Bloo

What else can you do? Well, a lot actually. If there are other marks on your flywheel, like to set valves or something, as long as you know their degree positions, you can duplicate them. The same goes for ignition base timing marks. You could also make TDC marks for all the cylinders. Those, along with a dialback timing light would allow you to see things only guys with distributor machines normally see, like timing errors in the points cam. I have a distributor machine, and already know my points cam is mostly rubbish, but it's easy to do now so why not? On a four stroke engine, as used in almost all cars two rotations are needed to fire all cylinders. On most of them this implies that you only need half as many TDC marks as you have cylinders. For instance a typical inline four cylinder fires every 180 degrees of crank rotation. That means that you only need one more mark, halfway around the balancer or flywheel. The common type of American V8 with the cylinders arranged in a 90 degree vee fires every 90 degrees of crank rotation. In that case you need to make a mark halfway around the balancer or flywheel just like the four cylinder, and then make marks 1/4 of the way around. A typical inline six like our Pontiac guinea pig here fires every 120 degrees of crank rotation. That means we must divide the balancer or flywheel by thirds. This Pontiac balancer is a 6 inch balancer almost exactly. Actually 5.984" if I remember correctly. Let's divide it into thirds. Convert that to metric: 5.98x25.4=151.89mm Convert diameter to circumference: 151.89x3.14=476.93 Divide by 3 for first mark at 1/3 the circumferencce: 476.93/3=158.98 Multiply by 2 for the second mark at 2/3 the circumference : 158.98x2=317.95 Round those to the nearest whole number and we have marks at 159mm and 318mm from TDC. I made a zero mark and marks at 159mm and 318mm on a piece of paper. Then I wrapped it around the balancer with 0 aligned to TDC. Made a mark at 159mm: And one at 318mm: Then I aligned the 318mm mark to TDC, and wound the paper around the opposite direction to check my work. And 159mm aligns to a mark: So does 0: Looks good. It matches in both directions around the balancer, so there are no errors. I marked them with blue paint to differentiate them from "real" TDC which is marked in red. What else can we do? How about the factory ignition timing marks? A flathead Pontiac has two of them on the flywheel, 2 degrees and 6 degrees. The circumference is 476.93mm, so: Find how many mm per degree: 476.93/360=1.32mm Multiply by 2 for 2 degree mark: 1.32x2=2.64mm Multiply by 6 for 6 degree mark: 1.32x6=7.92mm Round and we have 2.5mm and 8mm. I marked these on a piece of paper and transferred them to the balancer: I marked them with white paint. Now what? How about timing tape? With timing tape, you can suss out distributor curves with a plain timing light, one with no dialback. I already had some MSD timing tape here. They give you a bunch of different sizes for different size balancers. Fortunately, 6" was one of those sizes. Not for showcars I guess, but pretty handy on anything else. I also put the purple dots back in case the tape falls off.

