Oil Cooler?

[Sarris]

It's not just HD, its all MC mfgrs as well as EPA standards. Just think how good your GZ would run with an open air cleaner, open pipes, and a re-jetted carb. Same thing with HD. They just market the package better. You can drive an HD just fine without paying the Harley Tax. Its just that they run a herd better afterwards.

HD is NOT a shoddy product, this one I have is 10,000% better than the 78 Sportster I had, just a little old school. Mine has been very reliable, and I've had super dealer service (expensive). Ride one, you'll never go back.

Hell, I spent almost $4k on Baron's stuff and hi-po shit on my (gone) Yamaha 1700 Roadstar. Kinda turdy before, but ran like a raped sheep afterwards.

There is a reason God made the circumference of your ankles smaller than the grip of your palms. You always have a place to hang on.............

[mrlmd1]

Originally Posted by alanmcorcoran

Sarris,



I'm not an American-made hater (I have a Suburban and I like it okay, ten years in an no serious problems, except the @#$-in! radio died) .

The radio in my '92 Suburban crapped out too about 4 years ago. The stupid thing is in three separate electronic components, one hidden deep underneath the dashboard and almost ridiculously hard to get to and you can't find a replacement anywhere except maybe from a junkyard. Other than that, it's a great vehicle for hauling or towing stuff or going on a long trip. Like a HD except more reliable.

[Sarris]

Hey Alan, after a doing a bit more reading, and speaking to some HD owners, I have found that you are right in the fact that 07 and later HD's are having serious overheating problems. HD tried to solve the problem in the 09 model run with the rear cylinder shutdown deal, but I understand that it doesn't work and the owners are furious. 2007 was the first year for the Twin Cam 96 / 6 speed with all the O2 sensors, catalytic converters, full digital fuel injection, blah, blah, etc. The heat issue REALLY reared it's ugly head with the addition of the catalytic converters for 2007.

Luckily, mine is the first year 2006 StreetGlide with the tried and true TC 88 and nice quiet 5 speed. It is fuel injected but does not have O2 sensors or catalytic converters. It also has a 5 gallon gas tank instead of the ping-pong table sized 6 gallon models installed on the 2007's and up. I have installed the K&N full flow air billet filter, Vance & Hines true duals, and a Screamin' Beagle (sic) ignition module. My bike runs great and never overheats, but my buddy's 2007 model SG runs obviously hotter.

It is my undertanding that all motorcycles will be equipped with catalytic converters beginning with 2010 models. That's also probably the reason we are seeing all bikes going to fuel injection as they can't meet the emission standards otherwise. I'm also fairly sure that 2009 will be the last year for the (carburated) GZ.

As the architecture business is non-existant in my area, I'll not be buying a new bike anytime soon. My HD is 30 months old with just over 32k miles. I gonna keep her for some time. I guess if I ever buy another one, I'll make damn sure the overheating problem is solved. That is if HD survives the great economic upheaval.

Also, here is my new avatar with my bike at Fontana Dam, NC near the Dragon's tail.

[alanmcorcoran]

Yeah, some of the forums and threads I read got pretty, well... heated.

The Strat was often held out as an example of how a big bore air cooled could be done properly. (It's still pretty darn hot though - I can't imagine riding something purported to be MUCH hotter...)

Glad you got yours when the getting was good - it'll be worth a lot some day.

[CMS]

Originally Posted by Joho

Guys... the GZ is air-cooled for a reason... that reason being that the engine is small enough to not need any of these farkles!

If you're wanting to make sure your oil is at the right temperature, then keep your engine in tip top condition! (Spark plug for correct firing, clean oil filter to remove blockages, and high quality oil!!)

/////////// But I'am still at a loss as to why they have oil coolers on the same engine in different sales markets, ex the DR 200.
The Suzuki Van Van [a TU250 style bike] ava in England ,is standard with a 125cc engine, you can order the 200cc version, and it comes with an oil cooler. In my mind the smaller engines, including the GZ250,should have a oil cooler due to the small quanitiy of oil they operate with. I've seen oil cooler kits ava in the Japanese acc books ,but unsure if and how we coud obtain them. CMS

[Quimrider]

I would speculate that similar engines that do have the oil cooling do so for specific reasons. Even small changes in an engine can greatly affect operating temperatures that may make an oil cooler necessary or not. Maybe the DR200 intended to be operated off road may not air cool enuff with an engine caked in dried mud. The oil cooler on the Chinese 350 bike "XI" or "Tank" whoever makes it appears to empty into the valve cover. Possibly the added 100cc displacement would overheat the cylinder head if it didn't receive a constant cool oil bath from the oil cooler.

