Remote Oil Filter to Cadillac Flathead

I got me a new Moon remote finned aluminum oil filter at the Portland swapmeet this year to run on my flathead, but since owning it I have been told it may not work all that well with (346 Cadillac) flathead oil pressure etc.

Can anybody fill me in on the possibilties whether it is worth using or will it be a dead loss!

 

331 OHV engines just had a slow flow filter, fed off an oil galley and dumped back into the block. you can probably find a 1/8 pipe plug that closes off a galley somewhere on that engine, or tee off an oil sender unit. better than nothing.

 

It is one of these filters, which is built for a more modern engine, but I was hoping to use it on my flathead!

 

Where are the experts please?

 

On GMC motors and Packards you follow the oil from the pump and find a place where you can tap into the block and rerout the oil through the filter. On Jimmeys it's easy. On Packards not so easy. On Cads I have no idea, but you prettymuch need the engine dissasembled to do it.

 

It seems the point is being missed on my question.
I am OK with how to run my oil lines to and from the filter.

I am concerned about how the flathead oil pressure will cope with a modern oil filter.
Will the low oil pressure of my flathead be able to run thru a new style filter.

 

I'm really not sure who's missing the point here. While you may be OK with how to run the lines to and from the filter, you also need to be OK with how to run the lines to and from the engine, and what needs to be done inside the engine. RichFox is correct in that you DO have to tap into the block and reroute oil to the remote filter. The flathead Cadillacs did not originally have an oil filter, at least none that I've seen, maybe later models did. And chances are if they did, they were the low flow type mentioned above by John Walker. I wouldn't worry about the pressure, really doesn't take that much to push oil through a filter. Mine carries 35psi at idle, so these motors don't exactly have "low" pressure. Make sure you use a filter with an internal bypass. The following two pictures show how I did mine.

The second picture shows where I plumbed into the block to get at the oil feed galley. Note that you have to install a plug inside the galley right after where you tap into the motor, otherwise you'll still have a path for the oil to go from the pump directly to the motor. You do want full flow filtering, correct? I put my plug into the vertical galley that you can see just above the pipe elbow, left rear of the engine. Normal flow is from the pump, up this vertical galley, to the long horizontal galley that runs the length of the engine. Plugging this vertical galley forces the oil to go through the filter. In the first picture it shows the other end of the long horizontal galley along the left side of the engine. The filtered oil is going back into the horizontal galley from the front of the engine. Easy enough to do, if you know what you are doing.

 

And that's what's called doing it right. Replacing the stock bypass partial flowfilter with a new throw away type of filter is almost a waste of time. IMHO

 

I think the question is if there's enough pressure to pull the oil back out of the filter,
since both in and out are on the top of the canister.

The older filters pushed oil into the side of the canister,
and mostly gravity funneled it down back into the block.

They also used really thin lines/hose, like brake line.

The weaker flathead oil pressure probably won't be enough to push or pull the oil through the larger oil lines on the new style filter,
not with the amount of oil it was designed to filter anyway.

TP

 

The pressure drop across a normally functioning oil filter is on the order of 1-3 lbs. If it's a dirty filter, the internal bypass will open around 8-10 psi.

Oil will flow through large lines easier than small lines.

If the engine doesn't have enough oil pressure to "push" the oil out of the top of the canister, then installing a remote filter on this particular flathead should be way down the list of things that need to be done to the motor.

 

Well, I guess we are getting to the bottom of my problem.
Here below is a pic of the Cadillac oil IN and OUT points I have on the engine, I am not using the block in the pic but it is similar on the block that I am building.

It is starting sound like running the new style finned filter is possible but more for what looks I want, rather than anything to do with efficiency. Sounds like I maybe better off resurrecting the old Cadillac gravity flow unit.

Sorry for any confusion, but I just assumed all blocks had the oil points fitted like mine.

 

Interesting, neither of mine (1940 and 1946) have that boss on the timing cover. What year motor is the one in the picture?

