TheSamba.com :: View topic - Getting hot on the freeway is becoming a little annoying!

Mon Oct 14, 2002 8:45 am

So here's the deal. A couple of months ago I decided to upgrade to a bigger stock engine (1300-1600dp) thinking that 1600 parts are easier to find and I'll get a little more h.p. to boot. I'm beginning to think this was a bad Idea. The performance is better, no complaints there (depending on which carb and distributor I'm using) but it seems like no matter what I do, I keep getting hot on the freeway. There is never a problem in town, even when it's over a 100.

In an effort to cool it down, I've switched to a 34 Pict 3, swapped the distributor with an SVDA and just this weekend, I finally installed a doghouse fan shroud and oil cooler thinking this will really help. Well, It didn't. The only real thing that made any difference was going to the 34mm carb. I was able to travel longer on the freeway before I started getting hot and the maximum temp went from 250 to about 240. I was really surprised that the doghouse didn't do anything.

The only other thing I can think of is that maybe my compression is too high or my timing might be to blame. I don't know what my compression is but my timing is maxing out at about 30-32 BTDC. That puts it at about 7.5-10 degrees BTDC at idle.

Any ideas? I don't want to go with an external oil cooler (at least not yet) when I know that other bus drivers here in Hell's Kitchen (Phoenix AZ) are not overheating.

Mon Oct 14, 2002 8:58 am

other than timing, couple simple things, if the engine is new or newly rebuilt, it will run hot for a while. you probably know about all the engine seals and the deal with checking the belt. if you are running a stock exhaust, you may wanna get something on there that lets the exhaust out a little easier. i wouldn't go to and external oil cooler. and how fast are you driving the bus?

Mon Oct 14, 2002 9:07 am

I know of one trick that helps,look at the size of your fan belt and purchase one that is one size smaller,add more shims between the pulley,and adjust the tension. This will make the top pulley smaller and spin the fan alittle faster and increase the cooling air. The larger bottom pulley does the same thing. I have also read that the cooling flaps help direct the cooling air to where its needed the most as well as warm up the engine faster in Gene Bergs writings. The fanbelt tip works for me in Az. Good luck.

Mon Oct 14, 2002 9:12 am

The doghouse cooler works better than an external oil cooler. If you decide on one get the type with a thermostat that also retains the stock cooler.External oil coolers kill alot of motors from either too hot engine oil or leaks that aren't found until the red light comes on.

Mon Oct 14, 2002 9:29 am

Well, I've really messed with my bus in this area, A couple of things...Do you have a Header? If so, what kinda jet do you have in your Carb? If you do have a free-flowing header on your system, and the same jet, you could be 10-20 degrees hotter...that's a rule of thumb. Another thing is, I have 009, and I know that people say they advanced a good 22-24 degrees? something around, so if we(stock engines) want to be about 29-30 total degrees in advance, we need to keep the timing at about 6 degrees BTDC, so basically a little to the left of the 7.5, that works great for me! One other thing, what kinda gas are you using? Premium? You should try it, and see what you think, if you already aren't, it'll keep the engine cooler, cause when it gets crazy hot in their, it'll ignite it just cause of the temp, not the spark plug.
Check your points, or elctronic points, make sure they are set up right! This is also a REALLY big one!
OK, now a couple years back, I changed to a doghouse style cooler...actually, I just switched the alternator, to a Gen. But one thing I forgot to switch was the FAN! the fans are deffinitly 2 different sizes, cause the bigger one has to feed the cooler in a different location...MAKE SURE YOU HAVE THE RIGHT SIZE FAN! please...learn from my mistakes, cause it's a DUMB one....trust me...so, just double check things, cause even though it sounds dumb, it CAN be overlooked...in a hurry.
Let us know what you figure out, that would be awesome! Peace.

Mon Oct 14, 2002 9:34 am

I know you've been on here reading stuff for awhile so excuse if your already aware of all this....

Do you have all the engine compartment seals ect sealed up good.... spark plug wire boots every little thing?????

Did you get the little piece that fits on the back of the oil cooler with your purchase of the offset parts? the small black "L" shaped thing that keeps the some of the air from escaping before it passes through the cooler?
Did you glue some foam over the oil cooler itself (Like the factory did) to make sure all the air is passing through the cooler fins and not bypassing it... the gap in between the cooler and the fan housing is 3/8 inch on each side and alot of air is blown right by.... Did you get the wide fan too???? all the proper exit tin ect?????
what kind of crank pulley are you running? are you sure about the timing marks???? Some crank pulleys(earlier ones) are smaller diameter by 1/4 inch and it can be hard to discern without measuring of comparing it to a 1600 pulley.... just some of the things I can think of right now...

Mon Oct 14, 2002 10:22 am

A lot of you guys are asking the same questions so I will do my best to answer them all. First, I do have the correct (larger) fan. Second, my doghouse shroud didn't come with the fins attached as they are hard to find. And it is an original VW shroud, not a cheap aftermarket one. The hot air discharge is installed, don't want that heat going right back into the engine! My distributor again is a SVDA from aircooled.net that claims will increase your mileage and make your engine run cooler. I installed pertronix in it too. My pulley is the stock early style and the belt is pretty tight so I don't feel that it is slipping.

