Bolt on no mods oil cooler? Any intrest?

[mjstef]

More awake this AM, Would not siphon as the squirt holes over the rockers would suck air 1st............

['16 TT250]

Originally Posted by mjstef

More awake this AM, Would not siphon as the squirt holes over the rockers would suck air 1st............

Exactly why it can syphon. Air easily enters the cooler system through the holes allowing the oil to be sucked down towards the sump through the other hose. Since the squirters will have little restriction on the air being pumped through them, at start-up it'll starve the whole system for pressure until oil reaches the squirters again. If the cooler inlet is on the lower hose it could drain the entire cooler. If the inlet is on the upper hose it'll likely trap air in the cooler; among other potential problems with that will be the unpredictable oil levels in the case.

If I were going to install one, which I likely won't; I would plumb the inlet to the lower cooler hose and use a check valve, no drain-back and no trapped air. I would also pre-fill the cooler and hoses before the first start-up. After the install I would check the oil level regularly before starting to assure it's not draining back.

[Weldangrind]

Originally Posted by kohburn

and on V engine configurations there is a PCV to generate one direction of airflow through the crankcase drawing fresh air in through one bank and out through the other.

the outlet goes to the engine intake to burn the oil mist and fuel vapor for emissions elimination.

you don't want to build pressure or draw a vacuum in the crankcase or you will cause seals to fail.

Thank you, Kohburn; I failed to mention that part.

I do like the concept of creating a vacuum in the bottom end of V8 motors in drag racing applications, but I don't know what the long term reliability would be.

[mjstef]

Originally Posted by '16 TT250

Exactly why it can syphon. Air easily enters the cooler system through the holes allowing the oil to be sucked down towards the sump through the other hose. Since the squirters will have little restriction on the air being pumped through them, at start-up it'll starve the whole system for pressure until oil reaches the squirters again. If the cooler inlet is on the lower hose it could drain the entire cooler. If the inlet is on the upper hose it'll likely trap air in the cooler; among other potential problems with that will be the unpredictable oil levels in the case.

If I were going to install one, which I likely won't; I would plumb the inlet to the lower cooler hose and use a check valve, no drain-back and no trapped air. I would also pre-fill the cooler and hoses before the first start-up. After the install I would check the oil level regularly before starting to assure it's not draining back.

On the supply side what is the likelyhood it could suck back through the oil pump? If that's the case the engine would always start dry anyways. On the outlet side it has the squirt holes. Mountain out of a molehill IMHO. I ran a diesel performance shop in Florida for many years and we routinely took check valves out of the Dodge 47RE transmissions to provide more oil flow to the cooler. This is well documented and many forums and it worked. I would think if their was going to be any issue, Wolftrax with over 2,000 miles on his cooler would have had them. That said, If you are bothered, A Banjo Bolt check valve is available for $20. https://blaisracingservices.com/ktm/...mog-p1270.html

[Weldangrind]

Originally Posted by Ariel Red Hunter

You may be right on the subject of crankcase pumping. All I can say in defense of my position is that's the way its been done for over a hundred years on single cylinder engines. And V-twins as well. But those engines were either total loss oiling or dry sump. It is possible that it is no longer neccessary with wet sump engines. Lower crankase pressure reduces oil frothing and pressure leaks from the seals. Not to mention air pumping losses from moving 1000 cc of air for every firing impulse. To pump air takes power which we want to use for other purposes. Don't worry about lack of air in the crankcase, plenty of air gets in there during the power stroke. It gets past the rings under compression and from gas pressure. It was found long ago that all of that air whistling through the innards of an engine caused power losses due to oil swirling. Pumping aerated oil (oil mist) takes even more power than pumping pure air. Why? Because it is heavier.

Honestly, one of my favourite aspects of this forum is the terrific technical discussions we have. Thanks for sharing your interesting thoughts.

[kohburn]

I really think drain-back is a not issue. the hawk motors have had the simple cooler installed with only positive effects.

[BlackBike]

Msjft.. as far as the can't be done folks, I say this is good to talk it out and Bulletproof the design. One thing I might add in your development, could you use the transparent hose to observe the oil during the initial start/flow process. It wouldn't even need to be run long so the heat on the hose would not be relevant for the short testing period . With the ability to see what the oil is doing you could best position the cooler/ hose routing etc.

1 in. x 3/4 in. Vinyl Braided Tubing or equivalent? They have heavy duty fuel rated versions too.

