on both a BBO and SBO, each with correct tube and stick.

I'll also point out that the 307 actually calls for less than five quarts of oil, but this is due to the tiny filter and the desire to lower the oil level to reduce windage losses (and eke out slightly more MPG). The pan is the same as any other SBO pan.

oldcutlass

I guess there would also be a difference in oil pump p/u tube lengths between pans.

BlackGold

4-1/2 quarts, as I recall. Thanks for correcting your earlier statement about all Olds calling for 5 quarts. I thought maybe I was going crazy.

MDchanic

No, that was my point - BB and SB pickup tubes and pumps are the same, so the pan depth is the same, but the BB pan holds more oil at a given level because it is wider.

- Eric

joe_padavano

Yeah, I don't really count 307s among "real" Olds V8s...

The bottom of the sump is exactly the same distance from the pan rail, so the pickups are the same for BBO and SBO pans. Again, Toro is different because the sump is different.

The BBO pan is not "wider". The only difference is the small "bump out" area just in front of the sump. I doubt this holds a quart.

Fun71

Same here. I have used the 1049 since the 80s on my Supreme 350 with headers.

joe_padavano

Clearly you are using those special headers that fit Supremes...

1BOSS83

No experience with A-bodies but I can say first hand that the G-body header clearance (at least in hedmans) can be a real PITA. I've had plenty of issues with "universal" pieces- starters mostly

Cutlass71s

Thanks everyone, I used the spec'd Wix filter per their website.

Fun71

Interesting as I have Heddmans on my car.

And yes, they are the "special Supreme" headers with extra clearance for the large oil filter. In the catalog look for the footnote that says "does not fit Supreme" and that's the ones!

1BOSS83

Is there any correlation between filter size and engine longevity..?

Kenneth- I've been using a ph3506 and its equivalents for 12 years. I took the car for a "professional" oil change in 03' and they returned it with the same filter..and it was leaking..When I went back I was told by the "professional" that the filter couldn't drop out because the collector blocked passage. I got my money back, wrestled the full size filter out, cleaned the collector, installed the 3506 and have been ever since. The headers and exhaust were re-done in march 14' and now you have me wondering if I could fit a full sized filter in there. That said- I'd wager most g-body owners would enjoy the vacation that is an oil change for me.

joe_padavano

Well, the real correlation should be filter size and oil change frequency. The smaller filter will clog more quickly, but if you change oil and filter on a frequent basis, that becomes a non-issue. Yes, there is also a potential issue of flow restriction, but I suspect that within reason, oil filter size is not a big driver there. Filter media is more important. The reason why I pefer Wix/NAPA Gold filters is that in a cutaway, it is obvious that they have more media surface area than the Fram filters.

1BOSS83

Joe, I'm still in the break in period of my motor and a builder at a car show suggested I place a 90lb weight magnet on the bottom of my oil filter to collect any particulate that may have been generated during break in. Thoughts?

MDchanic

No reason not to.

- Eric

olds 307 and 403

Magnet sure can't hurt and maybe get a filter cutter to see what is inside. A lot of filters have gotten even smaller as of late, no doubt better media inside. I too am running the Amsoil filter of the same size and the Mobil 1 filter for next oil change is slightly smaller again. Sure the 1049 is ideal or the next best one is the 1258, same diameter just shorter, which is what I run on my Olds powered 4x4. Both have the same Sanderson headers but the 4x4 has 2.25" exhaust vs 2.5" exhaust and way more ground clearance and room to route the custom exhaust.