Bypass oil filter

I was just looking at the oiling system for the Model A engine.
It looks to me like there should be a metering hole in the true "bypass" system to ensure a sufficient supply of oil to the oil galley since this system taps into the oil path that feeds the oil galley. I suspect the resistance of the oil filter itself may provide enough restriction to the bypass flow to ensure this.
On the other hand the "partial flow" system returns the oil to the oil galley thus eliminating any concern that the oil filter system would starve the oil galley of its proper volume of oil.
Interesting trade off.
 
I don'r know if you guys follow Adrian's Astra-Werke youtube channel, but he has a video you may be interested in. Its about installing the bypass oil filter. You can skip the first 4 minutes where he tried unsuccesfully to make his own oil filter system. He tests the bypass filter kit's flow and at the end comments on how much cleaner his oil looks at the 1500 mile point.

https://youtu.be/PkyNgPPTziU
 
GeneBob said:
I was just looking at the oiling system for the Model A engine.
It looks to me like there should be a metering hole in the true "bypass" system to ensure a sufficient supply of oil to the oil galley since this system taps into the oil path that feeds the oil galley. I suspect the resistance of the oil filter itself may provide enough restriction to the bypass flow to ensure this.
On the other hand the "partial flow" system returns the oil to the oil galley thus eliminating any concern that the oil filter system would starve the oil galley of its proper volume of oil.
Interesting trade off.
Click to expand...

This is an often-discussed aspect when designing DIY bypass systems: what is the size of the restrictor port that you put in front of the filter so that it doesn't divert too much oil? I have not considered this an issue with the Snyder's/Kenz bypass kit because, well, there's a lot of smart folks who worked on that kit and I just assume they thought that part through. The brass elbow that installs at the block has a 3/16" restrictor on it. For pressurized systems, 1/16" is a size you see a lot.

Interestingly, Amsoil sells a bypass system for modern cars that goes the other way – they have you install a restrictor in front of the full-flow filter. The effect of this is to increase the back-pressure at the oil pump, which (according to them) is supposed to cause the computer to run the pump harder, which then increases the flow going through the bypass without decreasing the flow going through the stock full-flow filter. I guess the tradeoff is wear on your oil pump. Just an odd piece of trivia I came across.
 
Well, I guess the oil filter is not enough restriction then.
I saw the video, it is fun to see what people try when left to their own inventiveness.
 
alexiskai said:
This is an often-discussed aspect when designing DIY bypass systems: what is the size of the restrictor port that you put in front of the filter so that it doesn't divert too much oil? I have not considered this an issue with the Snyder's/Kenz bypass kit because, well, there's a lot of smart folks who worked on that kit and I just assume they thought that part through. The brass elbow that installs at the block has a 3/16" restrictor on it. For pressurized systems, 1/16" is a size you see a lot.

Interestingly, Amsoil sells a bypass system for modern cars that goes the other way – they have you install a restrictor in front of the full-flow filter. The effect of this is to increase the back-pressure at the oil pump, which (according to them) is supposed to cause the computer to run the pump harder, which then increases the flow going through the bypass without decreasing the flow going through the stock full-flow filter. I guess the tradeoff is wear on your oil pump. Just an odd piece of trivia I came across.
Click to expand...

Can you furnish the link for us? I would like to read this.

John
 
johnneilson said:
Can you furnish the link for us? I would like to read this.

John
Click to expand...

OK, hmm, I was remembering it slightly wrong. This was the BMK-13 dual remote setup. There is a restrictor placed in front of the FF filter, which increases the upstream pressure, which causes more oil to flow through the bypass, which is upstream of the FF. I couldn't find any official Amsoil lit about it, but here's a discussion on a tribology forum.
https://bobistheoilguy.com/forums/threads/amsoil-bmk-11-vs-amsoil-bmk-13.48297/
 
alexiskai said:
OK, hmm, I was remembering it slightly wrong. This was the BMK-13 dual remote setup. There is a restrictor placed in front of the FF filter, which increases the upstream pressure, which causes more oil to flow through the bypass, which is upstream of the FF. I couldn't find any official Amsoil lit about it, but here's a discussion on a tribology forum.
https://bobistheoilguy.com/forums/threads/amsoil-bmk-11-vs-amsoil-bmk-13.48297/
Click to expand...

hhmmm,
OK, it is not computer controlled, it is referring to a multi filter element system where one filter returns oil to the engine in a non pressurized area.


John
 
I found I still have a remote oil filter mount that has been bouncing around in my tool box for 40 years. I am tempted to put together a set up like Katy shows in post #3.
 
GeneBob said:
I found I still have a remote oil filter mount that has been bouncing around in my tool box for 40 years. I am tempted to put together a set up like Katy shows in post #3.
Click to expand...

I've also seen bypass setups that modify one of the inspection cover bolts to accept a small return line from the filter. The returned oil goes through the bolt and dumps into the timing gear area. Sorta like a Snyder's kit by other means. The advantages would be (a) greater flow because gravity isn't working against you and (b) easier to remove, no need to buy a fresh valve cover.
 
Alesiskai,
That sounds intriguing. Do you have a source or know where I could find some pictures?
Thanks,
Gene
 
GeneBob said:
Alexiskai,
That sounds intriguing. Do you have a source or know where I could find some pictures?
Thanks,
Gene
Click to expand...

Took me six weeks but I tracked down a picture for you. This is an ad from The Restorer, Jan 1971. This particular one does modify the valve cover, but you can imagine one that doesn't.
 

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And for good measure, here is the first ad for the full-flow valve cover kit, from The Restorer, May 1986. A classified ad for this appeared the previous year, Mar. 1985, that read in part, "I can’t keep a secret! Now there is a full flow oil filter for Model A’s. A quality product that works. Filters all oil before it is circulated thru engine, $119.95. First introduced at 1985 MARC business meeting."
 

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Re: Bypass oil

No matter what you do, if the oil being pumped up the oil shaft past the spring that holds the pump, spacer and distributor spacer in the cam valley increases oil pressure that is higher than the tension of the spring let’s the oil out into the valve chamber. That bypasses the entire oil filter setup, think of the spring that the oil pump shaft goes thru as a pressure relief that’s cracks open when ever oil pressure exceeds spring strength. I think Ford would design every part of the oil system as “fail to the safe mode” with the distributor/oil pump spring and spacer being off seated if oil pressure exceeds spring pressure. I bet the after market tube that goes into the oil passage to the oil filter produces enough back pressure to allow oil to escape before it even gets to the filter and dumps into the valve chamber all the time. The oil you find in the filter is probably a small amount that shots into the filter setup that pulsates in with the pulsating relief of pressure of the oil spring. Don’t get me wrong, if I could insure oil in my coupe is filtered I would be first line to do it. Would be interesting to put a pressure gauge at the intake of the filter and one at the outlet to see I if there is flow. Bet most oil is bypassed into the valve chamber due to pressure over riding the spring. Look at the design next time valve cover is off, you can displace the oil spring/spacer with your finger. I still have the filter valve cover filter set up I will sell cheap, cash only.
 
Hi everyone,


If I have understood all of this correctly:

The delivery volume of the oil pump through the filter is very easy to see if the end of the return pipe is made through a short piece of transparent hose at the bottom.
 

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Years ago I worked on some 3406 "Cat" engines that used both a full flow and a bypass oil filter. Anyone ever tried this on a Model A?
 
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