??Oil cooler up front??

[Forever-Fiero]

I got a RX7 oil cooler from the J-yard and was thinking of a good place to pit it. Well the only good place is were it belongs, UP FRONT. This makes for a long oiling system. about 12 extra foot. :scratch: Think if run 1/2" hard line I can get away with It? I know it will drop psi but don't know by how much.

[Shaun41178(2)]

Mount it in the wheel well underneath the battery. Thats where I put mine. It doesnt' have to get direct airflow for it to cool the oil. It will still act as a heatsink you know

[Forever-Fiero]

I never thought of it that way. Thanks :salute:

[MstangsBware]

I have been thinking of adding a fuel cooler to my setup and thought about this same area.

[Shaun41178(2)]

Hotter fuel burns more efficiently because it vaporizes easier. Vaporization allows a cleaner more efficient burn. more fuel burnt, the more power you will make.

[The Dark Side of Will]

However, the hotter the fuel is, the closer it is to detonation.
The colder it is, the more evaporative cooling you get as it goes into the chamber... just a smidge more detonation resistance.

[Shaun41178(2)]

simple solution, keep the air cooler. :thumbleft:

[MstangsBware]

Hotter fuel burns more efficiently because it vaporizes easier. Vaporization allows a cleaner more efficient burn. more fuel burnt, the more power you will make.

The thought of adding a cooler to the fuel was how hot my fuel rails get. After adding some ZZP billet rails I started hitting them with the heat gun. They get up to 175* in a short period of time. Not forsure what the actual fuel temps are getting up to but sure its close.

[Atilla the Fun]

The injectors run plenty warm, the fuel must not turn to vapor before it gets to the injectors. Vaporlock is part of why they made MPFI run at 39 or so psi when TBI had been running at 12 psi. Even at 58 psi, if the fuel line gets hot enough, the fuel will vaporize, then you're stalled. This is why some MPFI cars run a cool can, (not from the factory, though) which was originally invented for carbureted cars.

[The Dark Side of Will]

Hotter fuel burns more efficiently because it vaporizes easier. Vaporization allows a cleaner more efficient burn. more fuel burnt, the more power you will make.

The thought of adding a cooler to the fuel was how hot my fuel rails get. After adding some ZZP billet rails I started hitting them with the heat gun. They get up to 175* in a short period of time. Not forsure what the actual fuel temps are getting up to but sure its close.

The injectors run in pretty intimate contact with the engine, which has its temperature controlled at 195 degrees or so.
The injectors, fuel pressure, etc is all spec'd appropriately and the car has been torture tested far more than we could ever do with it.

[Zac88GT1]

I got a RX7 oil cooler from the J-yard and was thinking of a good place to pit it. Well the only good place is were it belongs, UP FRONT. This makes for a long oiling system. about 12 extra foot. :scratch: Think if run 1/2" hard line I can get away with It? I know it will drop psi but don't know by how much.

Lotus does it. I just finished helping a friend put a 2000 N* in his 89 Esprit turbo. Stock the esprit comes with the oil cooler in the front and it uses flexible hose the whole way with a diameter of 5/8". It probably adds a substantial amount of oil capacity as well.

[Aaron]

While it adds capacity, that isn't completely usable capacity. So while it will aid in controlling oil temperatures, it doesn't do anything for extending the pickup quantity available.

[The Dark Side of Will]

More oil capacity = lower oil temps. Dump X watts of heat into 1 gallon of oil or 2 gallons of oil... which way is going to result in lower temps?

The rubber hose also helps dissipate more heat.

Personally, I prefer oil/water heat exchangers. They warm the oil up faster than a cooler, yet keep it within 20 degrees of coolant temp.

[Atilla the Fun]

yeah, but with the cooler up front that's about 4 more quarts to change, at $5/qt for good synthetic. Are you sure you abuse your car enough to warrant a cooler?

