another stupid question

[Guest Combiwagen1969]

Now this will seem like another stupid question but what are these pipes called and what do they do? As far as I can work out they take hot air from the exhaust/exchangers and put it back through the fan so are they there to speed up the engines warming up?

 

If so can I take them away (when putting in a karmenpesa exhaust)?

[Guest Raggare]

they are called fresh air hoses, and they blow air from fan shroud to heat exchangers and further on to the cabin. if you plan to use heat exchangers with your new exhaust header, you can buy longer hoses so you can clamp them to the heat exchangers. or if you use j-tubes instead of exchangers, plug* those airlets on fan shroud and put some sheet metal on holes on that engine tin over exhaust so that hot air cannot rise to the engine compartment.

 

(*research says that the best cooling is achieved when they are not plugged fully, there should be some 'leak' so that original desing of fan shroud is in it's best use, for example vw thing doesn't have those snorkels in it's fan shroud and the inside of it is different also vs. type1/2)

[Guest Combiwagen1969]

Of course! I was thinking backwards. they blow the air into the exchangers and forward to heat the cabin - not the other way round. I like the idea of lengthening the pipes - although it may be a tight fit. I'd go the J Pipe route but I don't like the idea of having no heater - at least to de-mist the windscreen..

 

during the overhaul I was going to slip in the 1641 pistons but the bible tells me not to (The 'How to Keep Your Volkswagen Alive' bible that is). do you know what other changes I should make to 'balance' the engine if I do put in the larger pistons??

[Guest Raggare]

i wouldn't recommend slip-ins too, sure they are easy to just slip-in as they are called, but they are machined from 85.5mm 1600 cylinders thus making a cylinder wall thickness thinner. now a bus is a big heavy thing which needs a bit more from it's engine, also producing sometimes more heat, well gearing is also short to compensate hp needed to get that box moving.. but anyway heat is enemy of the engine, and it can warp thin cylinders and increase blow by of pistons and rings. and they don't increase engine size that big, 1584cc vs 1641. i would recommend either stock 1600 p&c's or 90.5mm which are almost as thick as stock 85.5's, but since their outside diameter is larger, engine case and heads needs some machining.

there is a old rule, cheap-reliable-fast, you can choose two of them ;D

[Guest Combiwagen1969]

Ok, so if I stick to standard pistons is there any way I can get a bit more power from the engine? I am not interested in top speed but as you said, the bus is a big heavy thing and it needs more 'oompf' to get up the hills without having to change down the gears and have a queue of traffic behind.

 

So is there anything I can do without spending huge amounts of cash, getting a bit more power and keeping the engine within operating temperatures?

[Guest Raggare]

cam designed to make torque, 'low' lift and long duration if i understand it correctly, maybe some dual 1 barrel carbs like kadrons, more freely breathing exhaust, should pep a bit your engine. put few k€'s and you'll have a stroker :)

[Guest Combiwagen1969]

so where would I get such a cam? are they available 'off the shelf' or where would I be able to get one done?

 

Same question for the carbs. Do you know where I could get my hands on these?

 

don't understand your last sentence -put few k€'s and you'll have a stroker :)-

 

As for the exhaust, isn't this the idea with the snakes-nest design, +Equal back pressure to all the cylinders.

 

I appreciate you answering these questions.

 

engine is on a bench in my shed and I've cleaned it up a bit, set the valves, a few new gaskets and 'o' ring on the distributor, that kind of thing. I put new stock pistons in about 18months ago. looking for an original air filter -the oil kind- to replace the little filter thats on there now. got the fan housing ready for a re-spray. The heat exchangers are not great but I may get away with welding them a bit. The engine has obviously been running too rich but I will have to wait till I get it slotted back in, timed and run about a while before I can address that.

 

One interesting point. The 'How to keep your vw alive book' says the groove on the rim of the distributor that lines up with TDC should point towards the back of the engine (back of the van). Mine points the other way, towards the front.

[Guest Raggare]

i guess all parts are available off the shelf in all finnish vw parts suppliers.

keiteleen kone is one place where you can find those kadrons about 300e a set.

building a stroker is 'a endless well'. you need to replace almost everthing in your motor, but then it makes some good torque for a bus.

[Guest]

Go to www.shoptalkforums.com for TONS of discussion in english.

 

A very nice all-purpose bus engine would be 1776cc with an engle W110 cam, 8:1 compression ratio, and dual Kadrons. Easy to build and tune, and lasts forever. That would let you keep your old crank, you could use your old con rods if they check out. The case and heads need to be machined larger to accept 90.5mm cylinders. Good opportunity to add full-flow oil filtration, when the case is apart. Of course, no mods are recommended without a full rebuild anyway... possible line boring of the case and at least new bearings.

 

Jan