[gromorado]

So the setup I am going to end up with is the Yuminashi 160cc Big Bore kit, Yoishimura RS-9 full exhaust, and Chimera air intake. Will an Oil cooler be necessary or even help out at all? I do a lot of mountain canyon and high altitude riding. There was another thread on here about Oil coolers but no one ever really answered the question about a non-stock Grom. I know that with a stock set-up it is not really necessary.

 

[NorCalGrom]

An oil cooler will lower your oil temp. Cooler temp = longer engine life. If I was doing the mods you are, I would spend the extra bucks and run the oil cooler.

 

[wondermuscle]

I put an oil temp sensor on my 170cc kit and have only seen a max oil temp if 207F in 70F ambient temps. Ill see what type of temps I get as the weather heats up. I don't expect to need an oil cooler, but it won't hurt...

 

[Grom'n-BR]

I put an oil temp sensor on my 170cc kit and have only seen a max oil temp if 207F in 70F ambient temps. Ill see what type of temps I get as the weather heats up. I don't expect to need an oil cooler, but it won't hurt...

Yea I think I'm gonna need one. We get 100+ in the summer here

 

[BAD ASS TA WS6]

I think it will be a necessity for some people depending on their mods/how and where they ride. Increased capacity is a plus. If your 170 kit runs around 200 @ 70 ambient I'd say that's pretty good. Definitely curious on it as summer comes full swing. I'll bet someone whos stuck in slow moving traffic or doing parking lot stunts, etc. these temps will climb pretty quick with the bigger bore setups and not much air across it.

 

[mecevans]

Cooler does not mean better.

Optimally you want the oil temps at 180°F.

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[Grom'n-BR]

How much of a pain in the ass is it to run oil coolers on these bikes and what brand are y'all using

 

[push bike]

If I learned anything from the aircooled VW guys I would be more concerned with cylinder head temps but for the sake of discussion where would you hook up your cooler? Here's the flow diagram showing the split right after the oil pump (click to enlarge):

 

[muertopvb]

Where are you getting the Yuminashi kit?

 

[Brian S]

Guys,
Mobil makes our oil at the Kohler Engines, and we have had many discussions with them. Oil has to run over 212 degrees, just to boil out the water that condenses in it. Oil in 2 strokes likes to run at 180, because 2 strokes make more power there. The optimum temperature range is 230 to 270 degree's F, for mineral based oils in an air cooled engine. Synthetics can be run up to 350F, without issue, if the engine is designed for synthetic oil. The Honda Grom 125 runs cold @ 195F to 207F @ 65F/75F. Oil temps are almost a direct linear relationship, add 20 degree's air temp, add 20 degree's oil temp. I have a digital temp gauge on my sump, on the 170cc / mod head/ induction Grom. We are finally getting into the high 70's here. I'll do some testing this week, and report back.
Brian

 

[Snakeibf]

Brian's right I'm seeing similar Temps here I think 190F is the hottest the engine has reached. I don't think an oil cooler is necessary or wanted unless you live somewhere where it is 120F in the summer. In that case you might want to check your Temps before deciding.

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[BAD ASS TA WS6]

Good news. Awesome that you guys have already gotten that far and have data to share. Keep us posted as it gets warmer. Ideally I'd rather not run a cooler but time will tell once the 181 goes in

 

[gromorado]

Where are you getting the Yuminashi kit?

From Yuminashi direct sales.

Yuminashi Cylinder Kits MSX125/GROM125

 

[Maxacceleration]

A thermostat (or by-pass) in an oil cooler system is important.
I would imagine the aftermarket oil coolers do not have that.
On a cold day, with no thermostat, oil will still flow to the oil cooler and can have the oil kept below optimum running temps. It should have a by-pass for those conditions.
In hot weather, the flow out of the motor to ambient exterior temps, will help cool the oil.
I bet Brian S.'s testing will tell a lot...

 

[Snakeibf]

A thermostat (or by-pass) in an oil cooler system is important.
I would imagine the aftermarket oil coolers do not have that.
On a cold day, with no thermostat, oil will still flow to the oil cooler and can have the oil kept below optimum running temps. It should have a by-pass for those conditions.
In hot weather, the flow out of the motor to ambient exterior temps, will help cool the oil.
I bet Brian S.'s testing will tell a lot...

Good point, something like this would probably work well.

http://www.summitracing.com/int/parts/der-13011/overview/



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[iamchris]

Brian's right I'm seeing similar Temps here I think 190F is the hottest the engine has reached. I don't think an oil cooler is necessary or wanted unless you live somewhere where it is 120F in the summer. In that case you might want to check your Temps before deciding.

Sent from my XT890 using HondaGrom.net mobile app

And who is going to want to ride in those temperatures? Sounds like an oil cooler provides zero benefit in all practical applications.

 

[RACER X]

I ride during the summer here, temp in the high 90s low 100s add in traffic and what not, I can see 120+

 

[Grom'n-BR]

I ride during the summer here, temp in the high 90s low 100s add in traffic and what not, I can see 120+

X2 on this. I'm next door in similar temps as well as exaggerated humidity

 

[Maxacceleration]

Good point, something like this would probably work well.

http://www.summitracing.com/int/parts/der-13011/overview/

Yup something like that. Plumbing the oil lines gets busy when that is added in.
I have had to pass on the thermostat before (on a project bike) as it can be hard to pinch down the lines for that 'H' fitting, location-wise, where two braided lines becomes four and the additional fittings.
There is no doubt I would have an oil cooler on a 143+ cc Grom that I would rip through the gears and get caught in traffic regularly.
But thats just me.

 

[Brian S]

Guys,
I rode the SRD 170cc, ported head, ram induction, Crower cam Grom today with a oil sump thermocouple hooked up. It was 73F ambient. I rode for about 45 minutes, trying to find every hill in the area. I never got over 197F. If I added 30F to the ambient temp, 103F, that means the oil would be 227F. I really can't see where an oil cooler is needed. I could get all the way to 260F/270F with high quality 20/40 motorcycle oil, and not have a problem.
Brian S