TheSamba.com :: View topic - Where and how to mount an external oil cooler on a Bus

Sun Apr 10, 2005 8:40 am

thinking of adding a mesa cooler w/ fan and 180 degree in line thermostat. my question is where is the best location to mount this. anybody?

Sun Apr 10, 2005 9:22 am

Somewhere between the crossmembers under the bottom.. Plenty of fresh air there.

Sun Apr 10, 2005 10:11 am

Wherever you mount it, make sure your plumbing is in good shape and of high quality. Something that can take high heat and high pressure.

Sun Apr 10, 2005 10:29 am

Hi lenwood,
Best in our opinion to avoid an external cooler. The lines themselfs are just another part to go bad and blow an engine. Plus while the external cooler might keep cool the oil, while the heads will overheat and drop valve seats.
We take doghouse shrouds and widen them to install a type 4 cooler for 40% more interior/exterior cooling surface. A "D" stock lower pulley, a 356 Porsche generator pulley up the fan RPMs for not only more cooling air through the oil cooler, but through the heads. Also clean out ALL the casting flash from the heads and install a 35 mm wide cooling fan (inside measurement). We keep the engine RPMs down with a freeway flier tranny. If anyone wants we will happily send them our "Modified Tranny History" about how we went to a FF tranny.
Eric&Barb

Sun Apr 10, 2005 10:42 am

where to mount: on your baja

Sun Apr 10, 2005 11:20 am

Don`t listen to them. Mount it undre your bus. Run hard lines with AN fittings back to the motor. Than run braided line to the motor. A GOOD
quality cooler and fan will reduce your oil temp greatly. However, if you are running a stock motor then there is no need for it.

Sun Apr 10, 2005 3:46 pm

Here's where I put all mine...

Best to use hard lines where possible and AN fittings on anything you want to remove easily, like at the case, filter, etc...

Sun Apr 10, 2005 5:22 pm

WideFive wrote: Here's where I put all mine...

Best to use hard lines where possible and AN fittings on anything you want to remove easily, like at the case, filter, etc...

Good place, I've also mounted the Mesa style w/o fan in front of the torsion tube, custom box using steel braided teflon lines. Works great.

I'm also an advocate of the Type IV doghouse conversion as well.

Mon Apr 11, 2005 12:07 am

Ah the old cooler debate, I side with eric and barb, if your engine is running hot then fixing it with and oil cooler is not going to fix the ACTUAL problem. :cry:
You have not told us what engine you running in what bus either.

Mon Apr 11, 2005 7:40 am

krusher wrote: Ah the old cooler debate, I side with eric and barb, if your engine is running hot then fixing it with and oil cooler is not going to fix the ACTUAL problem. :cry:
You have not told us what engine you running in what bus either.

I don't recall him asking if it was a good thing to do.. A thermostatically controlled system is excellent but don't forget a filter. I know, yeah VW made it, it's gold, leave it alone bla bla. Yes an overheating engine is a bad thing, all tin must be in place, agreed. Considering Berlin is at a higher latitude than Winnipeg, a filter and a cooler are not a bad thing if done properly especially if you're in a daily driver in Dallas, in the Summer.

Mon Apr 11, 2005 8:07 am

can you route your oil lines through the heads to help cool the heads?

Mon Apr 11, 2005 8:13 am

good question lind. i know that cant be done, i'm running a 1776 w/dual kad's,mild cam,type3 trans. at 70 mph she runs 220-230 temp. i know buses arent meant to go that fast. around town and traffic,200-210. i just want some insurance when on long drives. slow down huh?

Mon Apr 11, 2005 8:31 am

lenwood wrote: good question lind. i know that cant be done, i'm running a 1776 w/dual kad's,mild cam,type3 trans. at 70 mph she runs 220-230 temp. i know buses arent meant to go that fast. around town and traffic,200-210. i just want some insurance when on long drives. slow down huh?
the heat is coming from several different directions. the horsepower that you need to go over 55mph rises sharply, so when you are going over 55mph, you need a lot of hp in a hurry. the air flow patterns make it harder to get air into your engine compartment the faster you go. then, the engine vents are only designed to flow so much air, so when you put a firebreathing engine with a doghouse fan into the bus, it may not be able to flow all the air that it needs at high RPMs. and of course performance engines run hotter generally.

so do you want to put a lot of effort and money into modifying the engine and body to make it run cooler, or do you want to drive slower, or just deal with the 230 degree temps.

Mon Apr 11, 2005 8:51 am

lenwood wrote: good question lind. i know that cant be done, i'm running a 1776 w/dual kad's,mild cam,type3 trans. at 70 mph she runs 220-230 temp. i know buses arent meant to go that fast. around town and traffic,200-210. i just want some insurance when on long drives. slow down huh?

