oil cooler

[SydneyChris]

Purchased a small engine oil cooler (300 x 150) and oil pump take off with AN10 lines from VPW.

I wasnt happy with the take off pattern on their engine fitting so I grabbed the one as per the pic included that enabled better pipe routing.

There is a statement in the item description advising that the fitting must be installed with 'inline restriction'.

Not clear why you'd have AN10 fittings and lines too and and from the cooler then add inline restriction or how this would be installed. (AN10 - AN6 adaptors to form a choke point..?)

Look forward to some advice before creating any expensive engine issues..

[renovationinnov]

chris
I was looking at this as well & rang them they are talking about a thermostat control valve
hope this helps
rob

[SydneyChris]

ohhh.. so its around oil temp.. not pressure or pump capacity then... thanks Rob

[Modena]

Originally Posted by SydneyChris

ohhh.. so its around oil temp.. not pressure or pump capacity then... thanks Rob

Sort of. The oil temp is used with a thermostat to direct the oil to and from the cooler. The thermostat should be put in so that temp comes up quickly (relative), but look at any oil thermostat and it has a bypass/return valve, so oil goes out of your adapter and into thermostat, while thermostat is "cold" oil does not go to cooler but instead goes back to engine - obviously this is the purpose of the thermostat. Different thermostats will work in different ways, I use an Improved Racing one (google it), and it's bypass is "open" when cold, therefore due to the lower restriction in this shorter path 90% of the oil goes back to the engine without going through the cooler. As it heats up the bypass closes and more and more oil goes through the cooler.

I think by "restriction" they are referring to a thermostat.

[Modena]

sorry rob, didn't see your message before replying

[SydneyChris]

Thanks Modena... is clear now.. looked up Improved Racing, EGM112 (LS engine unit) is around $340 delivered from Amazon.

Anyone need an oil cooler adapter plate as per the initial pic..?

[Modena]

I am using one of the stand-alone thermostats that look like this, but if you have the front-hump sump then yes you can get an adapter which is also the thermostat.

I have an aftermarket sump which means I already have provision for cooler lines, I just needed the thermostat

[Aussie Mike]

Another thing to think about with an oil cooler and thermostat is adding a check valve into the return line from the cooler. The reason for this is to reduce the chance of splitting the cooler with cold oil under high pressure being fed back from the motor on start up.

The galleries of the oil cooler can be quite restrictive to cold oil due to it's higher viscosity. When the engine is cold and the thermostat is closed it is only diverting flow from the engine away from the cooler. The other side of the cooler is still connected to the oil gallery where it feeds oil back to the motor. This is still under pressure and cold engine oil pressures can also be quite high (we have pressure but not flow if that makes sense).

A check valve in this line from the cooler to the engine stops the pressure reaching the cooler until the thermostat opens and oil starts flowing through it.

I'm also set up with an accusump so that when you turn the key it pre-oils the motor. The check valve also helps ensure the oil flows from it to the motor and not towards the cooler. I've since changed the valve in this pic for a full flow swing gate style check valve.



Cheers

[SydneyChris]

thanks Mike,

With the Improved Performance unit bolted to the oil pump outlet on the block, the bypass would happen at that point on start up unless the unit didnt have time to cool between runs.

This being the case it would appear the risk mitigated as only warm oil can get to the cooler..?

Chris

[bobcowan]

Any good oil thermostat will allow about 10% of the oil to flow through the cooler when cold. That allows all of the oil in the system to warm up at the same rate. Otherwise, once the main body of oil allowed the thermostat to open, you'd get a sudden slug of cold thick oil into your engine. That's a bad thing. of course, on a cold morning, the oil temp may never get to operating temp.

When fully open, the thermostat bypasses about 10% back to the engine. The cooler and lines will create some restrictions; the bypass helps to maintain good flow in a hot engine. It also helps prevent high pressure waves through the cooler with a sudden rise in rpm's.

[SydneyChris]

thanks Bob.. and all I wanted to do was cool the engine.. lol..

Is frustrating at times how little I know in practice after a lifetime of loving and working on cars. Building one from scratch is a completely different ball game.

