Muguchagas gragacigiagas, Mariano. In fact, I wondered how a native speaker of Spanish would treat the non-syllabic part of <ue> and <ie>. But i suppose that in you substitution game you'd say <buan tiampa, buen tiempe, buon tiompo> etc.
----- Original Message -----
From: Mariano de Vierna y Carles-Tolr√°
Sent: Friday, April 06, 2001 4:48 PM
Subject: RE: [phoNet] Ludlings
   V --> VgV for all vowels.
e.g. in Spanish:
   <bueno tiempo> --> <bueguenogo tieguempogo>, I presume.
(Writing just as a Spanish native speaker not as phonetist that i'm just amateur) I think that i would transform in that way:
    buen tiempo ---> bugueguen tiguiegempogo /buguegen tigiegempogo/
The components in diptongs are treated independently each one. 
In another example:
    rosa y azul --> rogosaga igi agazugul
Would happen that althought < y > between vowels has the pronuntiation as a consonant, that is the [j] (with an up-down circunflex instead of the point), it would be understood as a vowel sound. But, in Spanish also, if the following word starts with /i/ then the conjunction < y > use to change to /e/, < e >, as for example in:
   bonito e interesante
So that allophony for this particular word -the copulative conjunction- is quite extreem and part explicit. The disyunctive conjunction also has explicit allophony, as it is /o/ but becomes /u/ if it's followed by /o/.