AC Delco oil filters

[Gary S.]

There has been quite a bit of discusson on oil filters in the last few weeks and I thought I would ask the stupid question. My 72 LT1 originally used a PF-25 but I understand that the -35 will work and then I read that a 1218 will also work. Since I try to buy either AC or Wix only for my car I want the most filtering element with the best capturing media.

What differentiates the 1218 from either the 35 or the 25? Is this one of those situation where size matters? Seriously, short of me standing at the parts counter and pulling all three filters out of the box, what are the differences between the three?

Thank you,

Gary
pulling the car out of storage tomorrow in Pittsburgh. Probably calling for a freak snowstorm as soon as I do?

[Dick W.]

Re: AC Delco oil filters

Another option for a driver, PF 932, the two quart truck filter. I use this filter on our dirver. Like the extra quart of oil, especially when driving long distance on the interstate. Gives just a little more cooling.

[lyndon sharpton]

Re: AC Delco oil filters

Dick,

does that filter go below the pan are is it even with it?

[Duke W.]

Re: AC Delco oil filters

The "standard" replacement for the PF-25 is the PF-454. It's a little shorter than the 25 and has a rubber anti-drainback diaphragm, which is not an issue on vintage V-8s, but is a benefit for a horizontal or "upside down" installations.

IMO "oversize" filters provide no benefit on a vintage engines unless something inside is disintegrating.

The 454 is OE on medium duty big block truck engines, so it should be more than adequate for vintage Corvette engines that see low mileage accumulation and an annual oil and filter change.

The PF-454 should be commonly available since it fits both modern and tens of millions of existing engines going back nearly 40 years.

Duke

[Joe L.]

Re: AC Delco oil filters

Gary-----

The PF-35 size filter will work perfectly on all 68-91 Corvettes. I have been using that filter on my 1969 since about the 2nd or 3rd oil change.

The PF-1218 replaces the PF-35 and is the same size and configuration. I understand that it includes an internal anti-drainback valve which the PF-35 did not, but I've not "autopsied" one yet to learn what secrets its innerds hold. In any event, it's the fully qualified replacement for the PF-35 and it will work perfectly for all 68-91 Corvette applications. One other nice thing about using the PF-1218 in place of the PF-454 (replacement for the PF-25) is that the 1218 will hold about 1 quart of oil; the PF-454 only holds about a half quart of oil. So, if you use the PF-1218, then you need to use an even 5 (or, 6) quarts of oil. If you use the PF-454, then you risk being a half quart overfull if you use even quarts.

You can also use the PF-35L. This is a synthetic media filter. GM discontinued it awhile ago, but brought it back (due to popular demand????). It is the same size as the PF-35 or PF-1218.

There are also longer and higher capacity filters which can be used as Dick mentions. However, I don't use them on a Corvette as they usually will extend below the oil pan (some of these will extend WAY below the oil pan). The PF-35/PF-1218 filters will not extend below the oil pan.

[Dick W.]

Re: AC Delco oil filters

Lyndon, it is about flush with the bottom of the pan. I have used them for over 20 years with no problems

[Gary Schisler]

Thank you all. I know have

this information archived in my files.

Gary

[Gary Schisler]

I NOW have

a desire for editing and proper spelling.

[Paul L.]

Re: AC Delco oil filters

I use the PF-35 on my 1967 327/300. I fill with 5 liters of oil (roughly a liter is the same as a US quart).

I believe the PF-1218 with check valve was developed for the early 1990s ZR-1 C4 engine. The filter was mounted horizontally and the check valve minimized spillage at oil change time.

[Joe L.]

Re: AC Delco oil filters

Paul-----

The PF-1218 is not used for an LT5 (ZR1) application.

[Paul L.]

Re: AC Delco oil filters

Thanks Joe. I stand corrected.

[John D.]

Re: AC Delco oil filters

Gary, If you going to our chapter mini-show at Kitch's on the 8th I can bring you an AC PF-25. They have been discontinued for a couple of years. On Ebay a fellow sells them for $32.00 a case but the configuration is a little different on the bottom. John DeGregory

[Paul L.]

Re: AC Delco oil filters

John,
There are thousands of PF-25s and PF-35s in Canada available from GM dealers. I don't understand the problem.

[Gary Schisler]

Re: AC Delco oil filters

Well, if you are looking for originality and judging, the currect PF25s take a hit since they are blue (and are discontinued) and the ones that were originally on my 72 were white. Even the repros differ, although I can't remember how.

As it stands, I just installed a 1218 on my 72 about three hours ago. I like the size and the extra half a quart or so won't hurt either.

Gary