Heating and tin parts identification please.

i knew i shoulnt of looked under neath looks like my bottom tins are missing :-[

 

Have you found any bottom tins yet rik
No one seems to sell them do they

 

Zed says hardly any vans have the very bottom tins, he says if the thermostat isn't fitted it makes no odds, with j-tubes there is no way of fastening it to the tube like it does to the exchanger.....i'm not fussed about them bits for now, i thought about making some out of chequer plate just to protect the push rod tubes.

 

yeah i know, Zed has posted me the important tin that is missing around my pistons, he says more than half the vans he sees have no botton tin so i trust him i'll worry about the bottom tin last, he sent me a picture of it and it looks pretty flat and easy to make.

 

so this other tin thats missing if you look up from where the btm tin should be you can see it between the cylinders yes ?
i tried go get a photo but its hard to with out getting its ass up i the air

 

bare with me whilst I get this right. I'm typing this and then going back and making modifications as I add the pictures

Here is the fan casing front.



Here is how the air to the rear of the engine is channeled down around the cylinder heads on the left hand side (you're looking at the rear of the engine which sits towards the front of the van.



The lower 'under pushrod tubes spanned between heat exchangers and engine which are like rocking horse poo' tins attach to the rear part of this tin. This ensures that the air is directed to the rear of the vehicle

Here is how it looks on the right hand side of the engine



You can also see the 'heat riser' tube. This takes some of the warm and feeds into here



This connects to the air filter intake box and behaves as a warm air intake which prevents the carbs from icing and helps the engine warm up quicker

So now, if you look here this is the upper over cylinder tinware as it is fitted to the engine on the left hand side as you face the front of the fan casing.



Directly beneath this side is your oil cooler, look here for how the engine looks without all of its tinware



So now, what you can see on the left of the engine is the oil cooler, on top of this you can see a piece of tinware. There is also a piece which fits to the opposite side on the other cylinder bank. As you can see, whilst it has a gaping hole in it which channels the air onto the cooler, it is also shrink wrapped around the cylinders, as it also channels air onto them. This is what the one on the other side does.

As you can see in the picture below, this is how the over oil cooler tin interfaces with the upper over cylinder tinware



and this is how the aforementioned piece sits on the other side



and this is how they look when they are together - so imagine these sat either side with cylinders beneath them and the engine block sat between them.



Now, imagine them with the front fan casing on them all bolted up on the engine, you can start to get the picture of how, when the fan is spinning, its sucking air in through the fan, into this casing, and its getting blasted out of the back of the fan casing, out of these rectangular holes left and right



which are attached to these tins



which are shrink wrapped around and interfacing with all of the other tins on the engine.

So now, when you look here under the engine you see push rod tubes

600 src="http://i747.photobucket.com/albums/xx112/rekojoker/Building%20my%20Type%204%20injun/P1080253.jpg" />

above these pushrod tubes and screwed to the bottom of the cylinders you can see a piece of tin. This stops the air from just getting blasted straight out of the bottom, and makes sure it gets blown through the fins on the cylinders and the heads. Without this you will have a cooler top side of the cylinder and a hot bottom side. This will lead to the cylinders warping and the heads will overheat

Here is how they look when they're not fitted. See they are a different shape for either side





So now, on the right side of the engine is where the thermostat is mounted.



the thermostat is the thing which looks like bellow. This is closed. Can you see the cable coming off it, going around the wheel and then upwards? Well, this cable goes up, guided through the tinware and comes out here



this is on the right hand side of the engine.

Now, compare these 2 pictures (i've just learnt that either my thermostat or cable have failed!!)

This picture shows the thermostat open position. This is the position the thermostat opens the flaps too when it heats up. This is also the failed position, so should the thermostat or cable fail the flaps behave as if the thermostat has heated up



this picture shows that same piece, but I have depressed it with my finger. This is the thermostat closed position - therefore, this is the position its in when the engine is cold. Notice how it is spring loaded. I'm pushing against this piece, therefore against the spring.



So now the voodoo fun bit.

