re 5ktq vacuum hose sizes...

["Smith, Kirby A" <kirby.a.smith@lmco.com>]

MSV96@aol.com, aka Mike Veglia, asked:


What size and type of hose is the popular choice for vacuum line replacement
on the 5ktq? I recall a suggestion of 4 mm high pressure fuel hose...not a
common item. I have found 3.5 mm cloth covered vacuum line but it looks
small
compared with what is in the car. I have given up on using some viton or
epdm
"pump tube" from work as they are not really suitable for the temps and/or
oils best I can tell (and viton tubing is outrageously expensive).

So, size? Type of hose? What is the consensus? TIA
------------------------------------
I'm surprised you find viton to be unsuitable due to temperatures.  I put
Viton O-rings on my turbo corvair push-rod tubes (air cooled engine with
600F head temps) in 1967 and they lasted through 100s of laps and 100k mi
before I tore the engine down 20 years later.  They had survived intact and
only taken a set that slowly recovered sitting on my work bench.
Flexibility was unimpared.  I can't speak to the suitability of specific
viton hoses for vacuum line; they would require sufficient wall thickness to
avoid collapse.  Otherwise, I would doubt you could harm one unless it was
draped over the turbo turbine inlet.

                .... Kirby   (Kirby A. Smith)
                              2 x 1988 90q
                          New Hampshire USA