Oil cooler install

[Megadan]

Originally Posted by OneLeggedRider

Well.. I wouldn't fault anybody for putting an oil cooler on, it's probably a good idea. That being said, these little motors were designed to handle that heat. From the research I've found Honda designed the CG engine without an overhead cam because the people using them didn't change the oil and might even be using vegetable oil or worse for lubrication. I started out on air cooled XRs and ATCs and we would putt putt these things around in the woods for hours with almost no air passing over the motor. Even today I have a 94 FourTrax 200D that still runs the original factory spark plug and centrifugal clutch. Just change the oil, often.

I would agree, except that Honda only designed a 125cc engine. The bore and stroke increase and increased power through a thinner cylinder body (thanks to the larger bore) also means these engines don't manage heat as well as the original Honda design. Is it 100% needed? No. Is it beneficial, yes. Especially considering the price of a kit is usually around $60-80 delivered.

For those of us who have bumped up our compression ratios and increased the specific output of the engine by 20-30%, heat is definitely an even greater consideration. Taller gearing also puts more load on the engine through each gear.

This is coming from somebody that is more obsessive about maintenance and oil changes than probably anybody else here. My last Hawk's oil got changed more often than my underwear

[OneLeggedRider]

Originally Posted by Megadan

I would agree, except that Honda only designed a 125cc engine. The bore and stroke increase and increased power through a thinner cylinder body (thanks to the larger bore) also means these engines don't manage heat as well as the original Honda design. Is it 100% needed? No. Is it beneficial, yes. Especially considering the price of a kit is usually around $60-80 delivered.

For those of us who have bumped up our compression ratios and increased the specific output of the engine by 20-30%, heat is definitely an even greater consideration. Taller gearing also puts more load on the engine through each gear.

This is coming from somebody that is more obsessive about maintenance and oil changes than probably anybody else here. My last Hawk's oil got changed more often than my underwear

Well like I said, I wouldn't find fault with anyone installing an oil cooler, and on a modified Hawk I would probably recommend it. I have a '74 3/4 ton Camper Special K20 that I compete with. The factory went overboard on this truck, a 4 core radiator with trans cooler, plus an additional trans cooler in front of that, and an oil cooler in front of that! I'm lucky if this thing ever reaches 170° and it does foul plugs. But the original motor has lasted 45yrs. It's also completely stock, from the breather to the exhaust manifolds.

[upgasgas1224]

what effect would a oil cooler going into the screen port and also a oil cooler into the valve cover do vs two oil coolers to the screen port my guess is it would cause a better cooling effect ? and possibly better lubrication?

[Megadan]

Originally Posted by upgasgas1224

what effect would a oil cooler going into the screen port and also a oil cooler into the valve cover do vs two oil coolers to the screen port my guess is it would cause a better cooling effect ? and possibly better lubrication?

I considered that exact setup. The oil flow to the head comes straight from the pump and up the right rear head/cylinder stud to the valve cover anyway, so the difference would be fairly minimal. If you wanted the most direct cooling then it would be the way to go though.

[Weldangrind]

I'm no rocket surgeon, but I have my concerns about running two coolers. It strikes me that there would be some loss in pressure with that much of an oil circuit, which the pump wasn't designed for. It may not be a concern at all, but I'd stick to one cooler.

[JerryHawk250]

Originally Posted by Weldangrind

I'm no rocket surgeon, but I have my concerns about running two coolers. It strikes me that there would be some loss in pressure with that much of an oil circuit, which the pump wasn't designed for. It may not be a concern at all, but I'd stick to one cooler.

I'm thinking about installing an oil pressure gauge. Not sure were would be the best place to take a reading from?? Bolt on top of valve cover maybe?

[ChipToothy]

I’m looking on amazon for the same cooler. Do we need to add more oil to the engine to maintain the 50/50 level on the glass or just plug and play. Seems like increasing the volume of oil passing through is just what the doctor would have ordered for these motors.

