External oil cooler

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rlepecha

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Hi,

Been recently looking into replacing the doghouse oil cooler with an adaptor plate to hose in a oil filter and then into a separate oil cooler with fan.
My calculations work out that a 13 row x 235mm Mocal cooler would result in efficient oil cooling with something within the similar range of pressure drop to stock across the cooler (to maintain the use of the dual relief ports in the case) when using a 30mm oils pump.
It makes sense to me given the original cooler is 7 row (I think) and about the same height. Obviously I presume the Mocal cooler would be more efficient.

Then I look at the available coolers with fans from the usual suspects, they are huge 70+ row coolers and must be way too large, therefore resulting in oil temps barely rising above 80 degrees if using a wax stat to control flow to the cooler, but they're also pretty difficult to place easily.

I've found 1 post on the SSVC forum where a bloke is running a 16 row Mocal with no fan and just a scoop, he could drive at 70mph and the oil temp wouldn't go over 100 degrees. So a 13 row and a fan should result in lower temperatures.
That's only 1 person though, everyone else appears to be using the massive bugpack and similar coolers.
I basically need some clarification and any bodies experience of external coolers to ensure I purchase the correct one.


Thanks in advance.
 

Resto-raider

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In my opinion just fit the biggest oilcooler possible and put a thermostat in line.
That way you're always running the optimum temperature. That's what I did on my 1776cc. Works perfect.
 

Alex VW Heritage

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Resto-raider said:
In my opinion just fit the biggest oilcooler possible and put a thermostat in line.
That way you're always running the optimum temperature. That's what I did on my 1776cc. Works perfect.

presumably that was on top of your standard factory oil cooler in the fan shroud?

Which is exactly the way I'd go too.

Sounds like the thread starter is after removing the factory cooler?

The only reason to do this in my opinion is if your running porsche style cooling and have no room in the shroud for the stock cooler.
 

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Alex VW Heritage said:
Resto-raider said:
In my opinion just fit the biggest oilcooler possible and put a thermostat in line.
That way you're always running the optimum temperature. That's what I did on my 1776cc. Works perfect.

presumably that was on top of your standard factory oil cooler in the fan shroud?

Which is exactly the way I'd go too.

Sounds like the thread starter is after removing the factory cooler?

The only reason to do this in my opinion is if your running porsche style cooling and have no room in the shroud for the stock cooler.

Not a fan of Porsche cooling.
 

gagvanman

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I added an external oil cooler and remote oil filter to my 1776. Got a thermostat to fit for the cooler months though.
 

rlepecha

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Thanks for the replies.

I was under the impression that modern remote oil coolers and fans would be more efficient than stock hence my idea to fit a remote cooler in place of the stock cooler. It is now apparent that the original cooler is actually going to be the most efficient (read Gene Bergs tech on oil coolers).

I was hoping to replace the stock cooler to allow me to drive at higher speeds for longer periods of time. Currently I can't cruise at 55 mph for more than an hour without the oil reaching 120+ degrees, that's measured using a calibrated thermocouple in a dipstick size tube.
I understand that this is most likely down to an issue with my current stock oil cooler or engine, I dont want to have the same problem with the one I am building up currently.

Current specs are twin Weber 34icts, 1641cc. That's the only changes from stock. My new engine will be a stock 1600 with just twin carbs for reliability and hopefully no cooling issues!
 

Bay-low71

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I'm in agreement with Alex, I run my standard cooler then plumbed in an external filter outlet goes to a wax stat (Mocal) if closed routes back to the case. If open sends oil to a external fan assisted DeRale oil cooler stat for fan switch is placed on the inlet, then routes through cooler back to the wax stat to the case.
I will agree I think this is overkill and didn't notice the fan switched on at all (so far).
I think the importance is the use of thermostats as you don't want to overcool, conversely you want addition cooling when temps get above the optimum level.
or the record I used Think Automotive, bought my cooler from Summit Racing in the USA which worked out cheaper. Cool air can now provide good cooler options. Good luck with it ;)


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Bay-low71

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Just a quick note the wax stat doesn't fully close it just provides a less restrictive route for the oil when temps are below that of the operating temp of the stat... Ben


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rlepecha

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I am now planning to fit one of the CB Performance maxi 3 oil pumps with the in and out on the pump plate. I've read some issues regarding pressure drop through the fittings but I've done some calculations and I get less than 0.5 psi drop across 2 1/4 NPT barbs. There's going to be more pressure drop through the external filter than that!
 

Alex VW Heritage

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rlepecha said:
I am now planning to fit one of the CB Performance maxi 3 oil pumps with the in and out on the pump plate. I've read some issues regarding pressure drop through the fittings but I've done some calculations and I get less than 0.5 psi drop across 2 1/4 NPT barbs. There's going to be more pressure drop through the external filter than that!

Great option, you will need to modify the engine brace bar to clearance the fittings, just to give you the heads up.
 

jonboylaw

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I'd clean out the doghouse cooler and ensure that air can flow freely through it and it is sealed with foam strip to stop the cooling air blowing around the sides first. Plus make sure the "Hoover" bit is in place. I doubt a 1641 will be generating loads if extra heat to warrant an additional cooler.
Strip the old one out. Wash through with white spirit ( fill and leave over night then wash through and leave to dry a few days) blow through the matrix with compressed air etc.


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rlepecha

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Alex VW Heritage said:
rlepecha said:
I am now planning to fit one of the CB Performance maxi 3 oil pumps with the in and out on the pump plate. I've read some issues regarding pressure drop through the fittings but I've done some calculations and I get less than 0.5 psi drop across 2 1/4 NPT barbs. There's going to be more pressure drop through the external filter than that!

Great option, you will need to modify the engine brace bar to clearance the fittings, just to give you the heads up.
Thanks Alex, I had already seen a couple of undecided posts about whether it would fit or not. I presumed I would need to clearance the bar.
jonboylaw said:
I'd clean out the doghouse cooler and ensure that air can flow freely through it and it is sealed with foam strip to stop the cooling air blowing around the sides first. Plus make sure the "Hoover" bit is in place. I doubt a 1641 will be generating loads if extra heat to warrant an additional cooler.
Strip the old one out. Wash through with white spirit ( fill and leave over night then wash through and leave to dry a few days) blow through the matrix with compressed air etc.


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I've ordered a new oil cooler for the new engine so I can be sure of no blockages.
 

starbiscuit

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How did it go with the CB Maxi 3 pump?
How much "clearancing" did you need to do?
Do you have any pics?
 

rlepecha

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starbiscuit said:
How did it go with the CB Maxi 3 pump?
How much "clearancing" did you need to do?
Do you have any pics?
Not managed to get it finished yet. Had a busy few months doing everything but sorting out this engine..
 

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