Enter the giant Zip Tie. I am not the guy who came up with this, and I don't know who did. I have seen it posted various places on the Internet. It doesn't necessarily have to be this big. In fact this one is almost too big. I had to file on it a little to get it through a 14mm spark plug hole. The tail of the zip tie needs to be really long though, so you can't possibly lose it in the engine. Here is how it is done: The zip tie head follows the piston up at the far side of the cylinder. It gets caught between the piston and the head and stops the crank. I did the same thing once before to the car in the picture above, but it wasn't all disassembled then. Access was terrible. I made a pointer from welding rod to bolt on at the generator slider bolt. It had an offset so it would locate itself against the timing cover in the same place every time, but had to sort of stick up to miss the pulley. Not ideal. As I recall these marks were made with drops of paint on the end of a kebab skewer, due to the terrible access. 30 and 40 had already washed off when the picture was taken, and are edited back in. That white block over to the left is reflective tape for a Harbor Freight photo-tachometer that never worked. TDC is really the only mark you need if you can use a dialback timing light, but that is a shaky proposition on this car. This time around the pointer will be more solid. It is a pointer from a 1949-1954 Pontiac, and after being spaced out 3/8" further than it was on the newer engine, it fits. Next, the battery gets disconnected if it wasn't already, and all the spark plugs get pulled out. We don't want any uncontrolled movement of the crank. The zip tie gets put in, and is arranged so it's head is dragging the cylinder on the far side as previously discussed. The engine is turned over gently by hand, with a wrench. The zip tie is guided up the cylinder wall by the piston until it stops. The first temporary mark is made. I'm using pencil here because it is easy to get rid of. These temporary marks will have no meaning once TDC is found. It doesn't matter which direction you go first. Apparently I started with the counterclockwise direction in these pictures. Now carefully crank it around the other way, guiding the zip tie up to the same spot as before. It's clockwise this time in these pictures. Make a second temporary mark. Note the first temporary mark. TDC is exactly between these 2 marks. If you are working at the end of a kebab skewer, you might have to get really creative. With things wide open like you see here there are lots of options. One might be a fabric measuring tape. The only thing that makes it the least bit difficult is that the surface is curved. I wrapped a piece of paper around the curve and transferred the 2 marks. 62mm. We will be working in millimeters here because the metric side of this ruler has finer graduations. Half of that is 31mm in this case, so I make a mark. And then took it back to the balancer and transferred the mark. Made sure it was square to the pointer.... And then painted it red. The temporary marks can be erased now. If you can use a dialback timing light on your particular car, TDC is all you need. I'll be making some more useful timing marks anyway. Stay tuned.

The lack of a "true" Top Dead Center timing mark is a problem that has come up in several threads recently. This thread aims to show how to get a TDC mark on a completely assembled flathead engine that is still in the car. A true TDC mark is essential when troubleshooting tough driveability problems. Nobody thinks about it until they need it. In fact, I have seen many people building engines without checking it, thinking "I'll just time it with a vacuum gauge" or whatever. That might be fine until the car starts misbehaving, and maybe the cam has jumped time, or the distributor advance has screwed up in some way. There is no excuse for not checking the mark and correcting if necessary while the engine is out and apart. When the engine is not out and apart, and does not at least have the head off, it is a bit more work. The principles here apply to all piston engines, not just flatheads, and there are plenty of reasons you might not have a TDC mark. Maybe you have one of those Buicks that can have the flywheel bolted on one right way or five wrong ways, and the last guy put it on one of the five wrong ways, and you don't want to take the rear axle, torque tube and transmission out of the car to fix it. Maybe you have an engine where some dreaded previous owner mixed parts from different years resulting in no usable marks. Maybe the marks are on the flywheel, inside a hole, and you would like some marks up front you can see with a timing light, preferably without a bunch of parallax error. I fall into that last category. Some common methods of finding TDC on overhead valve engines include attachments with micrometers, dial indicators, etc. The other day someone suggested filling the cylinder with oil, and watching for the oil to rise in a clear tube. All of these things work, but tend to be difficult and slightly ambiguous because the piston is moving so slowly at TDC. Quite a bit of crank movement occurs without much piston movement. For this reason, I prefer the "piston stop" method. If the piston is not at top dead center, it is moving a lot more compared to the crankshaft. What is the piston stop method? A pointer is added to the engine if necessary. Some sort of a stop is put in place and the crank is rotated until the piston hits the stop. Then, a temporary mark is made. Then the crank is rotated the other way until the piston hits the stop again. Another temporary mark is made. A permanent third mark is made exactly halfway between the two marks. This third mark is true TDC. Is this perfect? No. It can be slightly wrong due to offset piston pins or cylinder bores. Long ago when I was in college, and could still remember how, I calculated this error for some common American V8, probably a Chrysler one. The error was less than 1/3 of one degree. I consider it negligible. When engines are apart, usually something like this is used. Actually the ones I have seen professional engine builders using were even simpler, usually a piece of steel with a nut welded or brazed on the bottom for a stop. This guy made his fancy and adjustable. Of course you could get really fancy and buy a commercially made anodized aluminum one like this: But that doesn't help if the head is on. On overhead valve engines you can usually screw something in the spark plug hole. My tool is a spark plug base with short 14mm threads, a piece of steel rod brazed in, and the tip ground approximately hemispherical. It works in more engines than you would expect. There are a million different kinds, and most of the professionally made ones are adjustable length like this: Of course you should be really familiar with the which way the valves move in the engine you are working on. You wouldn't want this thing getting tangled up in the valves. I have seen tools that have a very small diameter protrusion. The downside is the small diameter protrusion would get bent easily. None of this helps us on a Flathead engine though, as hardly any of them have the spark plug hole over the piston. It is almost always somewhere over the valves. But there is a way. More to come....

