Spin on Oil Filter/Oil Cooler (SOHC)

Wolfe_11B

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Seen a few pics before on the site of the oil cooler mod, but nobody really has gotten into it deep on here. Just thought I'd show that it can be done, and what is required to do it. I've only recieved a few pieces so far, so I will update the thread as the parts come in.

First off, the spin on filter. Why switch? Well, personal preference I suppose. You have quite a bit of options (like 40) when it comes to off the shelf filters at the local stores and online. You can pick and choose between filter media, filter construction, spring style, pressure of valve, filter length, etc. With a stock filter you have a max of 5 choices. The stock filter setup works perfectly fine and when you put a decent filter in it, it works no different than a spin on filter. So once again, this mod is personal preference.

Yamaha used our XS400 filter system on many bikes for many years. Same cover, same bolt, same filter, on most of those. If you do some snooping around, you can see that Yamaha offered an adapter plate to convert the internal filter to a spin on filter. This plate simply goes against the crankcase, has a union bolt that threads in, and then you just spin the filter on. This plate will work on any Yamaha that utilized that same size filter o-ring found on our bike. If you do a parts search on our o-ring, you can see about 75 models/years listed. Here is the adapter plate and bolt, OEM Yamaha-

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I got this plate and bolt for $9 on ebay. Tons available out there.
Plate Part Number- 3TJ-13461-00-00
Bolt- 90401-20007-00, 90401-20145-00

If you are looking at ebay or a junk yard, you can try looking for 'Yamaha oil plate', 'FZR Oil Plate', 'XJ Oil Plate', etc etc

If it sounds too easy so far, well, there is a catch when it comes to our bikes. The area on our crankcase(and other motors that this can be used on) are not machined the same. Specifically on our motor, there is a raised center portion with another raised area that sits above it, before reaching the sealing area. This prevents the adapter from sitting flush against the crankcase. Not so good, unless you want the oil all over the garage in a matter of seconds. Here is a picture of the area in question-

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So there are a few options here to get this working properly.
-Machine the motor side of the plate adapter ~3mm in the corresponding questionable area
-Machine the case where the high area is to be level with the o-ring surface

Well, I did a combination of both to get mine to work. Took all of 2 minutes with my handheld Bridgeport(rotary tool). And just like that, it fits and seals-

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Now the filter I chose is not the one you would want to use if you do this mod. You would want one that is about 2.5-3 inches long, giving you more filtration area. I had to use this short filter due to my oil cooler plate, which will be covered in the next installment when the parts come in.

I'll let you cross reference filters on your own, but this list is a good starting point- http://fzronline.com/forum/viewtopic.php?f=8&t=234 The sealing area on the filter side of the plate is pretty large, giving you quite a few options. Just do your due diligence in doing some measuring and research before grabbing a filter. Thread size is M20x1.5 on the bolt.

I don't have stock pipes, so I can change the filter with my headers on, but before doing this make sure you can clear your stock pipes or aftermarket pipes.
 
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Moving onto the oil cooler. I'll update it as the parts come in.

So why use an oil cooler? You may be thinking "My bike didn't come with one, other bikes didn't come with one, and they seem to do fine for a long time". Well, that's absolutely true. You don't need one at all. Without getting into the engineering and physics of it all though, I can say that even though you don't need one, you should run one. Our motors may be listed as air-cooled, but they are in fact oil-cooled as well. The engine internals get a LOT of cooling from the oil, as well as lubrication. Let's pretend here that the oil we have is only lubricating, and that the only cooling you get is from the air. These motors would die and be junk within minutes. The XS250/360/400 setup does in fact have an oil cooler as well. It's the oil filter cover that I removed in the post above regarding spin on filters. Those fins aren't on it just to make it look cool :) So lets make the oil a lower temp, what are the benefits? Well there is a lot of that physics stuff involved, that I said I would skip. But I can assure you that cooler oil, maintained within a certain range, will be better for your motor in the long run. Why didn't Yamaha put an oil cooler on these then? It's simple economics, a cost to benefit calculation. Putting a system like that on an entry level, low price point, commuter bike would be worthless from a business standpoint.

