Oil cooler in radiator

[BSG]

I'm using a yamaha FZR1000 engine that is both water and oil cooled.
To save having to mount both a radiator and an oil cooler I'm looking at using a small car radiator from an auto so it has an internal oil cooler.
Any body ever done this???
There are three problems I can see
1. when the engine is off, no oil pressure so the oil will drain back into the sump.(oil fittings in the rad are at the bottom)
2. when started all the oil being in the sump could cause internal motor damage.
3. delay between start up and oil being pumped back through the system will mean the engine runs without the benifit of lube for a brief time.

Possible cures.
1. run the oil line up higher than the top of the cooler so oil is trapped in the cooler when engine is stopped. but the extra height may mean I loose some oil pressure.
2.oil thermostat so on start up oil bypasses cooler and goes straight back to motor. All the oil thermo's I've seen allow 90%back to motor and 10%to fill and pressurize the cooler till the motor gets upto temp then allow all the oil through the cooler.
3.Electric solenoids on inlet and outlet activated by an oil pressure switch on the motor outlet. Start motor pressure switch open the soleniod allowing the oil to flow through the cooler- Motor stops, no pressure solenoids close trapping oil in the cooler. Warning lights wired to each solenoid.
4. Pressure valve on inlet/outlet to open when motor runs- close when motor is off.

Any suggestions or experiences of using car radiators with internal oil cooler would help. *[smilie=banghead.gif]

[Bugpac]

can the oil run back in a system designed for a cooler?

[renegadespec1]

Is the motor wet sump or dry sump? I don't think that the oil pressure would be that much higher than the trans fluid. But they make oil coolers that run piggy-back on the radiator, so you wouldn't have to find frame space elsewhere on the frame work, I've never tryed this so it's just a guess

[BSG]

wet sump.
I could mount a seperate oil cooler piggy back style.
Does it matter which direction the inlet/outlet face - up-down-out the side?

[renegadespec1]

I Think the in put and outlet shold be horizontal that's how they are mounted in race cars

[Rorty]

Originally Posted by BSG\";p=\&quot

Does it matter which direction the inlet/outlet face - up-down-out the side?

Not really. As you pointed out in your PM, I mounted the oil cooler on my R5 with the unions facing down, but that was more because I had those particular fittings and just that length of hose at hand. I've heard the argument of the possibility of air pockets forming in downward facing coolers, but I never experienced any problems with that installation.

Most modern bikes have very efficient oil pumps and with synthetic oil, there's no chance of engine damage even if the engine has been left standing for a while.
A cooler can be mounted upwards, downwards, on its side or whatever – positioning is of more importance and is something worth spending a little time contemplating.

Obviously the oil cooler requires a good through put of cool air to function, but if the cooler is placed in an open location (but within the confines of the chassis), then it stands a fair chance of being clogged with roost from other buggies.

A good location is right in front of the radiator where it should be fairly well protected and as long as it's virtually touching the rad, there will be no air turbulence between the two and the heated air from the oil cooler will have next to no effect on the radiator's performance. Don't let the two coolers actually touch as harmonics in the chassis could easily lead to ruptured cooling tubes.

When mounting oil coolers or electric fans to radiators, there are proprietary plastic fittings that pass through the rad's fins and often come with new rads, but if purchasing them as a separate kit, they're expensive for what they are. I use ordinary 6mm (1/4") cable ties (tie wraps?) and some old plastic oil bottles (the thicker ones) which perform the same function.

I split an oil bottle open and cut eight 25mm (1.0") circles with a wad punch (scissors will do) and punch a 6mm hole in the centre of the discs. Next I cut the heads off four of the cable ties and throw the tie parts away.

Support the fan/oil cooler where you want it making sure there is some insulation between them and the rad (several more plastic discs can work). Thread the points of four cable ties through four of the plastic discs and thread each tie through the rad and fan/cooler. Slip the remaining discs over the ends of the cable ties at the back of the fan/cooler and then slide the four cable tie heads down the ties and snug them against the plastic discs. Voilà!

Another alternative is the very efficient Laminova cooler which combines an inline air water to air cooler with an inline oil to air cooler and is extremely compact.

Which ever route you take, make sure you have sufficient oil cooling as it's a much more efficient method of cooling the engine than a water to air radiator.

[BSG]

Thanks for the reply Rorty.
Based on your reply it's ok for the fittings to be at the bottom.
So if I was to fit a car Radiator with in built oil cooler it should be Ok so long as the in built cooler was larger than what was originally fitted to the bike.

'IF' all of the oil drained from the cooler back into the motor could that cause damage to the motor on start up. *[smilie=big_explode.gif]
I also plan on fitting as large as possible fan running constantly to keep everything cool

[Rorty]

Originally Posted by BSG\";p=\&quot

Thanks for the reply Rorty.
Based on your reply it's ok for the fittings to be at the bottom.
So if I was to fit a car Radiator with in built oil cooler it should be Ok so long as the in built cooler was larger than what was originally fitted to the bike.

In a buggy, it's prudent to fit a larger oil cooler than that fitted to the bike because on a bike, space is at a premium and the cooler efficiency (size) can be little better than marginal and you'll be giving the bike engine a lot more work to do in the buggy. Harder qork = more heat. *BUT, you can over-cool the oil to the extent where the engine doesn't reach optimal operating temperature and then, apart from not attaining peak performance, the engine will start fouling plugs etc. etc. etc. If the cooler (trans cooler?) in your car rad is a lot bigger than the bike's OEM cooler (think capacity, not external dimensions), then consider installing an in-line thermostat to keep the oil at the right temp.

Originally Posted by BSG\";p=\&quot

'IF' all of the oil drained from the cooler back into the motor could that cause damage to the motor on start up. I also plan on fitting as large as possible fan running constantly to keep everything cool

No, no! A hard wired fan is not an efficient way of cooling and just because it's bigger doesn't mean it's going to draw greater amounts of air through the rad. The same applies to fans as coolers - you can over-cool the engines coolant. Also, sometimes mis-matched fans (small/lower rated motor) cause overheating because the fan actually obstructs the airflow.

I know, I know, what do you do?
Well, I'd start with a "reasonable" sized fan and hook it up to a thermo fan switch in the radiator and ensure it's heat range matches the one in the bike's rad (the value should be given in the bike's workshop manual).

[bdkw1]

Originally Posted by bugpac\";p=\&quot

can the oil run back in a system designed for a cooler?

In order for you to have drainback from a cooler you would have to have some way for air to get into the system. Unless you have a serious leak in one of your hoses this will not be a problem, actually at that point it would be the least of your worries.