Appreciate the advice..

Chris

[Rob. Smith]

Just a thought...In Australian climates...would the thermostat be necessary ? With the correct oil weight . I doubt there would be much of a change in viscosity . Correct me if I'm wrong. The pre-start oil accumulator is a good insurance.

[SydneyChris]

There is a significant change with temp Rob over what would be normal Aussie conditions

Chart included below for 5W40 over a 100C range.

[bobcowan]

That is true. Oil viscosity drops as temperature climbs. Oil also breaks down the longer it is exposed to heat.

Oil is predominantly heated by RPM's. extended rpm's that you'd see in road racing. street and highway driving generally don't create enough heat to worry about, except in the most extreme desert conditions.

For most street cars, oil temp tends to hover right around coolant temp.

Oil has a minimum operating temp, too. It's really hard to find out what that number is, as manufacturers are not willing to let that be known. But it seems to be around 180*F. Perfect operating temp seems to be right around 200-210*. In a race car, it will usually be between 300-350*.

I often drive when the temps are pretty cool. I found that even with a thermostat it was sometimes impossible to get the oil up to operating temps, even when the cooler was covered.

If your oil temp is consistently above 250*'ish, then it's probably worth it to install a cooler. Otherwise, use a true synthetic and don't worry about it.

[Modena]

I have an oil cooler because it looks cool

[guye]

Originally Posted by Modena

I have an oil cooler because it looks cool

LOL Ben! You idiot! Love it!

[deano59]

ive just put a oil temp sender into the side of the sump on my race car only a small 253 raced on dirt but ive been thinking for a while about oil temps and putting a cooler in the system at least i can find if it's worth the effort now i will be able to find out out what temp it will be running at ...in the scheme of things there not that expensive to set up and if you track your car from time to time a cooler is prob a good investment ..

[Aussie Mike]

I'll have to go back and check my plumbing again. It's been so long since I set it up.

[ICCARS]

Originally Posted by SydneyChris

Purchased a small engine oil cooler (300 x 150) and oil pump take off with AN10 lines from VPW.

I wasnt happy with the take off pattern on their engine fitting so I grabbed the one as per the pic included that enabled better pipe routing.

There is a statement in the item description advising that the fitting must be installed with 'inline restriction'.

Not clear why you'd have AN10 fittings and lines too and and from the cooler then add inline restriction or how this would be installed. (AN10 - AN6 adaptors to form a choke point..?)

Look forward to some advice before creating any expensive engine issues..

Hi Chris,

I am 99% sure that the inline restriction is to ensure that the oil pump doesn't run the sump dry.
I ran a thermostatically controlled oil bypass to a cooler for my Twin turbo GT40 engine and noticed a drop in idle pressure when the engine was hot, so I removed it as I already run an oil cooler post turbos back to the engine via a scavenge pump set up, so I would presume that this would be the case with this set up also when using a standard volume oil pump.

P.S. my engine also runs an adjustable pressure high volume oil pump, and I run a 7qt HV sump, so the only way I was bleeding off pressure would have been through the additional bypass volume, so just be careful if you are using this set up with a standard volume oil pump.

Cheers

[Gaz64]

Any "restriction" as in a predetermined additional orifice like a carb main jet etc placed inline to an oil cooler would simply lower the maximum pressure that can buildup in the system after the oil pump.

So if you do this, your oil pressure gauge sender and warning light switch, cutouts etc need to be after the cooler which is then truly sensing engine oil pressure, and not at the oil pump.

Myself, if my engine runs 80 psi cold, then a cooler that is pressure tested to say 200 psi should be enough.

A thermostatic bypass valve allows a small amount of oil to circulate through the cooler as the engine warms, and gradually opens to take more of the flow through the cooler as the oil temp increases.

Allows fast oil temp warm up to, and controlled temps under adverse conditions.

I rather run a custom sump and pickup, trapdoors etc, and run a little less than most do in the engine.

This allows the oil in the engine sump to warm up faster and boil off the acid from each cold start.

My 2 cents.

Gary