So lets get into what we can do. There are quite a few different options here, and I can't cover them all. It really depends on your budget, your mechanical aptitude, and tools available. You need a few main pieces to get an oil cooler on the bike-

-Oil cooler 'radiator' or 'core'
-Lines for oil flow
-Adapter to tap for oil send and return, or a place on the motor to tap into

For coolers, you can grab pretty much anything you'd like, as long as you can get it to fit. Keep in mind that you need mounting points, clearance with the exhaust/tire/moving parts of steering/etc, and an area the flows air well. You can source oil coolers off of other bikes to use from ebay or junk yards. Use a cooler that will match up to the type of fittings or lines you choose(next paragraph). You can use pretty much anything you'd like as a cooler as long as it can withstand oil, and be safe for pressures up to 80psi. Just because something isn't listed as an oil 'cooler', doesn't mean it wont work. Transmission coolers, AC condensers, hydraulic coolers, the list goes on and on. Use your imagination. Some do work better than others. Stick to plate/fin or tube/fin radiators, avoid those tube 'heat-sink' style coolers made for choppers (they won't work any better than your stock filter housing). The one I grabbed is a pretty standard cooler, made in china. It's been sold in the US for a long time under different brand names but you can grab one at cost from the direct china market sites. Cost is around $30.

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Next you need to choose your lines. You can go with fittings that use push on hose with worm gear clamps, SS braided hose with banjo fittings, or go 'baller' with AN fittings and hose. It's all up to you and how you want to go about doing things. Don't go too big on hose, but at the same time don't go too small. -8 AN is a good I.D. for our oil system. -10 is more along the lines of what you'd need in a car motor. Could probably get away with -6 on a bike, but any smaller and you won't be flowing well through the cooler and the bypass might kick in. You can use plain rubber hose rated for high pressure oil, but SS braided has it's benefits, mostly being it's durability. You can get SS hose with nylon over it, if you don't like the color. I decided on generic AN fittings and hoses from china (Same stuff sold at 'performance shops' here in the US). Don't spend big bucks on fittings, they are not 'true' AN anyway, unless you get them from an aircraft supplier.

And now for the fun part, how to get the oil to the cooler. Just like with the adapter plate for the spin on filter, Yamaha also made an oil cooler plate with fittings that works on the same set of bikes. This adapter can be found in junkyards, breakers, and ebay as well, sometimes for dirt cheap. It simply fits between the motor and oil filter housing. You can even toss the spin on adapter over it, eliminating your filter housing (you won't need to do all that grinding if you go this route). The Yamaha part works by constantly flowing oil from the motor, into and out the cooler, then routes it into the filter and back into the motor. The adapter has a bypass valve on it which opens directly into the filter if the lines or cooler become clogged for any reason. There is a downside to this adapter- the line outlets interfere with our cranckcases. From what I have seen, some folks manufacture a piece that goes between the motor and adapter to space it out so the lines can clear. I've also seen some modifications that tap off one fitting and machine another, so they are right next to each other, then you can run the lines up or down instead of off to the sides. It's some work, but it can be done. I haven't dived into the one I have here, since I just don't want to deal with it. But it is an option. Drewpy Might have some input, I know he has some info on the adapter on his blog.

Yamaha part number-5N1-13461-01-00, 4K0-13461-01-00

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You can also do your own taping of oil passages ways to get oil into and out of a cooler. I'm not going to get into it, as it is beyond the scope of what most people can do. In order to do it properly, you would need to tap into the case at an oil passage before it splits to the pathways, run into the cooler, and then tap back in. Would require blocking between the out/in point on the case. Let's just move on :)

Another way is to buy an aftermarket 'sandwich' cooler adapter. There are a few floating around out there from back in the day that are the same size as the Yamaha one from above with better routing of the lines that may bolt right on and be usable. Some quick ebay/google searching yields many results. As always, do your research before buying!

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And now my method. If you use the spin on adapter from the previous post, you have opened up endless options for oil cooler adapters. There are hundreds of different ones you can find that are sized for modern applications. Check ebay, aliexpress, Dreale, Mocal, Mishimoto, Summit, Jegs, etc. These adapters will give you options of fitting sizes for the inlet outlet, taps for oil pressure or temp gauges, etc. Just make sure to get one with the proper size adapter bolt, will most likely be M20x1.5 if you haven't gone astray from the original setup.

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I chose an adapter with a special feature, that I would recommend for anyone doing this mod. It has a built in thermostatic valve that only allows oil to flow to the cooler after reaching a certain threshold. This allows for faster warm ups and keeps the oil and engine in a stable operating temperature range, much like a water cooled system. I think this Mocal unit cost me $13. Might switch to a Mishimoto version, simply since they were designed and made here in the US. But this one will do for now.

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That's all there is to it. You need to be the deciding factor on how to implement all of this. Plan out all your parts before ordering, make sure everything will work. Don't waste your money, doesn't grow on trees anymore :) I'll add a few pics of my setup with line routing, cooler placement, etc after all the parts get here so you have a reference of one way to do it.

