thanks again everyone for the previous info ,but i am back again,from what i can find out i have a 65/66 type 1 with a 1300 motor.what my question is after looking at the motor i have noticed that on either side of the engine are two metal ducts (pipe looking things) that have what i can best describe as something that looks like caps slide up over them and held on with hose clamps are they supposed to be blocked of as some motors i have seen have rubber hoses running from them to some sort of hole in the engine floor going to something ????
i am just concerned about over heating but by the looks of it they have been like this for years???? any ideas?

If your car has extractors fitted you lose the two tubes that run down to the standard exhaust,so then most people block the two outlets with caps and hose witch is your heater cheers shane.

without explaining, all is fine. (there will be no probs with overheating!)

If you want to have a heater and you have heater boxes on your exhaust pipes, connect the outlets on the cooling fan shroud to the heater boxes with corrugated paper/aluminium tubes. If you don't want to have a heater, block off the outlets as if they are left open then air which could cool the engine will go out of them to waste. In winter that would'nt matter. In summer it could matter.

jake raby did some testing a few years ago and found out its just as bad to cap them off as it is the leave them open
capping them off interupted the flow in the fan housing which lead to head temps going up

the correct thing to do was cap them off but put a hole in the plug about 1" which simulated the same restriction as a heater box

the actual results are on paper on his website so no im not pulling that out of my arse

-Joel

Joel, if you have the heaters all connected and working and you have them turned off no air would be running past the heat exchangers because they would be blocked at the flaps. But as you should only be using your heaters when it's cold (duh!) the loss of cold air would possibly be made up as the air cooling the engine would that much cooler than during summer. Look this makes sense to me honestly. Bollocks I've just read Shaihuluds post and he put it better than me

nah if u have a close look at the heater boxes they have a by pass valve thing at the back

when the main flap shuts it pumps the air out these
otherwise the heaterboxes would turn into giant ovens and nuke the heads

not trying to be a smart arse but my old boss at the garage was head of the service department of lismore dealership and explained all this to me

plus the original thermostat flaps was what regulated air flow when cold

if anyone has heaterboxes on there car dont remove the hoses

the heaterboxes need air pumped thro them when not in use otherwise they well get really hot and start to overheat the heads

if u have fumes coming into ur cabin instead of removing the fan housing hoses just remove the hoses that go from the heaterboxes to the heaterchannels either side of the gearbox instead

Well, in the words of Stan Marsh, "I've learned something today!"

Well
I've Never read anything like that before either...
but I have seen the small hole in heater boxes that allow air to flow thru them all the time...
So, I've learnt something New too...

I would have said to keep the vents blocked off...

I run heater boxes

but If I didn't, like Many Many VW owners

I would use the 50mm Welch plugs to block the holes up

as I don't like any air leaks....

Lee

I say block the suckers !!!! Always have and always will.....and never had a problem...

i just had a look its a 1.5" hole in the plugs for optimal airflow

quote from jake rabys site:

the air was to be metered by the heater boxes and the shroud was designed with this amount of bleed and back pressure in mind. I found that a freeze plug with a 1.5" hole in the center provided effectively about the same results as with heaterboxes installed, pressure wise within the shroud....

Remember that even when the heat is off, the air escapes from the heaterboxes through the tiny bleeders on top of them, there is always air escaping from those "snorkels" on the stock shroud, with the original design.

The same rule has applied to the TIV engine with the heater boxes removed- blocking the outlets in the stock shroud certainly has negative results- mine have been open on the Bus for 5 years. Blocking them off quickly elevates temperature differences and really heats up the #1 cylinder...
_________________
Jake Raby

HeHe...block them off and run a power pulley

yeah lol
i only beleive in it cos ive seen test results
but ive also seen a cut open fan shroud and the 2 heater outlets are at the dead end of outer ducting so the air doesnt continue past them to the fins so i cant see it disturbing the flow as much as suggested
and yes whilst i did bring up the holes in the plugs im currently running 1 7/8 welsh plugs in mine with none only cos im to lazy to put holes thro them
i dont have a CHT gauge but ive noticed no real diffence yet

but yea i can certainly see how running the heaterboxes with no air flow thro them would heat up the heads
specially the older ones with the alloy fins inside

-Joel

I suppose if you have heaters why not use them as VW intended. My cab has heaters and has all the parts intact- even the thermostat. The buggy on the other hand has never had heat exchangers fitted and so the outlets have never been left open, I've always believed the more cooling air the better and now nearly twenty years down the track the buggy has never overheated!!

I have a CHT........................block them off