[Ariel Red Hunter]

Yes, I enjoy them as well. I learned 90% of what I know from playing with BSA Goldstars, AJS 7R's, and Aermacchi Harley Davidsons. And I learned what NOT to do on my Ariel Red Hunter and My Ajay 350. The Aermacchi was great - a whole different approach to getting the same result. First at the checkered flag. I wasn't a good enough rider to win, although I loved racing in Southern California TT races. Prado Park was my favorite track to race on. A fast, but nasty dirt road racing track. I don't mean dusty I mean nasty like the kind of pitches that Clayton Kershaw or Jake Arrieta throw.

Originally Posted by Weldangrind

Honestly, one of my favourite aspects of this forum is the terrific technical discussions we have. Thanks for sharing your interesting thoughts.

['16 TT250]

Originally Posted by mjstef

On the supply side what is the likelyhood it could suck back through the oil pump? If that's the case the engine would always start dry anyways. On the outlet side it has the squirt holes. Mountain out of a molehill IMHO. I ran a diesel performance shop in Florida for many years and we routinely took check valves out of the Dodge 47RE transmissions to provide more oil flow to the cooler. This is well documented and many forums and it worked. I would think if their was going to be any issue, Wolftrax with over 2,000 miles on his cooler would have had them. That said, If you are bothered, A Banjo Bolt check valve is available for $20. https://blaisracingservices.com/ktm/...mog-p1270.html

Extremely likely that it would drain back through the pump. If oil pumps didn't allow oil to drain back through them we wouldn't need the check valve that's fitted to every oil filter. In stock configuration there may be a couple ounces in that circuit, the cooler will add a lot of volume that has to refill extending the dry run duration by a large percentage. Easy way to know if it drains; let a stock bike sit overnight and remove the valve cover, if that circuit isn't still full it drained. If it did drain it'll also drain the cooler circuit until the syphon breaks. I don't know the construction of these motors; if they use roller type bearings on all the friction points then the dry start will have little impact, if they're plain pressurized bearings it could cause quite a bit of wear.

The transmission comparison has no relevance.

[Ariel Red Hunter]

Caged ball bearings on the crankshaft, caged roller on the big end bearing.

Originally Posted by '16 TT250

Extremely likely that it would drain back through the pump. If oil pumps didn't allow oil to drain back through them we wouldn't need the check valve that's fitted to every oil filter. In stock configuration there may be a couple ounces in that circuit, the cooler will add a lot of volume that has to refill extending the dry run duration by a large percentage. Easy way to know if it drains; let a stock bike sit overnight and remove the valve cover, if that circuit isn't still full it drained. If it did drain it'll also drain the cooler circuit until the syphon breaks. I don't know the construction of these motors; if they use roller type bearings on all the friction points then the dry start will have little impact, if they're plain pressurized bearings it could cause quite a bit of wear.

The transmission comparison has no relevance.

[mjstef]

10 mile ride this afternoon at 92* ambient temperature. Case temp 215* Cylinder temp 245* when i got back, Cannot get the bike into neutral without shutting it off or going back and forth from 1 to 2 10-15 times and getting lucky. Running 1/4" Clutch free play. DO NOT have this issue when it's in the 50's. That is why i started looking into this in the 1st place. I just think heat is expanding things enough to cause this. Bike has a little over 300 miles on it. The other bike from the 2 pack i bought does the same thing..........

[SeerAtlas]

maybe its old school, but i was taught always to shift into neutral as i rolled to a stop, the idea being having the clutch suddenly bind, or a cable let go, you wouldn't be launched out into traffic or an intersection- which could b baaad accordingly, I haven't noticed any neutral problems on either of my Hawks to date.

[mjstef]

Originally Posted by SeerAtlas

maybe its old school, but i was taught always to shift into neutral as i rolled to a stop, the idea being having the clutch suddenly bind, or a cable let go, you wouldn't be launched out into traffic or an intersection- which could b baaad accordingly, I haven't noticed any neutral problems on either of my Hawks to date.

It will do it rolling reasonably well. Problem off road in the mountains is their is not a lot of rolling to a stop lol. Lot of 1st gear work. I just hate holding the clutch in while maneuvering down a tight single track. Would rather be in neutral walking it down carefully. Too damn old to spill it lol!

[mjstef]

Actually just ordered a 13 tooth for where i ride.....

[C Renner59]

I'm in for the oil cooler it make very good sense to me.