Subject: [TR] Any one have this problem?

From: "Andrew Uprichard" <[email-masked]>
Date: Sun, 26 Aug 2012 10:58:33 -0400

List:

After rebuilding the TR250, I noticed a distinct "click" from around my feet
and in sync with engine revs.  Turned out to be the servo non-return valve.
Advice was to keep trying until I found a valve which didn't "click"  So far
I have tried 5 (thanks to Marv Gruber for two) and still no luck.  The TR250
valves have three lugs and twist in a third of a turn, so they are harder to
come across than the later, TR6, variety.

Does anyone have experience with this and could it be something other than
the valve itself, say within the servo ?

Or if anyone has a decent valve they'd let me try, that would also be great.
Thanks in advance,

Andrew Uprichard
1962 TR3B
1968 TR250
1957 small-mouth (slow restoration)

** [email-masked] **

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: "Randall" <[email-masked]>
Date: Sun, 26 Aug 2012 08:27:10 -0700

> and in sync with engine revs.  Turned out to be the servo 

I don't have any experience, but my guess is that there is something odd
going on with the intake manifold vacuum.  That valve should only move when
the inlet vacuum goes above or below the vacuum inside the servo, so I think
the rhythmic click means the inlet vacuum is going up and down.

You should be able to confirm that theory by connecting a vacuum test gauge.

I'll further guess that you have a fair amount of "lope" at idle, caused by
the aggressive cam profile (this is the engine with 170+ bhp, correct?),
which might explain the vacuum variation.

One solution might be to add an in-line check valve in the line leading to
the servo.  Without the direct connection to the servo and firewall, you
probably won't be able to hear it operate.

-- Randall