[JerryHawk250]

Originally Posted by ChipToothy

I’m looking on amazon for the same cooler. Do we need to add more oil to the engine to maintain the 50/50 level on the glass or just plug and play. Seems like increasing the volume of oil passing through is just what the doctor would have ordered for these motors.

Yes it will require a few more ounces of oil.

[ChipToothy]

Originally Posted by JerryHawk250

Yes it will require a few more ounces of oil.

Another +1 for the oil coolers then!

[Megadan]

Originally Posted by Weldangrind

I'm no rocket surgeon, but I have my concerns about running two coolers. It strikes me that there would be some loss in pressure with that much of an oil circuit, which the pump wasn't designed for. It may not be a concern at all, but I'd stick to one cooler.

It really isn't a concern. The coolers most of us run are rather small in internal volume. - 65ml to be exact. The largest cooler designed for these engines is almost 3 times that size at 170ml. Plus, the usual pressure drop across most fluid coolers is rather minimal. Being such a short tube length and overall small size, the pressure drop across one of these oil coolers is likely no more than 2psi, and likely less.

My personal issue with the kits, specifically the sump system, is the length of the cooler lines. IMHO they are too long, especially considering they have to pump up hill already. Running a line length just long enough to get to the cooler and back will reduce flow restriction. This is an area where we have control over the pressure drop.

Originally Posted by JerryHawk250

I'm thinking about installing an oil pressure gauge. Not sure were would be the best place to take a reading from??

For system pressure, the best place would be on the return side of the system before it goes back into the engine as close to the fitting as you could manage. This would be more indicative of the pressure the rest of the system is seeing as it is pumped through the engine after any potential pressure drop from traveling through the lines and cooler(s).

[upgasgas1224]

Originally Posted by Weldangrind

I'm no rocket surgeon, but I have my concerns about running two coolers. It strikes me that there would be some loss in pressure with that much of an oil circuit, which the pump wasn't designed for. It may not be a concern at all, but I'd stick to one cooler.

I questioned that too i wonder if theres an upgraded oil sump

[JerryHawk250]

I've been running the oil cooler for over a year and a half. I think if there was any kind of issue something would of happened by now. Oil must be flowing well enough as the oil temps hang around the 130-150 range which are on the low end. I think you guys in the northern part of the US where the temperatures get much colder would probably be better off with just a single cooler. Down south our winters are milder but summers are extremely hot. That's where the dual coolers really help.

I would like to install a oil pressure gauge just for a piece of mind.

[upgasgas1224]

Im more than likely sticking with just the one just was wondering what the difference between two coolers how you have it jerry or one cooler to the screen port and one cooler to the valve cover would be my judgement would be better localized cooling

[JerryHawk250]

Originally Posted by upgasgas1224

Im more than likely sticking with just the one just was wondering what the difference between two coolers how you have it jerry or one cooler to the screen port and one cooler to the valve cover would be my judgement would be better localized cooling

I don't see why it wouldn't work any better. You would be cooling the oil before it reaches the head with the valve cover unit and then again with the screen port unit before it returns to the base. I'd say do it.

[timcosby]

ive been thinking one oil cooler and one oil reservoir for additional oil. installed on fabricated engine guards. by the way those engine guards work well most of the time. i took an exit in gadsden in the pouring rain was carrying a little too much speed for conditions and was braking my harley ultra classic tank of a bike. well about mid curve hit a small repair bump and down we went. bike was sliding away from me as i was sliding and im looking thinking man those guards are great there doing their job well. then it slowed down enough for the tires to catch and flipped the bike to the other side and over past where the other guard would have helped. not too bad busted a latch and cracked the lid on the tour pak in five places two large scrapes on the front of the fairing and bent one light. got it off now and dismembering it to do the fiberglass work. light will bend back out and i got a new ring for the turn signal. i had tools everywhere across the road. clothes here and there. it was a sight.