Jim,
I suppose a water leak that is disturbing your oil and not seating piston
rings.
There could be a leak at the bottom of the liners from the figure 8 gasket.
Easy to find when you remove the oil pan and have a look there.
If the head gasket leaks you can see water in the tappets. Remove the rockers
and pull out the push rods if they stand in deep water.
Your compression figure is quite low for a racing engine. My worst cylinder
has a compression of 220 PSI. The best one 230 PSI. Compression rate of
11,3:1.
After honing did you change rings too?
I do a violent running in procedure to brake in the rings.
----- Original Message -----
From: "Jim Gray" <toodamnfunky@comcast.net>
To: "Friends of triumph" <fot@autox.team.net>
Sent: Saturday, February 23, 2008 9:15 PM
Subject: [Fot] Motor troubles & compression
> Hey group,
> I am having some disturbing issues with a fresh motor. The first symptom
> was overpressure
> in the crankcase. My catch tank is collecting an oily, watery vapor
> which settles as a whiteish foam.
> The catch tank is plumbed from the fuel pump cover plate. I still have
> to properly vent the valve cover
> in lieu of the tiny cap vent hole.
> Oil also bubbles out the dipstick port in the block. On fresh oil the
> oil pressure is 75 lbs +/-.
> The foam is also present on the bottom of the oil cap and on the
> underside of the valve cover.
> As I put some miles on it my oil pressure drops below 40 PSI. I suspect
> if I change the oil
> again the pressure will go back to normal as it did last time. When
> draining the oil there was
> no evidence of water. I have about 40 miles in the motor now so I would
> expect the rings to
> have seated. It's not a fresh bore, just a hone job.
> My compression test shows 180 psi in # 1 and 164 even across the other
> three.
> All the plugs were out when I tested the compression.
> Could there be a common or similar leak in 2-4 and bleed compression
> into the crankcase ?
> Anybody know what a fresh bore should read ? The head has been milled
> .075 and the liners and
> head gasket trimmed to match the new combustion chamber profile.
> Gasket sealer was used but I am a bit concerned as there are a few thin
> spots.
> Could it be exhaust gases leaking into the crankcase causing the
> overpressure and vapor in
> the crankcase ?
> Then that leaves the drop in oil pressure, is the vapor affecting the
> viscosity ?
> Also, there is no smoke or steam coming from the exhaust and there is no
> smell of
> coolant. I plan to pull the head and have a look around but maybe there
> is something else I
> should look at before I take it apart, any idea's ?
> Any advice would be appreciated.
> Jim Gray
> RMVR
> _______________________________________________
> http://www.team.net/donate.html
>
> Fot mailing list
> Fot@autox.team.net
> http://autox.team.net/mailman/listinfo/fot
>
> You are subscribed as tr4racing@googlemail.com
_______________________________________________
http://www.team.net/donate.html
Fot mailing list
Fot@autox.team.net
http://autox.team.net/mailman/listinfo/fot
|