Any pounding that those shims in combination with the bearing take is pounding the new kingpin bushings do not have to take. Kingpins and bushings even when done right never seem to last long enough. If it were me I would want those shims bomb proof.

I looked into getting some of that. The green stripe hose is tough to find in 1-1/2", and it is expensive. Wow. I found a chunk of similar NAPA wrapped hose on Ebay. According to the parts book, the original was a piece of bulk hose cut to 7-1/4". Someone suggested wiping the modern marks off with acetone. that didn't work on this hose, still I don't think it is going to show much when installed. More goodies from @Kornkurt :

Well if you don't want to do that, you could drain some of the coolant out of the car, heat it up to 200F, and beat the snot out of it with an eggbeater as shown in this thread: https://forums.aaca.org/topic/375509-bloos-not-quite-scientific-antifreeze-foaming-test/ . You'll have to forgive me for not knowing what Type B coolant additive is. That is not a term I have heard used up in my neck of the woods. Whatever your coolant is, that test done on a sample drained from your car should sort out whether the foaming is the coolant's fault. I wouldn't be scared of soluble oil. I know some people think it impedes heat transfer. Through the 1960s or so, "rust inhibitor and water pump lubricant" that was really just soluble oil was used with water in the summertime around here because heat transfer was thought to be better than with ethylene glycol. I was still doing this on a couple of cars in the 80s. I never heard anyone even postulate that it might be screwing up cooling efficiency until the 2010s, despite widespread use in the old days. Your mileage may vary. But first, I would check the car with a "block tester", a sort of pump thing that uses a blue liquid to check for CO2 in the air above the coolant. Get the coolant hot but not boiling, and suck some of the air in the top of the radiator through the tester. It should not turn yellow. I know you looked for cracks. Sometimes they don't show. PTFE is the generic name for Teflon, and it didn't even exist when these water pumps were made. It is highly unlikely that they could need it to work properly. Packing type pumps need to leak a little or the shaft will burn. The rub is that if it leaks too much, the shaft will suck air and foam up the coolant. It should be wet if you put your finger under the packing nut. P.S. I would not shy away from any flow test @edinmass suggests just because the radiator is new. There have been multiple cases posted in this forum where a radiator was new but the wrong sort of core material was used resulting in insufficient flow and overheating.

Niagara Falls?!! Slowly I turn.....

NEVER use teflon tape anywhere near a carburetor. It finds it's way into the float valve and causes fires. The float valve (and inlet fitting) accept a double flared bundyflex steel line. It is the same thing as a 5/16" steel brake line used on American cars before the change to metric. The flare does the sealing, not the threads. Brass fittings exist that imitate a steel double flare and could connect to that, but what you have doesn't look like one to me. It looks like pipe thread, and if it is, there is no way that is going to work. The red gasket must seal on it's own. If it won't, you probably need another one. Look as the surfaces the gasket contacts on the carb body and float valve for possible damage. Always hold the float valve with a wrench when you tighten the gas line to it, otherwise you will have leaks.