Here is the picture lifted off the samba. Sorry its smaller



What can you see is the flaps inside the fan casing. Remember that you are looking at the rear of the fan casing, so the flap you can see on the left of the picture sits in the right hand 'upper over cylinder tinware' and the flap you see to the right sits over the 'top of the oil cooler tinware'

This is in the 'engine hot' or open position. So, see how it works? The flap you see to the left of the picture, see how its attached to the control bar, so attaching it by the bar to the flap on the other side of the engine? No imagine, standing facing the front of the engine and doing what i'm doing in this picture



As i'm pushing down on this bar, I'm replicating what the closed thermostat will do, via the cable. I'm effectively pulling this flap (the one you see to the left of the below picture) down. This will close partially close off the big rectangular hole in the fan casing



The opposite action to this, is that the flap you see to your right, is lifted off the oil cooler.

As the engine warms up, the thermostat expands, the cable moves, the flap you see to your left slowly opens, the one to the right slowly lowers, thus ensuring that some of that nice cooling air is channelled onto the oil cooler, the rest to the cylinders

They were a clever bunch at VW, over engineering to compensate for the fact that rear engined aircooled is a pretty crap choice for a vehicle.

Hopefully this will help you understand how these engines are cooled, and that each individual piece of tin, and how it interacts with the piece next to it and other essential items, like the thermostat, is absolutely essential to not only keeping your engine cool, but also ensuring that it operates at its most optimum and efficient state.

Don't be fooled though, too much cooling is just as bad as not enough - over cooling will prevent the engine from getting up to its correct operating temperature properly, especially in our UK climate, and will massively increase engine wear and massively decrease engine longevity.

I haven't covered the elusive 'under pushrod tubes spanned between heat exchangers and engine which are like rocking horse poo' tins, I don't have any images to show you. But imagine these channelling the spent air, which is now warm having served its purpose, being spat back out towards the rear of the vehicle. The one to the right of the engine as an essential tin for warm up, not critical, but if you have them you should keep them in good nick. This ensures that the thermostat warms up and opens at the correct time as the engine warms up - it will open marginally quicker with this 'under pushrod tubes spanned between heat exchangers and engine which are like rocking horse poo' tin in place

 

if you mean on my van there is tin missint that basically joins the sump to the heat exchangers just like flat tin, but then above the push rods and covering the piston pots mine is missing too, basically, is yoyr westy a type 4 engine? there are pictures in either this thread or the main thread on my van.

 

http://i747.photobucket.com/albums/xx112/rekojoker/Building%20my%20Type%204%20injun/P1080302.jpg/img]
i think there the tins i ve got
i know I've not got a thermostat [glow=red,2,300][b][glow=red,2,300][b]FACT[/b][/glow][/b][/glow]
so theres no tins to fit below the pushrods then ?

 

i'll be cracking on with another new engine build in about one months time, when I do i'll be documenting, photographing and videoing every step. For my own piece of mind, so I can show the new owner what i've done, but also to share the knowledge

 

Joker K+ absolutely spot on explanation on how it all works.

Mine was a mess when I bought it, but now the cooling is exactly as VW intended, including the rubber bellows supplying the alternator.

Re the Thermostat I agree, VW fitted it, so it should be fitted. Most car makers don't fit unnecessary parts just for fun

 

Most excellent write up of the cooling Joker. That must have taken all day! I vote it gets added to the How toos.
I'd like qualify the advice I've given Rick by saying I know he's skint, *******ed off and wants to be able to drive his bus withour totalling the engine. So I've concentrated on the most serious stuff, and in an order where he can come back and do more when the miserable git cheers up.
I've sent him the most important tins free and gratis. As Joker says, the lower ones are for a rainy day - they do turn up but not often. Also the thermostat. Firstly it won't work correctly without the bottom tins. Second, again you can't get them. You can make a 1600 one fit IF you have a bust T4 one to canibalise, but still need the bracket etc and the flaps! The thermostat is eay retro fit. The flaps are not.

So I've focussed my advice on getting the cylinder tins and flaps in place. Both these jobs need a bit of dismantling to fit them. Both are imperative to stop rapid engine damage and failure. Once done all the rest is adding bits as he finds them to "fine tune" the cooling system.

Clearly, as Joker describes, It's best to have the lot in place and I'd be looking for the other pieces, BUT the engine won't blow up without them, so Rick can afford to play a longer game and save some panick-buying pennies.

One more thing - Don't fit a silly filter on your oil breather like some people do - your shiny engine bay will be covered in a mist of oil before you know it.

 

wow, it's complex stuff innit? clever stuff but way over my head lol.