cooling the 400ex motor

[keepitpinned]

in time im going to be getting a big bore kit for my 400. i want this thing to be cool. Im going to be getting a bigger oil cooler and a larger oil tank. I was thinking about getting the air scoops, but dont like the way they really look. Do they help that much that i should buy them. IM thinking that a larger oil cooler and oil tank will do. any help will help. :D

I have the 440 kit. As of now, I havn't done anything for the extra heat. In fact, I havn't even noticed any extra heat! I think all this talk about extra heat is exaggerated. If I decide to do something to cool my engine, it will be the oil cooler from FST.

[keepitpinned]

where do you ride? I heard that since the 400 is air cooled its power fads as it gets hotter? i heard it fads more when they get a big bore? you especailly see it when on dunes

[UglyMotha™]

the faster you go, the cooler the motor runs http://www.exriders.com/vbb/images/icons/icon14.gif

[nhs333x2]

Four Stroke tech makes an oil cooler that cools the engine by 35 to 40%.

[keepitpinned]

im already getting a bigger oil cooler and tank. i dont like the looks of the air scoops so if i dont need them i dont want them. would the bigger oil cooler and tank be enough to cool a big bore?

[promisc]

Look at this thread http://www.exriders.com/vbb/showthread.php?s=&threadid=103981&perpage=15&highlight=cooling&pagenumber=1

[keepitpinned]

i was thinking about putting some computers fans on mine, but im weird. if it doesnt really belong on their i dont want to do it. if that makes sense:blah:

[Quadzilla]

Multilple ways to cool them. I use a FST Style (not actually from FST) oil cooler to bypass the internal oil passage to the head and go thru a cooler that dumps the cooled oil into the head. I also have scoops. Who cares what they look like, they are functional!!!

There are also a couple of other options (albiet pricy):

1. Desert Toys large capacity oil cooler. Replaces your stocker and holds more oil (twice as much if I recall correctly. It's big bucks ($300??).

2. XR's only will take your current cylinder head and increase the size and length of the fins.

I've heard that the larger oil tank does not do much for cooling (can somebody confirm?). I think an FST type cooler would be your best bet. Costs less than a big oil tank and supposed to work better...

[keepitpinned]

i got money to burn so im going to drop it on a larger oil cooler and probable just get the larger oil tank. might get the scoops? do they help alot? also what kind of gas u runnin on ur 400ex Quadzilla?

[F-16Guy]

Originally posted by keepitpinned
i got money to burn so im going to drop it on a larger oil cooler and probable just get the larger oil tank. might get the scoops? do they help alot? also what kind of gas u runnin on ur 400ex Quadzilla?
More money doesn't always mean better product. A larger cooler in the stock location is going to have limited benefits because once the oil leaves the cooler, it is then routed through the filter housing, and then through a passage drilled into the side of the cylinder (which is probably the hottest part of the engine) before it eventually reaches the cam and rockers. This pretty much negates the cooling process. The FST type system picks up the oil directly after the filter housing, runs it through the cooler, and then dumps it directly into the cam and rockers, avoiding the significant heating that occurs as the oil flows up the cylinder passage. The FST cooler can also be located so that it is more exposed to the airstream, providing even better cooling. The only drawback (if you can call it that) with the FST system is that you do have to do some minor drilling and tapping to block the original passage and provide new inlet/outlet fittings for the cooler. The best part is, you still have the stock cooler working also. As for scoops; it seems to me that they could only help with getting more air over the cylinder.

[Quadzilla]

Originally posted by keepitpinned
i got money to burn so im going to drop it on a larger oil cooler and probable just get the larger oil tank. might get the scoops? do they help alot? also what kind of gas u runnin on ur 400ex Quadzilla?

Right now running 50/50 mix of premium and 110 race (@ $5 a gallon where I live). I have not tried straight premium yet, but I'm going to. My issue is that I ordered custom Cometic gaskets from C&D that are a little thinner than even stock XR gaskets by 8 thousands each on the head and base gasket. That probably puts my compression around 11.2:1 or so. Even though I can get Sunoco 94 Ultra here, does not mean that it will run well on it. When I do a local, short ride, I'll see how she runs on pump. I'm going to PA for two days of non-stop riding Thrus and Fri and am going to do the 50/50 mix to be safe (we are MANY miles away from anything at times).

[Quadzilla]

Originally posted by F-16Guy
More money doesn't always mean better product. A larger cooler in the stock location is going to have limited benefits because once the oil leaves the cooler, it is then routed through the filter housing, and then through a passage drilled into the side of the cylinder (which is probably the hottest part of the engine) before it eventually reaches the cam and rockers. This pretty much negates the cooling process. The FST type system picks up the oil directly after the filter housing, runs it through the cooler, and then dumps it directly into the cam and rockers, avoiding the significant heating that occurs as the oil flows up the cylinder passage. The FST cooler can also be located so that it is more exposed to the airstream, providing even better cooling. The only drawback (if you can call it that) with the FST system is that you do have to do some minor drilling and tapping to block the original passage and provide new inlet/outlet fittings for the cooler. The best part is, you still have the stock cooler working also. As for scoops; it seems to me that they could only help with getting more air over the cylinder.

Well said F-16! Getting scoops and an FST type cooler almost certainly does a better job of cooling than a Desert Toys cooler and large oil tank. The head needs cool oil more than anything else in the motor. It by far is the hottest and dissipates most of the heat of the motor....

[keepitpinned]

Quadzilla and F-16Guy i understand what you guys are saying, but i dont really want to drill any holes anywhere. im just scared ill f sumthin up. thats why i dont really want to take that chance. is their anywhere you think that would do it. so their liable for the work

[Quadzilla]

Just about any machine shop could do this without any issues. Any motorcycle shop with an in-house machine shop could do it also (usually not dealers, but places that built dirt or street race bikes).

[keepitpinned]

you guys help alot. where could i find a fst or fst type cooler?

[Quadzilla]

FST (Four Stroke Tech). Others here have bought them for cheaper elsewhere. I got mine from a guy who was making kits out of his basement (Jason Birklind or something like that). I think they are about half of what FST wants for them if you know where to get them. Just not sure if they come with ALL of the parts you need (including something to block off the internal oil passageway). Do a search on the forum for oil cooler.

[Quadzilla]

Oil Cooler Discussion (http://www.exriders.com/vbb/showthread.php?s=&threadid=61793&perpage=15&pagenumber=2)

[keepitpinned]

lol..i started to look at it then saw it was like 13 pages and said nm

Wow! I read that entire post about the oil coolers. They finally decided that the secret feature that made them work so well was turbulators. At one point Micky Dunlap and some other guy were even going to have a shootout between their coolers! Mickey said he never received the cooler from the other guy and the thread was closed soon thereafter. A good point was made about half way through the thread though. A stacked oil cooler is more efficient than the turbulator type. That is why all the major manufacturers put the stacked type on their machines. Dezert Toyz makes a stacked type that is 3 times larger than stock and mounts right on the stock mounts. I ride in Calif. and so far I havn't had any heat problems with my 440, but just to be on the safe side, I might just try out the Dezert Toyz cooler.;)

[keepitpinned]

golfman400ex how long have you had the 440? you dont notice a fade in power?

[keepitpinned]

how long golfman400ex?

I have only had it a few months. I don't notice any fade in power at all though. The guy I ride with has a Preditor 500 so if I experience any fade in power I am going to notice it right away. It is hard enough to keep up with that beast as it is.:D