There was at one time a rubber dam at the top of the radiator. It is a big no-no to let air get from the front of the car to the engine compartment without going through the radiator, if you care about cooling at all. If air can go around, it equalizes the pressure on the back of the radiator with the front, so far less air flows through the radiator. Some cars do a better job of this than others. Some are so over-engineered it doesn't matter, but I think those are in the minority. This car clearly had a dam at the top. Unfortunately there was only about a 1.5" x 2" piece of it still there. I bought 1/8" neoprene sheet on Ebay, and started making patterns from paper. It was not a symmetrical hole and not obvious. Pretty soon I had a pattern but a new problem. A while ago in this thread I soldered the mounting brackets back to the radiator where they had broken loose. What I didn't notice at the time was that the bracket that holds the rubber air dam was broken loose at one end. It was in a horrible spot, too. It was not only right next to the core, a Harrison strip core that might fall apart if you get it too hot, but it was also right where the top tank solders to the side tank on this oddball cross-flow radiator. I protected the core as much as I could with a piece of copper like I did earlier in the thread. I got it soldered but heard a "pop". Fearing the worst I painted the area with lacquer, turned the radiator upside down. I poured Acetone in there, the idea being that if there was a leak the acetone would come through the hole, wash off the lacquer, and make it obvious. It took 3 tries but I finally got it soldered with the bracket attached and no leaks. WHEW! Here is what the rubber air dam looks like: As unlikely as it seems, that actually fits right. One more thing to do, get some better timing marks. The timing marks on a stock 1936 Pontiac are on the flywheel, and very hard to see with a timing light. Pontiac did not put the timing marks on the front until 1949. It looks like this. I believe this pic is one of @cevensky's engines. My 36 has never worked with any timing lights except one super-simple one running on a 12 volt battery. It has never worked with any tach, in fact the electrical system is so dirty it seems to interfere with and sometimes break digital electronics. Several years ago I added a timing mark to the front. It was a simple piece of bent welding rod, and I made marks to go with it. When the car is all assembled, the access is terrible. You can't really get your hand down there at all. It looked like this when I took the car apart. It was arranged with an offset from the bolt so that as you tightened the bolt it would bump against the timing cover and always land in the same spot. It had to stick up a little like that to miss the pulley. Functional, but far from perfect. With all this wondeful access I decided to either find one of those 1949-1954 pointers like the one on cevensky's engine, or remodel this one with another rod down from another bolt pushing down, an idea copied from the Pontiac pointer. Obviously the Pontiac one is more solid. I didn't know if it would fit, but there was at least a possibility because the 49-54 engines that used it take the same timing cover gasket my engine takes. On my trip east to the Flathead Reunion this year, I was on a mission to find one of those pointers. On the way back I caught up with @VW4X4 at a farm close to Pittsburgh. He has a bunch of engines that have been outside but have some good parts. There were 2 Pontiac flathead sixes out there, an Olds straight eight, some Mopar flathead sixes, an early Olds Rocket 88 v8, a flathead Mercury v8, and probably some others I have forgotten. Check out his "Field of Engine Dreams" thread: https://forums.aaca.org/topic/369768-field-of-engine-dreams-pgh-pa/ I got this from @VW4X4. It was a little rusty, but I cleaned it up and filled the pits with brass. Looks nice now... But does it fit? No, and the reason is a surprise. I was imagining that those later engines probably had a larger diameter harmonic balancer, and that this would probably bolt on but be a mile away from the balancer. Nope. The balancer is the same size. This pointer doesn't stick out far enough, and it hits the pulley. The cure was easy. Putting the pointer up on top of the generator slider and spacer, instead of below it moves the pointer out 3/8". I added a 3/8" spacer at the other end and a longer bolt. You can see the new spacer at the right. It fits perfectly this way. At this point I tumbled to the probable reason the balancer sticks out further. This car uses a really wide fan belt. I don't know if they were still using those in 49, but probably not. Now it is going to need some timing marks on the balancer. I might make a separate thread about that since the subject seems to be coming up fairly often lately. More to come....