One thing to be cautious of is letting too much oil flow through one of those "gravity" filters, especially if it's plumbed with the two lines shown in your picture. Some of those fittings look like they might have come from the hardware store, so not sure what you've got is a factory-plumbed setup. Could well be, it's just that I've not seen one like that. Nonetheless, it appears that those connections could be used for a low-flow filter system. Please note that the fitting to the right is directly into the main oiling galley, and any oil diverted from it through a filter will rob the motor of oil. Most of the "gravity" filters had a restrictor type orifice which let a metered amount of oil go through the filter, to insure that only a small amount of the oil is actually diverted to the filter. If not, the pressure gauge may lead you to believe you have low oil pressure and a worn engine, when in fact it is a symptom of an improperly configured filtering system. The good news is your motor has appropriate connections, and you could use your recent purchase as a low-flow filter, but you'll need to make sure that you limit the amount of oil that flows to it.

Oh, and throw that Fram away!

Good luck with it, I love the old FlatCads!

 

Hey thanks guys, I believe that engine to be a round 1942 but it also has a different exhaust manifold which exits from in front of the carby and to a twin pipe system from the looks of it. I dont have the manifolds at home to take pic's of but I was thinking that this engine may have been a military unit. I have several years being a 1937 and 1938 models but this is the most modern and complete.
The heads are car style and the markings indicate 1942 era, but who knows, if it was from a tank it would have different heads easily identifiable but swaps could have been done long ago.
Thanks for the Fram advice any idea what filter could be most suitable?

 

Here's my 1940 block, It maybe at one time has run a filter? I don't know
for sure.

 

Nice clear pic, thanks, your engine has what looks to be close to a factory set up.
You will note the timing cover long bolt which is the return entry for the filtered oil.
I am making an aluminum timing cover and have installed a thickened area on the side of the cover to screw an entry line into.
Thanks for your contribution.

 

The early OHV engines with the low-flow filters actually has a second oil pump (low pressure) that fed the oil filter. You may be able to take a 331 pump and add the low-flow 2nd pump to the bottom of the flatty pump.
Since your engine is already plumbed for a bypass filter configuration, I'd probably just use it that way, but your restrictor orifice size is going to determine how much oil pressure it costs you, so I'd ise something really small (less than 1/8", probably 1/16").

 

Very nice thanks for response

So... this is the return line? the out-line then must be on the driver side rear? mine has a 3/8-24 hex bolt blocking it off. I'm trying to figuere what
this stuff is. On my fuel pump which needs a rebuild, there is a vacuum line coming out of the lower section, the line runs up over to the center back of the block to nowhere...was this vacuum for the wipers only ?

any help will be greatly appreiciated, I want to get the motor running on
the stand, tune-it then put it the model a. maybe I should start a new post? Ken

 

Fifty,
I just read your post and though I didnt put one on a Caddy, I put one on a flatty straight 8. I tapped into the block in line with the cam area[there were taps all along there] and proceeded to rape one of the lifters of proper oiling. I now have a slight tapping because of lifter loosness. Be careful where you tap in for the feed line. steve

 

Ken, from what I know the bolt at the return point from the oil filter had a collar around it and the bolt was drilled hollow and the oil ran thru the bolt, this was because the oil filter stuff was added and it saved drilling any holes, just as the exit point to the filter is picked up out of the end of that oil gallery running thru the drivers side of the block.

As for the line from the gas pump, I am not sure as I dont and have never owned a Lasalle or Cadillac of this period. I do have fairly complete engine out back that I could check out later during day light.

Keep posting or PM me and I will answer any questions and I will tell you I dont know if I dont know rather than stringing you along with guessing.

 

Yes you are correct in that department, with these low oil pressures and playing with add on filters it seem alot of damage could be done in a very short time.

That is why I originally started this Thread as I was feeling kinder uncertain and figured that put our heads together something good must come out even if it is info for somebody else on their engine project.

I have seen several Cadillac flathead engines now with filter lines and they all seem to run in and out in the same positions so I feel a little more confident about that stuff, but sure pipe sizes are important and I still am not settled on that yet.

