Could it be done? Is it a good idea?

Merlin · Post by **Merlin** » Fri Dec 07, 2007 2:57 pm

Just had a thought...Hot'ed up engines...specifically those with a fair amount of work in them, and revving higher than stock...

For example...my new engine is estimated to rev max. at 5,300 - not done yet.

Obviously having all of your tinware is a good idea. I'm using a new early-style 'Doghouse' shroud, but the flow inside has been redone by CB.

There is a mount on the back, obviously, for the oil cooler.

Could you mount a second oil cooler on the right side, and join that flow with the stock one on the left?

Would it be of any use?

N.

Post by **Tony Z** » Fri Dec 07, 2007 3:26 pm

I can see that thinking hurts.... so please dont do it anymore.

forcecooled · Post by **forcecooled** » Fri Dec 07, 2007 3:39 pm

Not feasible.

Look at the design of the ducting in the fan housing and you will see how the airflow to the cooler (doghouse) is achieved with minimal disruption to the flow to the rest of the motor's components.
The doghouse arrangement is the best improvement VW ever did to the upright motors.

Even on the normal single port motors , it is a good idea to fit doghouse components. Keep the original bits for originality's sake, but fit the DH stuff !

Chaars
Bill

Merlin · Post by **Merlin** » Fri Dec 07, 2007 5:11 pm

'k, thanks.

Riftvalleyvw · Post by **Riftvalleyvw** » Fri Dec 07, 2007 6:54 pm

Do you mean that there is a mounting bracket on the back of the shroud for mounting an oil cooler?? Outside of the doghouse? Hmmm Never seen one but it is not a good Idea. The heat from the oil coller will just be sucked into the fan. If you are talking about the 2 bolt hole inserts in near the doghouse, they are mounting holes for the tin to divert the air out of the engine compartment. If you only got the shroud, you will also need that tin piece, a hooverbit and the rear engine tin that has the outlet for the doghouse cooler. If you dont install these pieces the hot air from the oil cooler will just circulate and your motor will overheat.

The stock doghouse oil cooler is rated at about 8,000 BTU with a 26mm oil pump. If you install a 30mm oil pump it will remove almost 15,000 BTU without adding an external oil cooler. But to get any effect with a 30mm oil pump, you will need to enlarge the relief holes in your case. If you have a single relief case, you are out of luck for more cooling. You really need a dual relief case to get any benifit.

Merlin · Post by **Merlin** » Fri Dec 07, 2007 9:48 pm

OK, Rift...the first paragrpah I more or less got, but the second one? Oi ve.

I'm FAAAAR from a techie.

My apologies if my terminology was off.

I bought a complete tinware set including a new cooler, stand, etc.

I was wondering it would have been a good idea to mount another cooler to the other side - somehow (seeing as how the fan inlet is there), and then connect the two...in case I was unclear.

N.

Post by **Tony Z** » Fri Dec 07, 2007 10:04 pm

a BTU is a British Thermal Unit. The amount of energy needed to change the temp of 1 litre of water by one degree celcius in 1 hour.

Think of it this way MTM. You are pushing air thru the oil cooler. The oil gets cooler by adding heat to the air, which removes heat from the oil. Then you want to push that same air thru another cooler. The air will already be hot. You'll prob find that the second cooler will have a max cooling ability of about 10% of the first cooler. Waste of time.

BTW, you dont want hot air entering the fan, because then the cooling of the engine is less....

Riftvalleyvw · Post by **Riftvalleyvw** » Sat Dec 08, 2007 5:32 am

Yes, Tony is right. If you mount another cooler anyplace in the engine compartment it would just heat the air that is being used to cool the engine.

Gasoline contains about 130,000 BTU of energy. A typical VW motor might be 30% efficient at best. That means that means about 39000 btu's are used to propel the car. The remaining 91,000 BTU's are waste heat and must be removed. (It is not quite this simple but approximatly) The exhaust will remove about 30% of this heat (another 39,000 BTU) and the cooling air and the oil cooler will remove the rest. (52000) Typically the aircooling will remove 80% of this (41,600 BTU) and the oil cooling will remove the rest. 10,400 BTU.

There is not much you can do with the aircooling other than stock without incresasing the amount of power required to turn the fan. But you can flow more oil thru the motor and cool that oil. But the problem in a vw is that to flow more oil, you need to modify the motor so motor oil will flow without increasing the pressure of the oil. You increase the oil pressure you increase the amount of power required to turn the oil pump. That will burn more fuel and cause more heat. Not efficient. The oil relief holes in the case must be opened more to allow more oil to flow. The more oil that flows thru the cooler the cooler your motor will be. Many people install nice 72 and 96 plate oil coolers in a full flow system and add a 30mm oil pump and wonder why the motor overheats.. The main reason is that they did not enlarge the relief holes so more oil could flow. They had the same problem that I described above. The oil pump on a VW is the same as you would find on any small hydraulic system. They are positive displacement pumps. As the pressure increases the power required to drive it increases a lot. You can eaisly use an extra 5 HP to drive the pump if it does not relief properly.I sent you guys a link on preparing your lifters to flow more opil to your heads. An excelent modification to keep your heads cool and your rockers well lubricated. Easy too. You should try it. It is not hard. Really helps a lot on motors with preignition problems.

Post by **Tony Z** » Sat Dec 08, 2007 8:02 am

Where is that link? I missed that one.

Post by **Pine** » Sat Dec 08, 2007 8:23 am

Tony Z wrote:I can see that thinking hurts.... so please dont do it anymore.

The best answer ever!!!

Post by **Tony Z** » Sat Dec 08, 2007 8:34 am

What do I get? Any prizes?

Chris · Post by **Chris** » Sat Dec 08, 2007 10:04 am

Yes,an egg beater,WITH instructions!

Congratulations!

ZeroAxe · Post by **ZeroAxe** » Sat Dec 08, 2007 11:08 am

I would like to see the link for the head-mod too if you dont mind. Thanks!

AirPower · Post by **AirPower** » Sat Dec 08, 2007 10:21 pm

Me too Rift, or is it under a different page?

Riftvalleyvw · Post by **Riftvalleyvw** » Sun Dec 09, 2007 8:14 pm

For some reason I cant find the site right now. But here are the drawings. I have my own autocad drawings but I cant figure out how to post them here.... Right click on these and you can download them into your computer.