Increasing Engine Oil Capacity - grayracer513?

14 replies to this topic
  • MarshalGiles

Posted October 17, 2008 - 07:19 PM


I did a search, but didn't really find what I was looking for, so here goes:

I have a DS'd '05 WR450 and plan to do some long trips with it in the future (1000+ miles). Trips that long kind of pose a problem, because it seems the consensus is that oil should be changed every 500-700 miles at the latest with this type of riding. In the interest of stretching those intervals a bit, I'd like to increase the oil capacity of the bike.

I read a post by Grayracer a while back mentioning that you could safely run 1.5 liters of oil (1.2L is specified) in a steel framed WR with no problems and I intend to test that theory. However, I'd like to see if i can increase it a bit more than that if possible via adding an auxilliary oil tank. I'd be extremely happy if I was able to get 2.0L of oil capacity in the bike.

Have any of you experimented with adding an auxilliary oil tank to your WR? I've seen some posts where Indy added an oil cooler to his bike, but it doesn't really add that much oil (6 oz if I remember right).

Am I right in assuming that if I can increase the oil capacity, then I can increase my oil-change intervals as well? Can anyone see problems with increasing the oil capacity that much?

Thanks in advance

EDIT: I'm talking about adding an auxilliary oil tank to the system, not just dumping 2 liters of oil in at the next oil change. I didn't make myself very clear in my description, evidently.

  • grayracer513

Posted October 17, 2008 - 08:00 PM


You will not enjoy an attempt to run 2 liters of oil in an '05. That amount will exceed the physical capacity of the tank, and the return oil will force the excess back to the top end of the engine via the pressure balance tube. The sump level will be higher than it's supposed to be, and you'll end up with a smokey, oily mess on your hands.

  • MarshalGiles

Posted October 18, 2008 - 05:05 AM


Hmmmmm.... I re-read my post and I didn't make myself very clear on what I intend to do. I was talking about adding an additional oil tank in the system, hopefully with the capacity of .5 liters or so to boost the capacity of the stock system. I was thinking that if I could run 1.5L with the stock setup, then adding an auxilliary .5L oil tank would bring me to my arbitrary capacity of 2.0L.

Am I right in thinking that there is a direct relationship between oil capacity and time between oil changes?

  • tweav

Posted October 18, 2008 - 05:56 AM


One of these days I'll get around to putting my oil tank on my 07 . but for now It's just a little more trouble then I feel like dealing with.I have modify the side on my motor just to get a oil pressure line .

It's a totally differant story on your bike . all you have to do is keep your tank very low like make it out of a skid plate the make a tank so that the pressure line hooks to the bottom or lower on the tank and hook the return line right on the top that way it will not siphon back into the motor .

I did make my tank But I have to mod my case to feed it oil . I may do that on this winter's taer down .

here's mine in the early stages of welding it.

Posted Image

  • MarshalGiles

Posted October 18, 2008 - 06:16 AM


thanks Tweave. I did stare at my bike for about an hour last night trying to think of a way to put a tank behind the skid plate. While it may be possible, i figured it was a bit more trouble than I wanted to go through, plus, it didn't look like I could really fit more than 200-300 ccs in there. I'm looking for a bit more than that. To really use the space efficiently, the tank would have to be a really complex shape.

I'm considering making a 500cc tank to put right in front of the base of the cylinder or possibly just behind the right radiator. One behind the radiator might be too high, however. Maybe some of the experts here could tell me if that's true or not. I'll keep looking into this. Thanks for your input.

  • tweav

Posted October 18, 2008 - 08:20 AM


I don't really think it would matter at all where you would mount the tank or how big it is as long as you would put a check valve in the supply line .

  • grayracer513

Posted October 18, 2008 - 08:21 AM


It should be made so that the level in both tanks is the same, if at all possible (talking about steel framed bikes here). Route the return line to top of the new tank, then run a line from the bottom of it to the frame reservoir, and a balancing vent from top to top.

Adding more oil will extend your OCI time, but not on a strictly linear basis, necessarily (doubling the oil won't double the OCI).

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  • mikeythefokker

Posted October 19, 2008 - 11:39 PM


I think that Rekluse makes a clutch cover that holds a few more cc's of oil.

  • grayracer513

Posted October 20, 2008 - 06:14 AM


Since the YZF is a dry sump, expanding the clutch cover will add nothing to the oil capacity of the system. The return pump draws oil down below that level in operation, so it's just extra air space, and clearance for the Rekluse pressure plate.

  • BIGMatt

Posted October 20, 2008 - 07:41 AM


I can safely run with 1.5 liters in my 04' WR450.
If there is too much oil, it will just flow out the cam-cover breather hose.
If you want to add any more capacity, then you'll have go with the external tank/oil cooler route or a giant clutch cover.

  • grayracer513

Posted October 20, 2008 - 07:55 AM


If you want to add any more capacity, then you'll have go with ... a giant clutch cover.

See my post just above yours.

  • MarshalGiles

Posted October 20, 2008 - 10:03 AM


Ok, how bout this?
What would be a good volume to shoot for? Should I be satisfied with the 1.5L I can get without building anything? I plan to do long trips on this bike.

I did some investigation this weekend and found that I can fit an additional .5L behind the left radiator with my 6.6 gal tank on (that really limits where I can put stuff). It's going to take a ton of work, however, so I'm wondering if 1.5L should be fine.

  • Lennie

Posted October 20, 2008 - 11:55 PM


Why dont you just cut the frame and make the "tank" area bigger?

  • grayracer513

Posted October 21, 2008 - 06:08 AM


Why dont you just cut the frame and make the "tank" area bigger?

That is really not as impractical as some might immediately think, but you do want to be sure the engine can be removed when you're done. Adding to the bottom of the down tube, expanding into the area between the cradle tubes would be the best approach.

  • 123BigcoopDawg576

Posted October 21, 2008 - 06:15 AM


this is probably going to be your best option.

http://www.thumperta...ight=oil cooler

FYI you can do long rides on this will just need to change the oil about every 300 miles. also make sure you gear the bike for the long straight aways. i had over 11k miles on my wr before i sold it and it was rock solid never had an issue.


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