oil coolers

[SLO]

I was talking with a friend of mine who worked with Runt Pittman when he was with Morgan McClure racing. It seems that this guy was so smart that he figured the only place you need oil is where it is used,which is not in the crankcase.The oil in the crankcase is opposing the power of the combustion. Light bulb comes on in my head? The most noticeable improvement would be on this type application, My 143cc Honda Trail. So, MC, what thoughts do you have on this idea of adding an oil cooler with a higher capacity oil pump,and how would you calculate the volumetric amount of oil? Or would you bypass the crankcase mainly , or keep the amount in the system to all but remove the oil in the crankcase. This is why adding to much oil is not good,as well as other reasons!

 

[m in sc]

i run a high volume pump on mine, and i also increased the oil restrictor port from 1.2? mm to 2.0mm but i think you are referring to going dry-sump? as far as volume, figure out what the pump capacity is at max rpm, add 20% and there's your volume per min, hour, whatever, then figure out the gpm thru the smallest port its going to be pushed though. me? i don't care personally on this motor as its nowhere near stressed, ever. . why did i fit the HV oil pump? because i was in there doing the manual clutch conversion. w the higher volume pump, the oil restrictor could then be opened up. this way, on cold days, the oil pump doesnt have to work as hard to get oil up to the top of the motor quickly. (or on cold startup)

IMHO, an oil cooler never hurts unless you are in really cold environment, neither does added capacity. IMHO, the only good way to add a cooler on the CT125 is to use a cylinder with the added oil ports in it which interrupts the oil going up to the head, though the cooler, then continuing up to the cyl head. the 'bleed off' styles that feed off the head bolt, to me are kind of a joke.

in my opinion, the ct motor doesn't need an oil cooler end def doesn't need to be dry-sump.

 

[RideMyMonkey]

IMHO, an oil cooler never hurts unless you are in really cold environment, neither does added capacity.

If you add an aftermarket oil cooler and then need to operate in Cool Ambient Temps all you have to do is change to Engine Oil to the "Cold Weather Oil Viscosity Spec" that's noted in the Bikes Owners Manual.

Usually Cold Weather Multi-Weight Engine Oil for Bikes start at 0 weight (on the low end) and 20W-30W on the high end of the viscosity.

Not only do you have to follow the OEM oil's viscosity rating but also the API Oil Quality Grade. Just make sure to follow the Factory Oil Spec in the API Oil Spec or higher grade.

Here's the API Oil Spec broken down and explained;
API OIl Specs Explained

 

[m in sc]

good link^

i mean, 10w40 is good from -22f to 104f. reason i said cold weather is the extra cooling w the oil cooler might not let it warm up enough to cook off any condensation, not nec due to lubricity. if it were ME and i still lived in an area wher eit was cold a lot more, id run 5 w 20 in the winter.

. i'll be honest, I run 20-50 (good to ambient 122f) from spring through fall, and 10w40 in the winter.

 

[RideMyMonkey]

in my opinion, the ct motor doesn't need an oil cooler end def doesn't need to be dry-sump.

Its depends on the Operating Environment and Requirement of the Engine, (i.e. average sustained work loads).

Example; In SC you probably never experienced Ambient Temps (sustained) over 110 for a Month or more. In Arizona this high temp environment (105-118 F Average) is common in the Summer and Early Fall.

Then add in a change in Elevation from 1,300 ASL(Phoenix) to 7,600 ASL(FLagstaff) and now you have another Horse Power-Stealing/Operating Heat Generating thing called Density Altitude.

This is why the 912 Aviation Rotax Engine is Fuel Injected and Dry-Sumped. They took the Automotive version of the Rotax and kept fixing failures until they had an nearly built Proof Light Aviation Engine.

The main purpose of the Dry Sump in the Aviation Rotax is more to insure oil pressure at Non-Level Operating Attitudes such as 90/45/180 where a wet sump's oil pick up would cavitation.

In Automotive Racing Engines Dry Sumps are use to remove the oil from the reciprocating parts that would normally be oil bathed and this decreases drag on the Reciprocating Parts this increasing Horse Power Output.

Oil does more than Lubrication, it acts as a Heat Remover in an Internal Combustion Engine.

I hope this helps.

 

[m in sc]

Im well aware of how an oil cooler and and dry sump system works. However, we do have a month of about 100 degree days in the summer, or damn close to it. even 1 day matters so who cares if its for a month +. But, that doesn't make any difference.
this isn't an aviation motor, as it has a much wider range of RPM, for 1. also, the air is a LOT cooler at altitude but as said, is offset by density. you know dry sump in an airplane motor also has a lot to do with the forces that would be exerted on a wet sump system and possible starving/frothing, ie: cavitation as mentioned. apples to oranges vs the CT. 100% totally different situation.

the 1st gen CB750s were dry sump, i know, i owned plenty. the 2nd gen all the way up to the last run of aircooled CB1100's are wet sump. I know, i own one and have had all in between. Know why they weren't dry sump? not needed. same with most production race bikes. Windage can be handled by sump shape and overall motor design including baffles, etc. to deal with a wet sump system.

as said: not needed on a CT motor, no where close. I've seen these motors putting out (grom) well over 400-500% stock horsepower with a simple oil 3 row cooler and zero need or desire for a dry sump system. Have i seen dry clutch setups? yes but maybe to save what, 1-2 hp on a 40hp build?

yes, oil is a coolant. but the surface area and open nature of the CT motor also allows the whole engine help cool the motor oil. Nothing to worry about on a CT even at 120F, just run the right weight of oil if you live in that environment. But, id like to point out as long as its done right an oil cooler really cant hurt either.

 

[Salty Sway]

Im well aware of how an oil cooler and and dry sump system works. However, we do have a month of about 100 degree days in the summer, or damn close to it. even 1 day matters so who cares if its for a month +. But, that doesn't make any difference.
this isn't an aviation motor, as it has a much wider range of RPM, for 1. also, the air is a LOT cooler at altitude but as said, is offset by density. you know dry sump in an airplane motor also has a lot to do with the forces that would be exerted on a wet sump system and possible starving/frothing, ie: cavitation as mentioned. apples to oranges vs the CT. 100% totally different situation.

the 1st gen CB750s were dry sump, i know, i owned plenty. the 2nd gen all the way up to the last run of aircooled CB1100's are wet sump. I know, i own one and have had all in between. Know why they weren't dry sump? not needed. same with most production race bikes. Windage can be handled by sump shape and overall motor design including baffles, etc. to deal with a wet sump system.

as said: not needed on a CT motor, no where close. I've seen these motors putting out (grom) well over 400-500% stock horsepower with a simple oil 3 row cooler and zero need or desire for a dry sump system. Have i seen dry clutch setups? yes but maybe to save what, 1-2 hp on a 40hp build?

yes, oil is a coolant. but the surface area and open nature of the CT motor also allows the whole engine help cool the motor oil. Nothing to worry about on a CT even at 120F, just run the right weight of oil if you live in that environment. But, id like to point out as long as its done right an oil cooler really cant hurt either.

+1
Comparing airplane to CT125 - umm no
Comparing racing engine to CT125 - umm no
The design of the CT125 motor has been around for decades and is a very popular motorcycle in Thailand and other Asian countries. Temperatures hit 120F in Thailand last year along with 110+ in many other countries, will venture to say most of the CT125's and other motorcycles/scooters are abused and lack basic maintenance yet they survive. Adding a dry sump for shits and giggles ok, always fun to experiment is it needed - umm no.
There is a wealth of information from the members here and I appreciate the experience they provide.