I am a mechanical engineer. Money is the biggest factor when designing something. If you can't sell it at a price people are willing to pay and make a profit, it matters not how you design it. From my engineering experience you have to look at what the design goals would have been for the GZ250. The engine was already a tried and tested design long before the GZ250 came into existence. Suzuki would have plenty of knowledge as to how the engine stands up to heat and what it's weaknesses are. Typically things are engineered to be "good enuff." With frequent oil changes and proper maintenance the engine may last an acceptable amount of time. Adding an oil cooler may increase the longevity and reliability of the engine but at an additional cost. Seeing as how the GZ250 is aimed as a starter bike. Unless it was absolutely necessary, it would not have made good business sense to spend the extra money making the bike more expensive and lowering profit and possibly losing customers to other bikes such as the Honda Rebel. Of course all this speculation is just a bunch of hot air without specific knowledge of the engineering data for the engine or doing a great deal of testing. It's entirely possible that an oil cooler may be bad for this engine.

My whole reason for even thinking about an oil cooler was that I overheated and warped my cylinder head likely due to too much time wide open throttle on the freeway. I began to try to see if it was possible or even feasible to find a way to better cool the engine. Below are the questions - answers - conclusions that I have arrived at so far.

Is it possible to add an oil cooler to the GZ250? Yes.

Will an oil cooler make any significant difference in engine temps (esp the cyl. head)? Unknown. I speculate it wouldn't significantly affect cyl. head temps as the only oil that gets up there is for the cam.

From my knowledge of air cooled gasoline engines, cylinder head temps less than 350F and oil temp less than 240F are what I consider safe. I don't know what Suzuki's temperature limits are for this specific engine so I may be wrong. If anyone has Suzuki's specs please pass them my way (call me stoopid if these are in the service manual and I have overlooked them). This summer I will monitor my cylinder head temps and oil temps. If they mostly remain under 350F and 240F respectively, I see no need to add an oil cooler. If they do however, I'll try a temporary oil cooler and if it positively affects the temperatures, I'll implement a permanent oil cooler.

[Easy Rider]

Originally Posted by CMS

In my mind the smaller engines, including the GZ250,should have a oil cooler due to the small quanitiy of oil they operate with.

If the engine has a sufficient amount of surface area on the fins on the upper engine (cylinders), the heat never GETS to the oil.

The engine on the DR200 is obviously not exactly the same as the GZ250.......and the anticipated use is not the same either. :cool:

[mr. softie]

Originally Posted by Quimrider

My whole reason for even thinking about an oil cooler was that I overheated and warped my cylinder head likely due to too much time wide open throttle on the freeway. I began to try to see if it was possible or even feasible to find a way to better cool the engine.

Maybe a dumb idea but what about trying to duct some additional air over the cylinder cooling fins.
Perhaps as the overheating problem seemed to be most severe at WOT a bit more air would be in order. A scoop/lower fairing maybe. Hmmm :popcorn:

[Easy Rider]

Originally Posted by mr. softie

Perhaps as the overheating problem seemed to be most severe at WOT a bit more air would be in order.

One more comment and then I will have said enough on this topic (maybe too much):

We know the head was warped. How do we know that overheating caused this?

IIRC, he said he has a 16T front sprocket. If that is true, I just can't see overheating in 5th gear........unless there is something else to the story. Now if one were to spend a LOT of time at WOT in 4th, then different story maybe.

[adrianinflorida]

Originally Posted by mr. softie

Maybe a dumb idea but what about trying to duct some additional air over the cylinder cooling fins.
Perhaps as the overheating problem seemed to be most severe at WOT a bit more air would be in order. A scoop/lower fairing maybe. Hmmm :popcorn:

The open flow that the fins get now should be sufficient at speed, if anything, you might cause them to get hotter when stopped or cruising slowly if you do too much shrouding.