GM 3x00

[mechanicx]

I was thinking about ways to modify the oil capacity and filter mounting on the '93-08+ SFI 3100, 3400, 3500.

Oil capacity. The 88-92 (approx.) 3.1 MPFI had a nice even 5 qt. capacity. It used the PF52 filter with about a half qtr capacity. The later SFI engines used a shorter PF47 with about a .25 qt. capacity,and an 4.5 qt. oil capacity. You can easily get a 5 qt. bottle of oil so what a pain this half qtr. is. You can put the pf52 on the SFI but if you add 5 qts. you will be overfilled by about a .25 qt on the dipstick. So I was wondering if the oil pan and real capacity on the later engine are the same and maybe you could change to the earlier dipstick and the oil would read at the fill mark?

Filter mounting. On most of these engines older MPFI and later SFI, the filter is mounted horizontal to the engine. This makes for less messy filter changes but also allows some oil to drainback. On some of the MPFI and SFI engines the oil filter mount place the filter almost or totally vertical. I've seen these type mounts in the junkyard and I'm sure you can also buy them new to bolt on to engines with a horizontal mount.

So does anyone have any ideas about using the longer PF52, the vertical filter mount and an older dipstick that reads correctly for 5 qts. fill? A nice round 5 qts. fill with a higher capacity filter mounted vertically sure sounds like a big improvement.

 

[JohnBrowning]

First my wifes 3.8 which is a better engine then the 60° V6's and larger only holds 4.5 quart's. Since her car leaks a tad I usually fill it with 5 quarts. That .5 quart over fill is not going to do any harm at all. In fact you can on most models go 1 full quart over full and not have issues if you see freq sustained RPM's or are turning a lot of G's on a track.

As to relocating you can run any size filter you have room for once you start relocating things....In theory you could run a filter designed for a 500HP commercial diesel withthe right filter adapater....It would add all kinds of capacity but to what end? I mean are you trying to increase capacity to extend oil change intervals with plain Jane oils or what? Adding more oil is not going to decrease wear metal rate of wear from the engine or extend the life of the engine. It would take a lot longer for all that extra oil to come up to temp which would hurt initial fuel ecconomy.

 

[Herz]

in theory witha bigger filter you will get more oil on start up no?

 

[mechanicx]

Originally Posted By: JohnBrowning
First my wifes 3.8 which is a better engine then the 60° V6's and larger only holds 4.5 quart's.


The 60 degree V6 is arguably the better engine in some ways, well they had a few more quality contol issues with the LIMG perhaps HG and a short time of quality issues with cams, so in practice the 3.8 tend be less troublesome overall, but the 60 degree is very durable outside of that. Yes the 3.8 uses the same filter and oil capacity but it's a whole different oil mounting.

Quote:
Since her car leaks a tad I usually fill it with 5 quarts. That .5 quart over fill is not going to do any harm at all. In fact you can on most models go 1 full quart over full and not have issues if you see freq sustained RPM's or are turning a lot of G's on a track.


Call me crazy but I'd rather be a quart low than a quart high. I am leery of being even a 1/4 qt higher than design level.


Quote:
As to relocating you can run any size filter you have room for once you start relocating things....In theory you could run a filter designed for a 500HP commercial diesel withthe right filter adapater....




It's not about relocating anything or going crazy on filter size. The adapter came stock on some applications of the 3x00 and doesn't relocate the filter, only mounts it vertically. The PF52 was used on the engines previously with a nice round 5 qt oil capacity, so my thinking was the pan didn't change only the dipstick marker level. I think you are missing my point and going off on a wild tangent. My point was you can easily find the longer filter and adapter and have an even 5 qt fill and vertical filter mount (the way I think it should've been done) using original parts that were all used at times on these engines.

Quote:
It would add all kinds of capacity but to what end? I mean are you trying to increase capacity to extend oil change intervals with plain Jane oils or what? Adding more oil is not going to decrease wear metal rate of wear from the engine or extend the life of the engine. It would take a lot longer for all that extra oil to come up to temp which would hurt initial fuel ecconomy.


I'm not sure about all that but like I said none of that is here nor there. I'm talking about simply increasing the oil capacity a half qt to the former OEM design with a nice even 5 qts and having a vertical oil filter mounting that won't/can't drainback. Sounds good to me and I thought maybe some others would like the ideal too.

 

[mechanicx]

Originally Posted By: defektes
in theory witha bigger filter you will get more oil on start up no?


I would think if you went to the longer filter if anything you would get less oil on startup, unless the filter was mounted vertically, then you would get the same or even more oil on start up. This is why I don't use the longer PF52 even though it will fit easily.

The PF52 only increase the oil capacity by 1/4 quart so your dipstick will read high if you add the extra half qt. Although I think when GM switched from 5 qts and the pf52 to the shorter pf47 and 4.5 they probably just changed the dipstick to read full at 4.5 qts (lowered the full mark slightly), so probably with the pf52 and 5 qts the oil would really not any higher than the former capacity was.

Again I don't use the longer filter because the filter isn't mounted vertically (longer fill time) don't know for a fact that only the dipstick level differs is the case and I just like my level to read dead on and not ever be higher. I'm sure that extra 1/4 qtr doesn't hurt anything and like I said is probably the same level as the former design.

The idea is here is really two-fold- 1. having a vertical filter mounting (with either filter) 2. increasing the capacity to the original 5 qts by going back to the longer filter. I thought it would be idea to have both.

 

[benjamming]

I like using only 4.5 qt for an oil change. It gives me a 1/2 quart for top-up which I usually need (& usually no more) within the OCI.

 

[artificialist]

I have worked on several newer 3500 engines that took exactly 4 quarts and used a AC PF61 filter.

 

[mechanicx]

Originally Posted By: artificialist
I have worked on several newer 3500 engines that took exactly 4 quarts and used a AC PF61 filter.


Yeah I think most of the '06+ use 4 qts and a different filter. I'm thinking now the older (pre '93?) 5 qt and PF52 engines had a different pan than the 4.5 qt and PF47 ('93-'05?). I would be fine with 4 qts. I'm not really wanting more capacity, I just dislike the .5qt stuff and like it to be even. Some cars are worse though with 4.4 qts or 4 and 5/8 .

 

[onion]

I just get oil in 1-gallon jugs for my two 3100 engines.

 

[mechanicx]

Originally Posted By: onion
I just get oil in 1-gallon jugs for my two 3100 engines.


So you just run 4qts in the 4.5 qt models? I think I'd much rather do that then go over 1/2 qt to 5.