One of the biggest contributors to high temps is high compression ratio, balancing the performance/power vs lower operating temps. DO you know what your compression ratio is? Also do you have all of the OG tin, including the shutters installed? Also is this a doghouse configuration or inline oil cooler?

Mon Apr 11, 2005 10:26 am

theeffort needed goes up in proportion to the square of the speed

Where do you get the stuff about air flow, Lind? please share

If you add ugly scoops over your vents (you can make them detachable, drill no holes) you will drop Head temps significantly, which is more important than oil temps, actually., and oil temp drop would follow from head temp drop.
the air scoops drop temps by blasting air through the engine compartment and dropping the temp of air in the engine compartment, which tends to be warmer than ambient outside temps. then the actual cooling air is then cooler than w/o scoops.

also, I got good oil temp drops from cleaning the casting flashing a la Eric& Barb, and switching to a typeIV doghouse. I don't have a head temp sensor on that, so don't know, but the oil temps dropped ~5 to 10* Celcius on the freeway. I did this about 5-6 years ago to the engine that is now in my 61, which has had a good # of miles/road trips on since.

what are your rpms at 70mph?

Lind wrote: lenwood wrote: good question lind. i know that cant be done, i'm running a 1776 w/dual kad's,mild cam,type3 trans. at 70 mph she runs 220-230 temp. i know buses arent meant to go that fast. around town and traffic,200-210. i just want some insurance when on long drives. slow down huh?
the heat is coming from several different directions. the horsepower that you need to go over 55mph rises sharply, so when you are going over 55mph, you need a lot of hp in a hurry. the air flow patterns make it harder to get air into your engine compartment the faster you go. then, the engine vents are only designed to flow so much air, so when you put a firebreathing engine with a doghouse fan into the bus, it may not be able to flow all the air that it needs at high RPMs. and of course performance engines run hotter generally.

so do you want to put a lot of effort and money into modifying the engine and body to make it run cooler, or do you want to drive slower, or just deal with the 230 degree temps.

Mon Apr 11, 2005 11:52 am

well,the motor i have is low comp 8.5:1 brand new everything.doghouse cooler,new tin,heater boxes etc. rpms not sure.no tach.cooling scoops? good idea? for summer maybe? i run good oil,20/50w gtx. type 4 cooler? future mod maybe?claras idea might be a quick fix for summer just to be safe. bigger fan smaller generator pulley? spin the fan faster? thanks everybody for chiming in. inc you lindo.....

Mon Apr 11, 2005 12:14 pm

I have heard of instances where changing the fan speed can cause a vaccum effect, the fan is moving faster but less air flow. Has anyone else ever heard of this?

Reading this thread makes me appricate driving 65 mph with my 1500sp.

Mon Apr 11, 2005 12:22 pm

lenwood wrote: well,the motor i have is low comp 8.5:1 brand new everything.doghouse cooler,new tin,heater boxes etc. rpms not sure.no tach.cooling scoops? good idea? for summer maybe? i run good oil,20/50w gtx. type 4 cooler? future mod maybe?claras idea might be a quick fix for summer just to be safe. bigger fan smaller generator pulley? spin the fan faster? thanks everybody for chiming in. inc you lindo.....

One of the tricks I've heard of, seen, but never tried is using the 356 style pulley on the generator. The Type IV cooler requires some tin work and Gene Berg sells the kit. Larger Hoover bit etc.

Mon Apr 11, 2005 3:38 pm

I wanted to stay out of this one because I could see it turning into a pissing match...

Lenwood,

Your engine is fine. Just make sure there are no gaps in the tin and the thermostat is hooked up. The flaps direct air to the heads and cylinders depending on what posistion they are in, so they are very important to have intact and functional.

You might also try switching to 10W30 or 15W40 oil. 20W50 tends to hold heat longer than 10W30 because it is so thick. It doesn't flow as well so it makes it harder to absorb oil from hot engine parts (doesn't soak in as well). I use Valvoline 10W30 because it is very clean oil and cheap. If the engine is extremely worn, I might use 20W50 in a pinch only during summer....just because it fills in the gaps on worn bearings better.

The ideas Clara is talking about are spot on. The air scoops will probably make the biggest difference overall and they are easy to fit. IF you STILL need an external oil cooler during really hot summer, then you could do what you're talking about....but save your money for now. Scoops are cheap, and I have a set I'm selling soon.

Oil temps are caused by long hauls at high RPM or just constant loading for a long time.
Head temps are caused by sudden load changes (such as going up a short steep hill) or lugging the engine. A long steep hill is amost certain death to a VW engine if you hold it in 4th gear. The PNW is notorious for killing VW's over the mountain passes.

The 356 generator pulley is a common mod. It increases the fan speed by I think 6%.

Mon Apr 11, 2005 6:22 pm

i have played with the idea of ducting extra air through the front tin. has anyone tried this?