I have recently rebuilt my 8BA and it's back in my 36 Coupe. The motor previously had the by pass canister oil filter which appeared to work OK but with a small leak through the top bolt on the canister. The system includes a line bringing oil to the filter from a plug alongside the oil pressure bender plug. Oil is returned to the pan from out of the bottom of the canister. My new engine fired up and ran well but the oil canister leaked like a waterfall. I lost over a quart by the time I noticed it was leaking. Maybe 1 minute had passed. I further tightened the bolt at the top of the canister but that didn't stop he flow which is coming from the top ring seal. Am I missing something here? I was reading of restricters that maybe need to be in the line to the canister to restrict flow but then I also read regularly about how little flow there is in these by-pass systems but by the look of my garage floor my filter certainly has strong flow. Should I persevere and try a new canister, is there a restricter of some time that I need to fit or do I forget the by-pass filter and plug the line from the block. The car doesn't do many miles and regular oil change won't be an issue but I'd like to know why I have a flood. Advice appreciated.
There is a restrictor fitting that allows just a bit of the oil coming up from the pump to be diverted into the canister and then back down in the pan. You might search over on the FordBarn for a source to get one from. In the mean time, just remove the feed line from the back of the block and put a plug in there to take the filter out of the system. I think Ford only offered the oil filter as an afterthought and marketing ploy.
Restrictor in inlet was designed to lower oil flow to less than the rate of oil exit back to the pan...typically the gaskets cannot handle unrestricted flow because when inlet is delivering more than exit deletes the whole can is under full system pressure. Flow also has to be low because this is a bypass from main system and filter itself is a finer medium than a full flow filter, filtering the oil slowly but with smaller particle removal... Remove fitting on inlet side, drill and tap for whatever bolt (or carb jet!) you have around, drill your new plug to .060 or thereabouts (closest drill you actually can find), and consider the system complete.
Thanks for replies. I gather it also didn't help that I filled the cannister to the top with oil and pumped the rest in through the oil prressure sender hole to make sure I had oil at the top of the engine on first start up with new cama nd lobes. The system would have imediately been on full pressure. Any idea why Ford didn't take advantage of the full amount of oil flow that is clearly available and increase the size of the line back into the pan?
Bruce. That restrictor fitting of .06 (1.5mm) sounds very small but it's consistent with some other commentators who are suggesting even .04. I can't see how the cannister bypass system can be of much use at all but I gather under pressure they still produce sufficient flow?
Weatherhead made a special restrictor fitting #1512 that had a .062 hole in it,it was 1/8M to 1/8 F pipe thread. Many cars up to the mid 50s had NO provision for anything other than a bypass system.
The bypass system continually filters oil that is bypassed from the bearing feed...eventually it gets everything, and since it does not have to flow full volume it has a finer filtration medium than the "full-flow" which has to take a lot of volume. According to tests, also, full flow filters spend a lot of time bypassing...they cannot handle cold oil adequately, and many cannot handle the flow of high RPM either. That's why they have bypass valves...a fully flogged SBC can have real full flow with parallel truck size filters, but of course race engines are also closely monitored and changed frequently so clogging is not a problem for running without bypass. The .060 was a ROUGH estimate from an original...I could only find slightly smaller and slightly larger drill bits, and the straddled results suggested .060 was realdamnclose. Good to have that actual catalog dimension from JE. I suspect the ultimate FH oils system for durability would be original bypass filter plus the WWII type full flow through a modern FF filter. This would give the best of both worlds, and a sound engine with good oil pump would not be troubled in the least by the oil tapped off though the bypass. I understand similar setup is used on expensive engines like huge diesels and such...all oil filtered on its way to bearings, continual partial filtering through a very fine element to remove the stuff that a full flow filter cannot handle. Add in a PCV, done.
It sounds like you do need the restrictor on the inlet side, it also sounds like there may be a couple of other things happening. Either the return is somehow blocked, I don't know why, or perhaps the restrictor has been fitted on the return side. Another thing isb that the top gasket or seal is completely shot so it will leak whatever you do. One last thing to consider - on my beehive filter the oil inlet is at the bottom and the outlet is half way up the side. I hon't know how the original ford one is plumbed, but yours at least is backwards compared to my beehive aftermarket one. If in doubt you can remove the filter and plug the hole in the bock while you sort out what is going on. I'd prefer to run a filter if I had one, but not running it due to no filter is not really necessary. Mart. Edit: I had a quick look around via google and the only illustration I could find did show the oil return coming from the bottom of the stock canister.
I have found some more pics of the stock 8BA. In the side, out the bottom. Opposite of the beehive. Mart.
Well, crap. I just ran up to the garage and popped the hood on the truck. I misspoke. Mine comes from the block up to the side, returns out the bottom.
Nope. There are at least a couple of variants, as some years put the pressure sender there on the side inlet of the filter, others just link the tube fitting to the hole in the filter can. They look about like common brake line fittings except that one branch is necked down to a tiny hole, less than 1/16". Use what you have, just drill and tap for a drilled out plug or solder it shut and drill the solder...
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