Please give me the names of some search engine experts (people but not
lawyers) in the Silicon Valley area so that I can contact them and ask
questions about prior art on search engines for the purpose of writing
a patent.Thank you.

I can recommend someone who might be very helpful, except for your
"not lawyers" requirement. Since eventually you'll need a patent
attorney, why not?

askdavid-ga

If I may make a suggestion, you don't need word of mouth reports from
individuals, you need to know what's been published on the subject in
tech journals and in previous patents since published material is what
will really have standing when the PTO is deciding what is prior art.

From previous experience, the largest lawfirms around Silicon Valley
have relationships with many of the  major players, so while they have
the largest knowledge base, they often cannot provide useful advice
based on that knowledge to new players in the field.  I'd rather talk
to people who can speak unrestrained by previous legal agreements.