The only part of the engine that is new are the heads, pistons and cylinders. They probably have at least 500-800 miles on them now. The valves have been adjusted and all the sparkplugs, cap, rotor and wires are fairly new. I have all the tin except the thermostat fins (hard to find).

And to answer Keifernet's questions, there is no foam anywhere and I'm not sure what the "L" piece is that you are talking about. Could you elaborate please?

Mon Oct 14, 2002 10:27 am

Oh, I forgot to add that I usually don't drive past 60 mph but it will get hoe lower then that.

Mon Oct 14, 2002 10:28 am

Hoe, hot..same damn thing. (fucking fingers!)

Mon Oct 14, 2002 10:48 am

And and and I'm using stock exhaust with heater boxes.

Mon Oct 14, 2002 1:21 pm

I would ensure toyr timing is no more than 32 BTDC @ 3000 rpms. Do NOT set the timing at idle and assume the distributor od advancing things correctly. It only takes a couple degrees to really heat things up.

Next, pull off the fan shroud and glue on a piece of 1/2" foam to the outside of the oil cooler. This is REALLY important!! Air is "lazy". If it's easier for it to go around the cooler, it will. The foam will not allow the air to go around the cooler.

Ensure you have ALL the cooling tin in place and good engine bay seals. Especially ensure you have the the cooler exhaust tin in place.

What was your CR set at when you built the engine?? Good luck!!

Nate
http://www.nateswaterart.com/vw/

Mon Oct 14, 2002 1:31 pm

without the air direction vanes in the shroud, you will run 20-25¦ hotter. that's your problem.

Mon Oct 14, 2002 1:44 pm

Mike, just for info, I run a 1600dp, 34pict3 with a larger jet-148 or so, 094 dist with petronix, stock bus single pipe exhaust, doghouse cooler and shroud with correct fan and no thermostat flaps, and I get to 240-250 degrees on a very long drive (50 miles or more) here in AZ on a pretty darn hot day. Usually it runs around 180-200 on a normal day of driving in the heat around town and small parts of highway. This is on a '60 panel by the way with a '65 big nut transaxle, at about 62-65 mph I run about 3500 rpm's and usually at 220 degress average at that speed and rpm. FYI.

Mon Oct 14, 2002 1:52 pm

The foam piece sounds like a good idea and I will definitely add that on. I wonder if my local BAP has them?

Again, I don't know what my CR is because I don't have the tool to measure it. When I bought the pistons, you could only by flat headed ones, not the dished topped ones that VW used on their bus engines.

Even when it's cold outside, I will start to get hot after driving 60 mph for about 5-7 miles. My main jet is a 127.5 and my idle jet is a 155 (or 55, I can't remember how they go).

Mon Oct 14, 2002 3:40 pm

Mike, it does not have to be any special foam... bought at a parts house... you can probably get a scrap at a upholstry shop or at a fabric store/ hobby craft place....

I have some of the thermostatic flaps if you need some....

When you put the cylinders on did you use any shims??? You probably should have done so to lower the compression... are the heads NEW or Rebuilt???? rebuilt heads have often been "surface flycut" and this will raise the compression... also most orig cases have been "decked" when rebuilt at some point, removing more metal and raising compression further... that's why you need the cylinder spacers... at least .030 and more like .060 is what I have found is needed for stock engines ( as a general rule of thumb after measuring deck height on a bunch of rebuilds)

Did you put the "air deflectors" on under the cylinders?????

Go to www.type2.com in the library under the "oil coolers" section is some pics ect. of the piece I was reffering to.... by Bob Hoover... shows the original and how to make one if your is missing and you can't find one...( I have a few of those laying about too...)

Measure your pulley against a stock or aluminum one for a 1600... if it is smaller like I said it may be... buy a alum degree wheel or get a stock 1600 one somewhere.... the fan will turn faster....

sounds like everyone is chiming in with alot of good advise... you ought to get the temps down

Mon Oct 14, 2002 4:51 pm

Thanks for all your help fellas and I will do my best to heed to your advise.

Mon Oct 14, 2002 7:25 pm

They sell a glue backed foam to seal doors at hardware stores and lumber stores and its on rolls and it comes in different widths and looks almost identical to the original and is super easy to install. and......

Mon Oct 14, 2002 8:18 pm

OH NO! they got Timmy..... damn aliens! they must think he knows who the name theif is! either that or he fogot to pay the bills! LOL!

Mon Oct 14, 2002 9:07 pm

when you say "side of the oil cooler" i'm guessing the side that is closest to the outside of the engine tin? (closest to the tire?

Tue Oct 15, 2002 7:11 am

Earlyman,I'm not sure what your referring too... I would say the sides of the cooler in the refference to the foam means the solid sides between the fan housing...
Several of the manuals I have show a factory pic with the foam in place.... one is an old Clymer and the other the Bentley...looks like the same factory autorized picture... I'm pretty sure it was an offset oil cooler thing only.... noe faom and that little "L bracket missing makes a huge temp difference in warm climates.....