That was a common emission control in the 1970s. A charcoal canister is usually used. I think some systems existed that did not have a canister, but if so that did not last long at all. I don't recall why but there may have been some explosions. If you do this, you want a charcoal canister. The plan goes something like this: The vent hose from the gas tank goes to the canister, and as the gas expands and the vapors come out, they go through a bed of activated charcoal where they are trapped. Any air is expelled through a grille in the bottom of the canister. When the car is cold, and the coolant is cold, a coolant-temperature-vacuum-switch in the coolant sends a vacuum signal to a purge control valve. Sometimes the purge control valve is mounted right on the canister. This purge control valve connects engine vacuum to a larger hose known as a "purge hose". Using the purge hose, engine vacuum sucks air backwards through the charcoal canister, sending any stored vapors back to the engine to be burned. You don't really get any good out of the fuel. It just happens when the engine is cold and running on choke. It won't mind some extra fuel.

I mentioned earlier that it is impossible to get the radiator out with the radiator shell still on the car, despite what the manual says. I suspect that maybe it is possible on a 1935 and the changes were never noted. Maybe. Two important changes occurred between 1935 and 1936 that could have affected that. First, the 1936 hood extends forward over the radiator area. Underneath that, the radiator neck projects up through a hole. You can see the radiator neck and cap sticking through the hole in this internet photo of a 1936 Deluxe Eight. The other thing is that the headlights are bolted to the side of the radiator shell. The rear headlamp bracket stud goes through the radiator brackets. The radiator brackets are clearanced in the front-rear direction, but not in the up-down direction. Sooner or later, those headlight brackets have to come off. When replacing a water tube on a 1936, there is just no way you are going to remove the radiator and the silver streak (or grillle) and just pull the tube out the front of the car like you can on many other years of Pontiac. There are 2 possible avenues. One is to remove the whole nose as an assembly, and that is probably the less work, especially on reassembly. The other is to remove the radiator shell from the car, leaving the fenders still mounted. Of note here is the fact that if you are going to take the radiator out too, there is no advantage I can see to taking the whole nose off. You will still have to remove the shell from the nose to get the radiator out. To come out, the radiator has to come up to disengage itself from the two bolts at the bottom. That is assuming you can even get them loose, because the straight-slot heads are completely blocked. It would then have to go down to clear the neck where it goes through the hole in the picture above. The harmonic balancer would need to be removed and out of the way. It is blocked by the headlight brackets. When you remove those, you find out that it is also blocked by the support structure for the fenders. All of that is a waste of time. It doesn't move near enough, and it doesn't come apart. You don't need to take the radiator out to do a water tube. You can either take the nose off, or take the radiator and shell assembly off to get clearance for the water tube. The radiator and shell assembly, once unbolted, slides straight up toward the sky to come out. If you are taking the radiator out also, you might as well just take the radiator shell off of the car, take the shell to the bench, and disassemble it. The headlight brackets had a gasket underneath originally. Not much to work with here. A pattern emerges. A scan of this pattern next to a ruler exists. I'll edit it in later if I can find it. I wanted to add redundant grounds for the headlights while this was all apart. One reason I never did it was that the wires should probably run between the radiator and the grill and I didn't particularly want them whipping around in the breeze and banging. With the shell off and the radiator out, now is the time. How do you keep it from blowing around? Solid wire! My dad used wire like this to ground electrical panels decades ago. The tabs are made of brass sheet. If I were doing this again, I would use copper for the tabs and the little tubes to solder wire to at the ends. I already had the brass here so I used it. Silver soldering this was really tough. I was expecting some trouble because the wire was so much heavier than the brackets and tubes, but due to the extreme heat-sinking of the copper it wasn't just tough, but about impossible to get the wire hot enough without melting the brass. Not recommended. If the tabs and tubes were copper, it would still be a little tough due to the disparity in thickness but not so bad. Also if everything was copper it could probably be soldered with phos-copper instead of silver, which is cheaper by a lot. Anyhow it worked. Then I soft-soldered some wire to the tubes at the ends and painted it all black. The wires at the right end of the pic were left long because I didn't know how long they would need to be. The ends with the ring terminals go to the headlight brackets. Ideally these would go all the way to the bulb sockets, but getting there without drilling unwanted holes is a problem. This isn't perfect, but it is pretty good. At the other end, the first piece of metal these encounter when they pass into the engine compartment is the front engine mounting plate, and that is what they will attach to. On a 36 Pontiac, that plate doubles as the generator mount. There is no better location, as the generator is where the current comes from when you are going down the road.

