fresh air hose exiting tinware question

[kevlar]

I have no heat exchangers , Told I have J tubes instead, so where the 2 inch diamiter flexible steel hoses from fan exit the bottom of the tinware they are just cut off, Would they be drawing in hot air from around the exhaust and is there a special way of addressing the ends of these without going back to heat exchangers? Van is going in for a service and tune ready for france trip and need it to be running right, Kev

 

[who?1]

This should not cause a problem, are you running with standard carb and air filter?

The air pipe also picks up through the tin wear.

 

[kevlar]

No twin carbs , not sure re filter, Kev

 

[Trikky2]

I assume from your reference to heat exchangers that you mean the two pipes that come from the fan shroud and go down through the tinware.

It would be wise to block them off since they will bleed cooling air away from the engine where its needed.

If you remove the tubes and block off on the fan shroud then you should also block off the holes in the tinware, to stop the fan from pulling hot air through there.

 

[kevlar]

just had a look they are twin solex carbs with the large perforated filters on top, Forgive my ignorence I am fairly new to aircooled engines but where is the cool air drawn in from? I think I need a lesson on how the system works, Kev

 

[bigdaz]

The Fan draws cold air in around the back of the engine and blows some onto the barrells and some out of the vents.
The air coming out of the vents is for the heat exchangers so you dont really need the pipes on your set up.
It wont hurt to just leave them pumping air out the bottom as its not depriving the engine of cold air.
There is an argument that if you block off the fan outlets (usually with a spray can lid ) this will give more cooling over the cylinders but but also another thought that because of the way the ducting was designed it could disrupt the air flow.

The other thing to consider if you remove the pipes is the holes they go through in the tinware. They must be blocked off to stop hot air from the exhaust coming up into the engine compartment.

If it were me I would look out for some good heat exchangers and make use of the heater.

Otherwise just leave the pipes dangling.

 

[Trikky2]

It wont hurt to just leave them pumping air out the bottom as its not depriving the engine of cold air.

Otherwise just leave the pipes dangling.

Wolfsburg were not aware of this - better let them know.

 

[kevlar]

Thanks all, If I remove j tubes and fit exchangers will this effect the sound of the exhaust , I have a bugpack system , it sounds superb

 

[Trikky2]

Thanks all, If I remove j tubes and fit exchangers will this effect the sound of the exhaust , I have a bugpack system , it sounds superb

Shouldn't affect it.

 

[Nick-Rackham]

Excuse the ignorance but I may be in the same position in the future. I was going to block off the outlets from the fan housing with rattle can lids and cover up the holes in the tin. This is on the basis that if I had heat exchangers fitted but didn't have the valves open, then there wouldn't be any air flow through, which is the same effect as blocking the outlets in the fan housing. Make sense or is my logic flawed?

 

[67panel]

NO it vents out the rear of the heatex valve when flap shut.could be why its not a good idea to blank the pipes off.

 

[Nick-Rackham]

NO it vents out the rear of the heatex valve when flap shut.could be why its not a good idea to blank the pipes off.

My flawed logic Cheers, Nick

 

[Trikky2]

When the flaps are closed there is a small opening left open so that a small amount of cooling air still flows over the innards of the heat exchanger.

This flow is there so that, on a hot day going up a steep hill or on the motorway, the heat exchanger doesent overheat. The inside is made of aluminium which conducts heat very well but cannot resist being red hot without melting.

When its cold the air used by the heater is not important and when the weather is hot the heater is not in use, so max flow is supplied to the engine.

So to re cap (though this subject has been covered on various forums) the small vent in no way takes the same flow as that used when the heater flaps are open.

Even when the heater is in use there is a fair amount of flow restriction compared to leaving the pipes open. Hence if you leave the pipes unconnected and not blocked off you will be depriving the engine of cooling air.

On the other hand, old melted heads and pistons can be turned into quite attractive ornaments or ashtrays, which look nice on dark wood sideboards. :lol:

 

[sharky71]

On the other hand, old melted heads and pistons can be turned into quite attractive ornaments or ashtrays, which look nice on dark wood sideboards. :lol:

/\/\/\/\/\/\/\/\/\ :lol: :lol:

 

[89Rallye]

Anyone know whats good (ie neat and tidy) for blocking off the outlets on the fan housing?

My old engine came from the states with peanut jar lids which were a perfect fit.. So was thinking of something similar.

 

[kevlar]

there was a third hole in my bottom tinware I blocked with a sandwich of 2 3 inch washers with a nilock nut and bolt through centre, kev

 

[jonboylaw]

^ I used a couple of jam jar lids to the same end


Sent from my GX64 SatCom phone using Tapatalk

 

[matt-me]

Anyone know whats good (ie neat and tidy) for blocking off the outlets on the fan housing?

My old engine came from the states with peanut jar lids which were a perfect fit.. So was thinking of something similar.

cut down red bull cans...when i was suffering a bit of overheating in France one summer, i used red bull cans for the fan housing and blocked off the remaining holes in the tin ware with small kronenberg cans. The idea was to force more of the cooled fan air down through the flaps on to the heads. It improved and got me home by driving on temperature

I've read a thread somewhere about leaving a hole in each the size of a 5p coin, there was a recommended reason for this, but can't remember what.