You can go crazy as well, I'm adding a fan rack behind my cooler with a tiny thermostat that wedges into the cooler fins. Will keep the cooler working when stopped and idling. I'm building a second motor as well strictly for my landspeed events to keep me in the 400 class, and it will have a separate oil cooling system with jets that direct oil constantly onto the piston undersides, as well as a spray bar in the head under the valve cover. I can't get into that more unfortunately, since 'loose lips sink ships' in the racing world. Will be a real oil cooled motor at that point, similar to Suzuki's 'SACS'.
 
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<snip>
I got this plate and bolt for $9 on ebay. Tons available out there.
Plate Part Number- 3TJ-13461-00-00
Bolt- 90401-20007-00, 90401-20145-00
<snip>
If you are looking at ebay or a junk yard, you can try looking for 'Yamaha oil plate', 'FZR Oil Plate', 'XJ Oil Plate', etc etc Took all of 2 minutes with my handheld Bridgeport(rotary tool). And just like that, it fits and seals-

Very interesting on the adapter plate, I've used things like that many times on large diesel engines, never knew till today that one was available for this application. Ones I found on Ebay were a little more, $16 with shipping, still not bad! It been ordered!

Love the term "Hand held Bridgeport"! I've used it's cousin the "Redneck metal lathe" for small items, chuck the part in the 3/8 drill and have at it with a file!
 
Very interesting on the adapter plate, I've used things like that many times on large diesel engines, never knew till today that one was available for this application. Ones I found on Ebay were a little more, $16 with shipping, still not bad! It been ordered!

Love the term "Hand held Bridgeport"! I've used it's cousin the "Redneck metal lathe" for small items, chuck the part in the 3/8 drill and have at it with a file!

You need to discover the 'best offer' feature on ebay, the one I grabbed was listed for $16 as well :thumbsup:

I've used the redneck metal lathe as well, many times!
 
This would be great for a racing app. But like you said the stock setup works just fine also. If they didn't we would not see xs400s' with 50k+ miles on them. :)
 
You need to discover the 'best offer' feature on ebay, the one I grabbed was listed for $16 as well :thumbsup:

I've used the redneck metal lathe as well, many times!

I'm not sure if that was an option on this item, but yes that feature has saved me a few bucks in the past. But for $16.95 including free shipping thought it was a good deal. Some I saw did not have the "bolt" in the picture so I passed over them.
 
I was wondering if it'd be possible to forgo the adapter plate by drilling and tapping the crankcase itself in order to screw a hose fitting directly into the feed from the oil pump, then fabricate a threaded reducer for the return line.
It'd mean relocating the oil filter but it'd greatly reduce how much the adapter and filter protrude in front of the motor.
 
Yes you can, right at the bottom port. Looks like enough meat there to tap for an NPT thread. Then just use a relocation plate, and return into the standard return location with a M20x1.5 fitting with a proper sealing washer against the case. Not something I'd do on my only crankcase, but if you can find one to test on I'm sure it would work.
 
This is great info! Love the idea of a spin on filter, as you say, so many more choices for filters. I noticed the extra brackets on the frame and assume they must be for mounting the oil cooler, though there are no pictures of it installed.(Maybe still a work in progress)
I have been thinking of trying to make, or modify an existing crash plate to protect the filter and the underside of the case.
 
Engine mounts are different on the 81-82 sohc xs400. They removed the upper rear engine mounts and added rubber bushings to the lower rear ones to help reduce vibes. Also the stock mufflers have rubber bushings to the frame. It does make for a smoother ride compared to the earlier bikes, but I have seen a few with broken rear frame tabs with this setup. I have also found handling to be not as good with the 81-82 sohc bikes with this setup. The motor will "twist" or move more in the frame under on/off throttle actions. This causes the bike to feel loose while riding. I prefer the older style solid mounted motors. :shrug:
 
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I almost forgot to update. I have my cooler on, with the adapter plate/thermostat. I had to take the temporary mounts off for welding, but you get the idea of where it will be. No leaks from the cheap AN fittings, quite happy about that. The way I'm mounting it will allow for quick removal for oil filter access. I'll get a pic of that when it's all done. Was going to mount it higher up, but with the front lowered for land speed, the tire comes way too close for my liking. Where it sits now is a better spot, I've seen a few Suzukis and Ducati's with the cooler in the same location. Some might be worried about road debris, but I can find absolutely no documented cases of broken oil cooler from tossed up road crud. Will it get beat up? Probably. Will it get a hole? Probably not.

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I just cranked it with ignition off for about 6 seconds until I saw the oil pressure light go out. Ran the bike for 2 minutes to give the cooler time to fill and purge air through the system(it has a small bypass in the housing to always allow oil to flow to the cooler even with thermostat closed). Gave the outlet line on the cooler a small crack, and it's sure full of oil :)
 
nice adapter plate, probably better than the original type.

couldn't see a link to it though, have you the specs so I can find one?
 
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