[THE PUNISHER]

911's have em upfront too , even watercooled ones...

lotsa corvair guys run them up front...

I have a massive Oilcooler in the vair with a thermostat.. keeps everything nice and new

[Aaron]

More oil capacity = lower oil temps. Dump X watts of heat into 1 gallon of oil or 2 gallons of oil... which way is going to result in lower temps?

The rubber hose also helps dissipate more heat.

Personally, I prefer oil/water heat exchangers. They warm the oil up faster than a cooler, yet keep it within 20 degrees of coolant temp.

I understand that Will, that's why I said it will aid in controlling oil temps. However, the added capacity will be more beneficial if it is in the form of a larger pan.

That's what I have on my car, an oil/water. I routed the coolant hoses to it differently than stock however. Stock, the water that feeds the cooler is sent to it after it has gone though the engine, so it is warm. After the cooler, it returns to the coolant supply right before the water pump, so it doesn't go to the radiator. This helps warm the oil up quicker, however doesn't cool it as efficiently.

On my motor, with 1.5qts added capacity, I have the coolant feeding the oil cooler prior to it going through the engine, so it is at the coolest point in the system. After the cooler it Y's with the water from the turbo to feed the heater core. So while my oil will take longer to heat up, it will theoretically be kept cooler due to the capacity and the more efficient water routing.

However, I'm considering changing it back to stock. I do not anticipate any oil temperature problems, especially with the oil/water cooler and the added capacity, despite the turbocharger (Which is less of an issue because it's water cooled, and BB). So I may go back to the stock way so my oil warms up faster. Plus I want to switch back to a mechanical pump.

[The Dark Side of Will]

Well, there's the question of dissipation of the heat as well. It doesn't disspiate heat efficiently sitting in your enlarged pan.

Like I was trying to get across above, oil temps are the balance of waste heat from the engine and heat dissipation from any cooling mechanisms. In older cars that were less dense, airflow over the oil pan was adequate oil cooling. Modern cars with higher power densities require more. So for a given heat flow through the oil system, increasing the oil quantity will reduce oil temperature. Duh. However, with limited dissipation capacity, oil temps will get really high no matter how much you have.

Lesson: don't @$$ume it's doing you any good just sitting there in the bottom of your oil pan.

Also, the difference in water temp from the cold side to the hot side of the coolant circuit is usually <10 degrees. Water is an excellent coolant due to its high specific heat. The affect on your oil temp is tiny.

[Aaron]

Very true on all accounts.

I wonder what affect welding cooling fins on the pan would have. Worth the trouble? I won't do it because I doubt highly I'll have any oil temp issues, and don't want the weight, but it's another idea. And with my pan hanging below the cradle, and the Fiero's poor underbody airflow (Meaning there's lots), I bet my pan air cools pretty well.

Only 10*? I would have thought it'd be more like 30-40. Hmm. So the affect on my oil from that would be beyond minimal. I'm going to go back to a mechanical pump, and stock hose routing the day after my dyno pull. I don't trust the electric water pump.

[Forever-Fiero]

Are you sure you abuse your car enough to warrant a cooler?

Oh yess!! I will be using the full benefit of this cooler. I have a TGP 3.1 with a t3. turbos make for lots of heat in the oil so its needed. Im thinking water to oil to get the oil up to temp then air to oil after to not get to hot. idk just a thought. Thinks for all the input. and I even got some bones info on fuel!! :thumbleft:

[Aaron]

Why not just stick with oil-water? It will be plenty capable of handling your build. Plus it will weigh less, have much less places to leak, and overall be more reliable.

Plus, you can get one from a 3.4 DOHC, and it will bolt on easy. Pull it off the DOHC, put it on your motor. It's easy as that, it fits right between your oil filter and block, and bolts on easy. Plus it'd cost all of $10 from a junkyard.

You will need to be pushing some serious boost (Over 18psi), or serious rpm (Over 7000), to overheat your oil with the DOHC cooler on it.