stngry63

I know that some of you use spin on oil filters. The instructions for my ZZ4 recommended an AC/Delco PF1218. Without thinking about it, I picked up a PF35L and had to go back for the PF1218. The outside dimensions are the same. I noticed that the inside diameter to be slightly different. Which one is best? Are there any other filter suggestions?

plaidside

The PF35 and the PF1218 are identical except the PF1218 has an anti-drain back valve built into it to prevent oil from draining out of the filter when it is installed on an angle. On a small block where the filter goes straight up, it does not matter which one you use.

stngry63

Thanks

7vettes

I liked K&N air filters so much that several years ago I decided to try their oil filter. Now thats all I use on my Jasper 350.


[Modified by 7vettes, 7:59 PM 10/30/2002]

JoesC5

7vettes, what's the part # of the K&N filter you use?
thanks, Joe

Mel Foye

Seems more pressure would be from more resistance to flow rather than more flow. Example, the tighter the bearing clearance the higher the resistance (pressure). Time to call in the big dogs. Mel

stngry63

With my limited knowledge of physics, I can see that there would be a pressure drop across a filter. But, I don't see how it can be used to directly rate a filter's quality. Also, is more oil pressure than needed better?
Brian

7vettes

HP-2002

Plasticman

Mel,

The pressure guage is fed oil after the filter (not before it), so any increase in pressure is due to higher flow. However, I find this hard to believe (that K&N generates higher pressure than stock). Pressure reading is controlled by 3 factors (besides others such as viscosity, but will assume that they have not changed): Total oil flow, pressure regulator in the oil pump body, and the clearances in the engine. Neither the pressure reg. or the clearances have changed by changing the oil filter. Certainly if the oil filter is more restrictive, less total oil flow and the pressure reading (after the filter) will decrease. Conversely, a less restrictive filter will potentially increase total flow and therefore increase the reading. However, my past experiences with K&N products does not bear this out (although I admit to not having tested their oil filters). Due to quantitive testing I found that their air filter products are the subject of minute increases in flow (if any) and result in practically zero HP increase (contrary to thier marketing dept. and massive advertizing promotions - plus they must be in the pockets of some magazine editors/artical writers for all the hype they get!). For the oil filter to increase flow any "substantial" amount, a pretty large filter area change needed to occur, or they increased the size of the particles it filters (which is not a "good" thing!).

I have raced and operated and torn apart many a good small block. All with AC filters. At no time have I ever experianced an oil or oil filter related failure. I'll stick with the AC thank you.

Just my lousy opinion!
Plasticman


[Modified by Plasticman, 3:20 PM 10/30/2002]

Daffy2

I don't peddle filters, and I can't recall the whereabouts of the testing that I studied, but the Purolator filter line has been found to be about the best with Fram a real poor showing. GM's line was found to be pretty good, but you have to pay their price. There are a lot of good filters out there that are "branded" (made by well known companies and sold as house brands). Scan the net for filter trials and you'll find some surprizing information. You can buy the same filter with different names at WAY different prices. And a tip: when you find the one you want at a good sale price, buy a half dozen and shelf 'em.
Daffy2