replacing hot air ducting
Posted: Tue Dec 04, 2012 4:48 pm
After a cold drive yesterday I decided it was time to replace the worn out ducting bringing hot air from the heat exchanger into the cab. Last time I was underneath I could see it was in poor shape. I looked at the old posts about it but noted a difference between the stated tubing diameter needed and what I think the manual is telling me I need.
Basically, the older posts (2008) suggested 20 feet of 3" (75mm) tubing was all that was needed. From the book it looks like: 500mm, 400mm and 1100mm of 70mm diameter ducting; 250mm of 75mm diameter; 250mm and 440mm of 50mm diameter and lastly 420mm and 800mm of 42mm diameter (ignoring for the moment the warm air feed to the carb intake).
The tubing I had in mind was this: http://www.ebay.co.uk/itm/140671550957? ... 1423.l2649
It'll handle up to 300'F apparently and I can't imagine the air temperature downstream of the heat exchanger is anything close to that. Am I OK at that temperature rating do you think?
Do the guys who re-ducted their steeds back in 2008 disagree about the diameter's actually needed? It'd be a lot cheaper for me to order a single length of one diameter.
Any thoughts?
Tony
Basically, the older posts (2008) suggested 20 feet of 3" (75mm) tubing was all that was needed. From the book it looks like: 500mm, 400mm and 1100mm of 70mm diameter ducting; 250mm of 75mm diameter; 250mm and 440mm of 50mm diameter and lastly 420mm and 800mm of 42mm diameter (ignoring for the moment the warm air feed to the carb intake).
The tubing I had in mind was this: http://www.ebay.co.uk/itm/140671550957? ... 1423.l2649
It'll handle up to 300'F apparently and I can't imagine the air temperature downstream of the heat exchanger is anything close to that. Am I OK at that temperature rating do you think?
Do the guys who re-ducted their steeds back in 2008 disagree about the diameter's actually needed? It'd be a lot cheaper for me to order a single length of one diameter.
Any thoughts?
Tony