[Healeys] high oil consumption

[Bob Spidell]

I believe syn oil is a bit 'thinner'--even for the same nominal 
viscosity; I'm going on hearsay--so a little more consumption may be 
expected.  My new Mustang GT uses about a quart of 5W-20 semi-syn every 
5K miles or so, which is about the same as my 2008 Mustang GT used 
(consistently over 135K miles).  An engine has to use some oil, a very 
thin 'smear' should be left on the grooves in the cylinder walls to lube 
the rings and it gets burned on every combustion cycle.

What kind of valve guides and seals does he have?  I believe bronze 
('bronzium,' silicon bronze, etc.) guides require a little more 
clearance from the valve stems for heat expansion (I've heard 0.003"), 
this might allow a bit more oil into the combustion chambers.  Most 
builders laugh at the stock O-ring type seals; mine used a customized 
'top hat' seal that they use on the race engines they build.

Bob

On 9/17/2019 7:48 AM, warthodson at aol.com wrote:
> Bob,
> The owner is aware of the issues with oil & I think he is using 20w/50 
> Castrol synthetic oil. I will confirm at the meeting. On the trip to 
> Conclave no one noticed any thing unusual about his exhaust. Some did 
> say they say a "little black smoke, occasionally". I will be 
> interested in seeing the plugs. If not rings, how else could oil be 
> getting into the combustion chamber?
> Perhaps the valve stems could be leaking. How could we test for this? 
> How about valve stem seals leaking?
> Gary H
>
> -----Original Message-----
> From: Bob Spidell <bspidell at comcast.net>
> To: healeys <healeys at autox.team.net>
> Sent: Tue, Sep 17, 2019 9:22 am
> Subject: Re: [Healeys] high oil consumption
>
> What brand/viscosity oil is he using?
>
> If it really isn't leaking it can only be burning it; I'd expect quite 
> a bit of blue smoke out the tailpipe.  My BJ8's engine was rebuilt a 
> couple years ago and uses some, less than this one, but isn't leaking 
> it--I was under it yesterday--and I only get a little blue smoke after 
> a long downhill run in gear.
>
> Bob
>
> On 9/17/2019 7:16 AM, warthodson--- via Healeys wrote:
> Our local AH club will be checking a BJ8 for high oil consumption this 
> weekend. He says it is not leaking out. We will verify that when we 
> inspect it.
> He added 8 quarts of oil on the round trip to Conclave recently (2100 
> miles total). The engine was professionally rebuilt in 2011. The 
> engine builder has recently retired & moved to a Caribbean island so 
> we cannot contact him, true story.
> In 2012 he used 6 quarts of oil on a 5000 mile trip. About 2-3 years 
> ago I checked the compression, performed a leak down test & inspected 
> the spark plugs. Every thing was in the normal range.
> My question is: If the engine passes all the usual tests this weekend, 
> what are some of the unusual ways you have come across that could 
> cause high oil consumption & how would we test for them?
>
> Gary Hodson
>
>
> _______________________________________________
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation  $12.75
>
> Archive: http://www.team.net/pipermail/healeys 
> http://autox.team.net/archive
>
> Healeys at autox.team.net <mailto:Healeys at autox.team.net>
> http://autox.team.net/mailman/listinfo/healeys
>
> Unsubscribe/Manage: 
> http://autox.team.net/mailman/options/healeys/warthodson@aol.com
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20190917/5ff3aaee/attachment.html>