I wouldn't ruin a backing plate over that. Will a nut splitter fit in there? That is your best bet, followed by a cutting torch. In the interest of not damaging the wheel, I think I would try to fit some copper sheeting in around there to avoid overheating the wheel too much with the torch. It also might be possible to use a cutoff wheel to cut a "screwdriver slot" into the whole mess, nut and stud, stopping just short of the wheel to avoid damaging it. Then try to break up the nut with a chisel.

Sweden may be a bad example. Most if not all Swedish cars had the steering wheel on the left before the 1967 change. There were a lot of left hand drive American cars in Sweden at that time as well. A Swedish friend told me it was utter chaos on the day the change was made.

Oh no, its completely real. Just like this:

That might be some kind of a record for worst pictures.

I hate to be a wet blanket here, but this is not a time filler for 6 months, this is a time filler for the rest of your life. If 6 months seems reasonable for paint on the Chrysler based on what you have been told in the beginning, I would plan for more like a year and a half. That is about how complete body and paint jobs go if nothing goes wrong. A year and a half is still not enough time to consider this car as a time filler. Of the two projects, Cadillac and Chrysler, this Cadillac is the big one, and by a large margin. When theses cars were contemporary, they needed a lot of tinkering. It was more of a normal thing at that time. Average cars from the mid 70s spent a lot of time in the shop. Cadillacs, being loaded with extra parts and features that could potentially misbehave, needed quite a bit more tinkering than the average car. Now it's over 40 years old. If this particular year and model of Cadillac is not something that you have been wanting for yourself for years, you should run away screaming and hope it doesn't catch up.

Well, mats for just about everything are out of stock just about everywhere. I've not seen any Ford mats unpunched, so you would have a bunch of holes in the wrong place. Also, the floor contour is completely different. AD Chevy trucks are way too wide, Most Chevrolet repros for the 1930s, when they existed, had at least one Chevy bowtie on them, and most had a whole bunch of Chevy bowties. Buick Repros have a Fisher Body emblem on them. This, I think, is a 36 Buick 40 series repro in a 36 Pontiac. This is probably the closest thing that existed by far. I couldn't get one. All out of stock both in brown and black. Bob's has been contemplating a run for a while. I am no longer holding my breath. It is worth an ask in case it happened recently. 1935-1936 Pontiacs, 1935-1936 Oldsmobiles, and 1936 Buick 40 series are all almost the same body, so the size and outer shape should be close enough. Unfortunately the floor contours and pedal positions and other holes vary quite a bit. Case in point, as you know the 1936 Pontiac has a bit of a transmission hump, while the 36 Buick 40 has much less of one. The 1936 Buick 40 has a floor that is almost completely flat. In particular, look at how far to the right the gas pedal mount is. It would be way up on the transmission hump in a Pontiac. It's a miracle that brown mat fits as good as it does since it's made for a floor with almost no hump. Looks nice though, doesn't it? Here is my 36 Pontiac with a cut down unpunched 1937 Buick Roadmaster mat. The transmission hump on the 37 Roadmaster mat is just right... at the front. It fits perfect there. But, the Pontiac hump tapers down to nothing and the 37 Buick stays the same. You might have to add a little padding. I did. There are also some bumps at the back you can see sticking up that are for a 37 Buick floor contour I don't have. It's not a big deal. It's all under the front seat where it isn't hugging the floor. There is one spot on the toeboards, just to the right of the top of the gas pedal in the picture, where another little piece of carpet pad would make a more perfect fit. You have to cut off a lot. It loses the entire outer border and edge bead. I believe these are the same mats as the Buick 40 mat for 1937, just unpunched. The new wood-less bodies for Pontiac, Olds and Buick 40 for 1937 are wider than our cars, more like the large series Buicks from 1936. In any event centering is super critical because of where the cut lands. In many of these repros, the transmission hole is not quite where it should be. No word on whether Buick's original mats had this problem. Don't assume the marked spot for the shifter is right. It isn't. Measure and remeasure before cutting. One other thing. Pontiac dimmer switches are in a different spot. This is true even when comparing 1937 Pontiac to 1937 Buick 40. The hole needs to be punched in a spot where it appears not to belong.

