how many have upgraded to external oil filter?

[tcrane29664]

just wondering, and any input on level of difficulty of installing it appreciated

Tim

[hanleyclifford]

The external oil filter is easy to install if you buy the Indigo kit. But you should know that the system is limited in that it only filters the "bleed off" from the oil pressure relief valve. If your engine requires the oil adjuster to be turned in anywhere near "bottoming", your actual filtered oil will be minimal. Nonetheless, the filter is a good upgrade and any A4 with a view to long term survival should have one.

[marthur]

Every thing Hanley says is true, but I will add two thoughts:

First, a new oil pressure regulator is part of the Indigo kit. The Indigo oil pressure regulator is rock steady--much more that my original atomic 4 regulator. I usually see something like 37 PSI at startup and 40 PSI at cruise.

Second, Tom Stevens claims that the Indigo system will filter all the oil in the system every few minutes. I have seen a big improvement in my oil color clarity since adding the filter. For that reason I am very happy with my installation.

I also agree with Hanley that the Indigo kit is a breeze to install. I have limited access to the carb side of my motor, but it still took only 60 to 90 minutes from start to finish (and about 20 minutes of that was spent finding something I dropped).

[Dave Neptune]

Yep

Tim, I insttalled a bypass type filter when I bought mine 27 years ago. My engine is 42 years old and is original except for #4 exhaust valve.
It was very simple to tap into the preassure sendor and return o to the reversing gear cover. It took longer to mount the filter than to do the hook up.

Dave Neptune

[Cool Beans]

Nonetheless, the filter is a good upgrade and any A4 with a view to long term survival should have one.

My engine is as far as I know, no filter original and 37 years old. . .what's long term after this point

Seriously though, I've contemplated the oil filter mod but never felt it was that beneficial without filtering the primary oil passage like in an automobile.

[hanleyclifford]

My engine is as far as I know, no filter original and 37 years old. . .what's long term after this point

Seriously though, I've contemplated the oil filter mod but never felt it was that beneficial without filtering the primary oil passage like in an automobile.

Unquestionably the benefit of installing an oil filter on the A4 filtering only that amount of oil that is bled off by the relief valve is marginal. There is, however, something to be said for running the oil, even rarely, thru a filter with the view of picking up the odd chip. The better method is an independent pump. The marginal value increases in proportion to your dependence on the engine.

[ndutton]

I'm sure it's no surprise where I'm at on this. Cool Beans said it pretty well.

Atomic 4's were produced from 1947 to 1984, most on this forum 35 or more years old and not a single one with an oil filter for most of its life (filters being a relatively new wrinkle) and now we should have one for long term survival? Anyone have a guess of the number of engines that succumbed to dirty oil as opposed to corrosion related problems?

Look, if you want a filter then by all means you should have one, I'm just not persuaded by the discussion in favor compared to 65 years of history. And counting.

[marthur]

So Tim, the answer to your question is that many of us have installed the oil filter and some have not. It is relatively easy.

From the discussion you might infer that we have questions to answer and not enough data to do resolve the debate. Does the Indigo system clean the oil well? Only an analysis of the oil from a filtered engine would answer that question adequately but some of us claim noticeably clearer oil at a 50 hour oil change.

Second question: would the cleaner oil benefit the engine by reducing issues associated with impurities, such as wear? And more importantly: is the difference enough to reduce the lifetime of the motor? This one is not likely to be settled in any definitive way because of the many variables that arise in the life of a machine that might last half a century before rebuild.

A third question is whether there is some other benefit to have oil filtration. Things I have in mind are longer intervals between oil changes, fewer sticky deposits on valves or rings, etc...

The cool thing about this forum is that we can disagree and still be supportive and friendly. How many other places can you have discussions with people who are clearly insane (as indicated by their not agreeing with you) but still genuinely like them?