I want to do it once and do it right. That 2nd pump idea is interesting and I will ask around locally to some OHV caddy guys I know.
Thanks, Russ.

 

I think you are thinking of the fuel pump. Most high end cars with vacuum powered wipers had a vacuum pump on the bottom of the fuel pump, usually referred to as a 'dual diaphragm pump'. It looks like 2 fuel pumps sharing a mounting boss and arm. In some cases, the vacuum from the pump also powered the thermostatic louvers on the front of the radiator (30s Cadillacs and such), and other things on the car.

I have never seen or heard of a vacuum pump piggybacked on an internal (inside the oil pan) oil pump. The very first ('49-mid '50) OHV Caddies had no oil filter. The external dealer-option filter I have seen was plumbed off of the oil pressure switch if I remember right, which is a nice idea, because it is after all of the stuff that needs oiled. It had what looked like a poppet valve in line, so oil would not go to the filter if that bleed off would drop the pressure below the spring pressure of the valve. Neat idea, but probably not reliable over lots of miles. Anyway, when they first made the oil filter standard equipment, they added a second, smaller oil pump piggybacked on the main oil pump (essentially the same as the early pump and the later single pump on the full-flow filter engines), which took oil from the same pickup tube, but pumped it out through a small copper line to a fitting in the block, through it's own passage drilled through the block, to the external copper line feeding the filter. The 51-53 factory service manuals should show it on the 'oil system diagram' drawing. If I had one here, I would scan it for you. My thought was that since I have noticed a few things carried over from the late flatty to the early OHV, maybe the pumps are similar enough in design to adapt the piggyback pump thing to the flatty.

 

This is getting interesting, as I said, I've never heard of a piggy-backed oil pump with the extra section being used for the oil filter. But, all my Cad engine experience has been with the 54/55 and later motors and they could have used something like that on the earlier motors...

Here's a reference to the in-the-pan mounted vacuum pump, paragraph 16, page 10-16 of the 1954 Cadillac shop manual (I'd scan it but don't have a hosting program to post it);

c. Installation
1. Install vacuum line to vacuum pump.
2. Replace hexagonal drive shaft in vacuum pump.
3. Replace idler gear in oil pump and install vacuum pump below oil pump with six screws.
4. Connect vacuum line to engine block.
5. Install oil pan baffle.
6. Install oil pan.

This years manual also shows "something" weird looking attached to the bottom of the oil pump in the longitudinal cross section of the engine.

The '55 shop manual doesn't go into any detail about the oil pump, but lists all the specs. for the vacuum pump; vane and rotor to cover plate clearances and etc.

 

The more you think you know the early Cadillac engines, the more you find that you dont know! They are addictive.

 

Since block take off points have been discussed here a few pic's from one of my blocks of all the take off pionts I could find if any body has got the art computer skills to add say numbers/letters with a line and an arrow head to the points so maybe we could see what numberletter relates to what use.

 

Bump!!!

 

Like this?

 

Err...
What happened there?
Lets try this

 

Nice work CadDaddy, I see you have also identified a couple of the points which is great.
From what I know
No 1 is Oil return from the remote filter.
No 2 & 4 are on opposite sides of the block at front but no idea what for!
No 3 is the Oil take off point to the remote filter
No 4 as No 2 above any info will help
No 5 point at the rear of the block just below the head, also be interested to know what those other 2 points are next to No 5 and similar on opposite side on block?
No 6 ?
No 7 is interesting as it runs upto the valley covers and looks to be an oil feed to the center cam area but have not pulled it apart to see for sure.

1st pic and last in the numbered set you can see what actually is 2 pairs of threaded studs with nuts attached that are in the block 1 pair under the water pump down low to the right of No 4 in the last pic and directly below No 2 in the 1st pic, does anybody know wht they were used for or what attached to them???

Any info would be of great help to all cadillac flathead addicts.

 

Just because I am a bit numb... I needed to print this out to better understand what I am looking at, if anyone needs to do the same, here you go.