ShopTalk Forums | Aircooled VW Tech & Restoration Help

I have a '68 bay microbus with a 1914cc engine with twin 36 IDF carbs and a Turbo style muffler. The engine bay is getting very HOT so I need to get rid of this heat and get more cold air to the carbs and fan.

I've covered the header with exhaust wrap which has helped a little but not enough.


I don't want to alter the appearence of the bus - so don't want to cut a hole in the side of the bus.

I've considered making some holes in the engine lid behind the licence plate and putting a fan at the bottom of the air inlet above the battery.

Has anyone on here done any mods to their bus to get the heat out and more cool air in?

Consider a ram intake setup coming in from the underside. That might work well.

If you've ever had an oil leak on your bus, you'll notice the oil ends up on the back of the bus. Putting holes on the back of the bus to allow more air into the bus will result in drawing in hot air from the engine. This is all because the back of the bus is squared off, and not tapered like a bug.

You can try removing the piece of tin that straddles where the engine and trans meet, but on a bay window, it shouldn't be needed. What head and oil temps are you running right now? The engine bay can be warm, but doesn't necessarily mean you are overheating.....

Do you have all of your tin and engine compartment gasketing in? Ray

I'm assuming all the engine tin seals and heater air hoses are in place . What I found that reduced the engine bay heat was to install a ceramic extractor and muffler. I purchased it hoping it would hold up longer than my previous headers (which it has) and was really surprised how much cooler the engine bay was without all that radiated heat, but it wasn't cheap.
Taking off the front tin would work if you never have to stop,but then it would pull in hot air from below,and I would be afraid of carbon monoxide poisoning when using the heater. Good luck. Tim.

I once saw a bus where someone had cut out the left unused battery tray area (easily welded back in) and fabricated a ducting in sheet steel that took in air from behind the rear wheel.Dont know if it worked well,but looked very cool and appeared to have real possibilities.

The oil temp is usaully just above 80 c (180 f) - I don't have a cylinder head temp guage.

When I went on a trip recently (it was a hot day) I was going up some big hills on the motorway (freeway) and I had to stop because the fuel was evaporating and the engine lost power - I couldn't hold my hand on the valance as it was burning hot.

When I mentioned cutting holes behind the licence plate I was thinking that this would alow some of the heat to escape rather than draw cool air in I was also thinking of fitting a small fan there to draw the air out.


I can't cut away the LH battery tray because I have AIR suspension and the compressor + tank are located there

Re: mharney

Consider a ram intake setup coming in from the underside. That might work well.

could you please explain?

I added a scoop of sorts to my engine a couple of days ago. I removed the front tin, drilled a 2" hole on the right side near the fan and used a spacer that usually goes between the stock muffler box and fan housing hose. Wrapped some bicycle inner tube rubber around it for a seal and hose clamped it on both sides to keep it secure.

I then ran the flex hose down to the torsion tube facing into the wind. I'm going to fab some kind of wider scoop or wider hose to drive in more air if it's possible. It's real stealthy and no one would know it's there unless they poked their head under the bus.

Here's a link to the pic:
http://www.plantnet.com/evrein/scoop.jpg

I'm running a 1904 and need all the air I can get. I like the idea of adding a scoop in the left side battery tray.

Well, sort of the idea with the battery tray, but a scoop under the vehicle that forces air into the engine compartment. It does not have to be where the battery is.

Here To Go I've looked at the pic and understand what you've done. is it possible to remove and put back the front tin without taking the engine out?

This is something I've never done before and don't want to end up with no bus for a week, as my daily driver got a busted radiator yesterday so this is my only transport at the mo + I'm going to a show in it next weekend.

I've managed to pull that tin out without pulling the motor, but what a pain in the arse it was. You have to remove the throttle cable and do some fancy moves to get the tin out of the engine bay. I guess it takes a little less time than pulling the motor, but more of a pain.

Though this wouldn't help with cooling air per se, you could take the air needs of the carbs out of the picture by creating an airbox that ducted air from the inside of the bus into the carbs. Of course that would increase the ambient noise level inside the cabin, but it might help the total situation.

Also, what about putting bilge fans in the channels from the "scoops" on the side of the bus that blow into the compartment. You'd increase your cool air volume then, I would imagine, particularly when you were standing still.

Years ago, someone in SLC routed the intake of thier carb into thier passenger compartment of thier bug. Said it made a night and day difference when it came to his heaters output. Made sense, if you're pushing air in a bottle, you need to pull it out as well.

Off topic, but i've toyed with the idea of routing both heater boxes to the front heater (like my westy was), and instead of heat coming out of the log under the back seat, a bilge blower would suck air out of the interior through that vent, pulling more air through the heater system. Since the air was being drawn toward the back of the bus, all the heat wouldn't stay up front either. It would be warmer up front, but hey, it's our bus, right?

I have a blige blower in the paper hose leading to my front vents. It works great, but a little noisy. But it beats freezing. I read a while back you should put rubber grommets between the fan and the hose, it'll cut the noise a little. I've also seen people split the hose coming out of the later bay engine fan. Then they route a hose off of the split up into the rear of the van. I'm thinking about that one also.


-=Rob
'77 Westy

Vanman,

I started to work on it with the engine in place, but soon realized it was easier to just take the engine out to do it right. Working around the fuel line, Kadrons and doghouse tin wasn't fun, so I pulled it out. Only took 3.5 hours, but I work slow sometimes and I have to disconnect mud flaps and a full flow filter in addition to the usual stuff.

If your engine is mostly stock it shouldn't take you too long.

Speaking of using cabin air, I also pulled out the gas heater tin and propped up my rear seat about a half inch to draw in some extra air. Seems to work ok and the fan noise isn't much louder than when the tin was in place. I'll know the next time I'm on the freeway more than 20 minutes if my dipstick doesn't light up. If it does, it's time to find other ways to get air to the engine.