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Re: blue smoke/valve guides/timing

To: triumphs@autox.team.net
Subject: Re: blue smoke/valve guides/timing
From: egilk@oslonett.no (Egil Kvaleberg)
Date: Mon, 20 Nov 1995 07:00:22 +0100
Newsgroups: mail.triumphs
Organization: Siving Egil Kvaleberg AS
References: <v01510100accf5a94fcb1@[130.123.73.26]>
In article <v01510100accf5a94fcb1@[130.123.73.26]>, Liquid@massey.ac.nz wrote:
>         Having reassembled and fitted the head, the car was taken for a
> test run, with the hope that the embarassing smoke problem had been laid to
> rest.

I don't remember your symptoms, but let me mention:
        Blue smoke: Burnt oil
        Black smoke: Excessive fuel

        Blue smoke, mostly on overrun: Probably valve guide
        General blue smoke (?): Piston oil control rings

> If so, are they intended to be used with valve seals?- the machinist
> said they would be OK without.  I can't remember what the original guides
> were like, but these new ones are not smooth, but rather, have equally
> spaced circular grooves along their length. 

I would assume that valve guides with grooves would be designed for use
with a seal? I imagine that oil would be sucked along the grooves and
into the cumbostion chamber.

Another thing: It is really on the inlet where the seal is needed the
most, due to the high vacuum present.

> Should I reset the timing back to original specifiction? 

I would have tried it.

> How
> can I tell if  I advance the timing too much? - I'm not really sure what
> pinking sounds like  (is it unmistakable?)

The sound is unmistakable. It is not a good thing, it will harm the
pistons and rings in the long run.

If you advance the timing beyond the origial spec (max. 5 degrees, say), and
go up hill with a hot engine, low speed, high gear and throttle open,
you'll sure enough hear it. A short test like this will not damage
anything, just educate you!

> and have also read somewhere 
> that modern petrol has additives that prevent it . 

Yes, but those additives are accounted for in the octane rating.

> Does setting the timing
> statically and dynamically yeild different results? 

No, in case a number of conditions are met (we've covered those recently).

> Also, as the problem
> is intermittent, could the advance mechanism be sticking?  i.e. maybe it
> has been stuck when I set the timing, but has subsequently been
> intermittently settling back to a more retarded position.

Use the ignition strobe lamp to verify that it is advancing properly at 
higher RPM. Just remember that advance is often stated as camshaft
degrees - double those values to get crankshaft degrees.

Egil

-- 
Email: egilk@oslonett.no  Voice: +47 22523641/92022780 Fax: +47 22525899
Snail: Egil Kvaleberg, Husebybakken 14A, 0379 Oslo, Norway
URL:   http://www.oslonett.no/home/egilk/

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