[tcrane29664]

The external oil filter is easy to install if you buy the Indigo kit. But you should know that the system is limited in that it only filters the "bleed off" from the oil pressure relief valve. If your engine requires the oil adjuster to be turned in anywhere near "bottoming", your actual filtered oil will be minimal. Nonetheless, the filter is a good upgrade and any A4 with a view to long term survival should have one.

tonite when we cranked her with a guage installed for oil pres, she's gettin 40 at idle, 72 and up with more throttle...

tried my best to get the phone's video to work, could not, will post video when I go back down on Thursday.

[tcrane29664]

Every thing Hanley says is true, but I will add two thoughts:

First, a new oil pressure regulator is part of the Indigo kit. The Indigo oil pressure regulator is rock steady--much more that my original atomic 4 regulator. I usually see something like 37 PSI at startup and 40 PSI at cruise.

Second, Tom Stevens claims that the Indigo system will filter all the oil in the system every few minutes. I have seen a big improvement in my oil color clarity since adding the filter. For that reason I am very happy with my installation.

I also agree with Hanley that the Indigo kit is a breeze to install. I have limited access to the carb side of my motor, but it still took only 60 to 90 minutes from start to finish (and about 20 minutes of that was spent finding something I dropped).

thanks for the info, i'm runnin about 40 at idle, 70 and up as throttle increased. will probably be ordering the indigo, but don't think I'll wait about the install, which right now is scheduled for Fri afternoon or Sat morning...can't WAIT! lol

[tcrane29664]

So Tim, the answer to your question is that many of us have installed the oil filter and some have not. It is relatively easy.

From the discussion you might infer that we have questions to answer and not enough data to do resolve the debate. Does the Indigo system clean the oil well? Only an analysis of the oil from a filtered engine would answer that question adequately but some of us claim noticeably clearer oil at a 50 hour oil change.

Second question: would the cleaner oil benefit the engine by reducing issues associated with impurities, such as wear? And more importantly: is the difference enough to reduce the lifetime of the motor? This one is not likely to be settled in any definitive way because of the many variables that arise in the life of a machine that might last half a century before rebuild.

A third question is whether there is some other benefit to have oil filtration. Things I have in mind are longer intervals between oil changes, fewer sticky deposits on valves or rings, etc...

The cool thing about this forum is that we can disagree and still be supportive and friendly. How many other places can you have discussions with people who are clearly insane (as indicated by their not agreeing with you) but still genuinely like them?

well put, and this forum is like finding gold ...

[hanleyclifford]

tonite when we cranked her with a guage installed for oil pres, she's gettin 40 at idle, 72 and up with more throttle...

tried my best to get the phone's video to work, could not, will post video when I go back down on Thursday.

72 psi is excessive; suggest you back that out so you get 40 psi at cruise.

[marthur]

The idle oil pressure can be signicantly lower than 40 psi. 20 psi is common at idle. However I seem to recall a recommendation tha the oil pressure not exceed 60 psi. Can anyone else help with that?

[thatch]

Two Things

Higher oil pressures than the recommended 40 psi has crept into the conversation a few times lately. One thing that has not been mentioned is that, that increase in pressure is not "free". In other words it takes horsepower to create oil pressure. In recent years, in regulated classes of drag racing, "savvy" engine builders have lowered the oil pressure to about 45 psi in a quest gain back some of the horsepower they were loosing at 80 psi. Granted, these engines are only performing 1/4 mile at a time, but they are apparently having success with this approach. For years the rule of thumb has been 10 psi of oil pressure for every 1000 rpm, so, bearing this in mind, 40 psi for our A4's should be ample. Getting back to the question of adding an oil filter to these engines, I agree it can reduce wear "but" I would seriously consider adding "fresh water cooling" if it's in the budget before adding the oil filter. Why?, every season we loose more and more A4's from age related rust out. The cleanest oil in the world won't help if your block rusts through.
Tom

[marthur]

Tom, your thought about FWC makes a lot of sense. Here on the Great Lakes we can't avoid FWC, so I don't tend to think about it. That is one of the reasons I can power my dinghy with a 1957 Evinrude : )

Mike