[TR] TR6 evaporative filter - function or setup question

[Mark Hooper]

Hi Randall:

Hmmm, engine is low milage after re-build. Alloy valve cover. Power is very
good, idle is not. I have always attributed that to poor hand-done S2 camshaft
or weird distributor bearings.

Carbs are 3 standard ZS units rebuilt by Paltech on Good manifolds. Which
restrictors do you refer to?

Cheers,

Mark


________________________________________
From: Randall [tr3driver at ca.rr.com]
Sent: April 27, 2010 6:32 PM
To: Mark Hooper; triumphs at autox.team.net
Subject: RE: [TR] TR6 evaporative filter - function or setup question

> Why does this have such a huge impact on the engine (especially idle)
> when the pipe to the valve cover is unplugged?

Well, it's basically an intentional vacuum leak.  By blocking off the flow
into the emission ports on the carbs, you are changing the mixture.

In theory, though, the crankcase should be a dead end, so it should quickly
pull a few inches of vacuum and then go back to where it was.  It should be
the line to the carbon canister that makes a big, permanent difference.
Could you have tired rings, or some path for air to get into the crankcase?
Wrong filler cap, perhaps?

BTW, you do have the restrictors on the ports, correct?  Probably, for a
triple setup, you should really have smaller restrictors to keep the
'emissions' airflow the same relative to the flow past the throttle plate.

-- Randall