hot air riser flex extrension

[Jim Bathgate]

I've got a 1968 F350 with 360 engine. Mostly original. To fix the hot start problem, I'm putting a 1" phenolic spacer under the carburetor. Unfortunately this creates a gap between the air cleaner heat riser input and the riser tube from the exhaust manifold. This tube is 2.75" in diameter. Does anybody know where I can buy some flexible metal tubing (there's about a 1/2" offset to also deal with) that can bridge this gap? Or can I just use a few wraps of the aluminum tape used in housing heating ducts?

[Ohiotinkerer]

I did the same thing with a spacer and used a piece of aluminum roof flashing........cut it to the width and length i needed........which reminds me that I need to finish fastening it properly and get the strip of duct tape i wrapped around it off...... .........I'll post a pic in the morning........

[Jim Bathgate]

Sounds good. I'll give that a try. I guess a SS hose clamp top and bottom would hold it in place. Thanks

[Ohiotinkerer]

Here's a couple shots of mine......I really need to get rid of the duct tape! It slips over the outside of both the riser and air cleaner but could probably be put inside also......

IMG_20181003_135017_hdr_kindlephoto-270128850.jpg

IMG_20181003_134933_hdr_kindlephoto-270197011.jpg

[Jim Bathgate]

Looks good other than the duct tape. I'm not sure regular duct tape will hold up to the heat in the engine compartment. I was thinking either hose clamps or that aluminum tape they use in furnace sheet metal construction. By the way, did you know that in most municipalities it is illegal to use duct tape on ducts? Of course that doesn't stop NASA from stocking each manned space flight with a roll of duct tape. Thanks for the photos.

[Ohiotinkerer]

It's been on there for 2 years and has held so far and it only gets driven in the summer when its hot so I'm actually surprised it's lasted........but it was intended as a temporary fix........and as normal in my life it keeps getting shuffled to the back burner...... ........no problem on the pics......glad to be able to help........