Me too. I've been looking about 6 years. So far, only this. My skepticism is off the charts. I recommend taking a really, really close look at this before you start making a mold or something.

I've got a factory photo I'll dig up soon. I am extremely skeptical of it for a lot of reasons. I wish an original would turn up somewhere but to the best of my knowledge it hasn't.

Me too. Generally the closest ones are Buick (more on that when I find my notes), although in recent times everybody seems to be out of stock of every mat. The Ford ones don't look close to me.

Short answer: No and no. Part numbers for 1936, from a 1937 parts book: 2dr with bucket seats - 4071292 All four door - 4067370 2dr without bucket seats, all coupes - 4067295 Universal mat, cut to fit any style - 601635 Wild speculation: The first 3 are almost certainly brown, the last number was probably really meant to service much older cars that did not have a part number listed. Probably black. Probably not intended for 1936. I'll probably have more to post about this as soon as I can find my notes.

Would it be possible to get a little tube over the end of 31 from the outside? It would probably be better to blast backwards with brake or carb cleaner if you can figure out how. If you cant, maybe soak it in carb cleaner (dunk it) for a couple days and try to blow the nozzle out with compressed air. If you removed the power valve and introduced compressed air in that hole (with a rubber tip), would that pressurize the nozzle? it looks like it would from the diagram.

That is exactly right. Full flow oil filters don't really take the bad stuff out. You change oil to get the bad stuff out. Full flow filters are not intended to catch the smallest particles. If they did, they would plug in a very short period of time. It is more important that some oil get through. Full flow oil filters will bypass when they are plugged and when the oil is cold, but then they aren't filtering at all. Their main purpose it to keep large trash out that would embed in the bearings and shorten their life. Over time this has proved to be a good idea for engine life, but it is far from perfect. If you want to remove the tiniest trash from oil, a partial flow filter is the way to do it. Since they cannot stop the oil supply to the engine, extremely tight filter media can be used to trap extremely tiny particles. I don't have the statistics handy, but all the oil in the engine goes through the filter in a shorter time than you would think. They really do help clean up the oil, as opposed to a full flow whose main job is to keep larger particles from becoming embedded in the bearings. Partial flow filters are no panacea though either. I doubt they remove all the acid for instance. Probably not all the water either. My guess would be they catch mostly soot and worn metal. They aren't used on any modern cars that I am aware of. Changing the oil is still what really matters.

What happens if you put carb clean in a main discharge tube from the venturi end? Where does it come out? EDIT: Never mind. I just found some EE drawings. Apparently it leaks the extra power valve fuel out of the accelerator pump nozzle, with no connection to the main circuit. If it isn't blowing fuel backwards through the check valve when you pump, where *is* it going? It must be going somewhere, or it would just block you, hydraulically lock, and not let you move the piston. There might be a way to put compressed air on the nozzle. In one of these drawings, there is a plug straight up into the bottom of the casting that leads to the passage of interest. If the plug is there, you would have to have the check valve in place (preferably with a drop of oil), and the power valve in place, and the plunger in place, which would have to be held in VERY solidly. You could put air in that plug and have it blow out the nozzle..... I think.

What happens if you blow carb cleaner into a main discharge tube with the power valve removed? Does it show up down below where the power valve is supposed to be?