TR6 1973 TR6 oil between the head and engine block?

[sundown]

I took a spirited ride yesterday got home and lifted the hood and noticed what looks like engine oil around the plugs and some on the block. The car runs fine no smoking and a lot of power. Nice steady vacuum reading at 17. It doesn't look like it's coming from the valve gasket I can't see any oil on the side of the head where it might leak down. Thanks for any input

 

[Geo Hahn]

Not that familiar with TR6s -- but I would think an oil leak between the head and engine would be pretty localized and not be on the plugs.

...noticed what looks like engine oil around the plugs and some on the block...

Coolant, once it is combined with dirt or grease in the area, can look a lot like oil. If you clean the area and cause the leak to recur you may be able to better identify what it is -- which is what you must be sure of to identify what is going on.

 

[titanic]

If the oil is in the spark plug "wells", I would think that if would have to come from the valve cover or the spark plugs. If at the head/block interface, maybe some blow by from the crankcase. Oil leaks on that side of the head seems to be pretty common with TR6s. I cured mine by coating the head gasket with sealer when the head was removed for work. Since you noticed the problem after a "spirited drive", that would seem to indicate crankcase pressure from blowby and/or a problem with venting.
Berry

 

[sundown]

Should this engine have a vented oil cap?

 

[poolboy]

That's a fairly common place for oil to show up when there is inadequate relief of crankcase pressure.
Len Reckenberger specifically mentions that scenario in his "SIX TECH" manual.
The TR6 has a "closed crankcase ventilation system" No vent in the oil filler cap.
The pressure from blowby would normally be taken care of by the 2 evacuation ports on the right hand side of the twin 175 ZS carbs in the post 69 cars.

 

[Gliderman8]

I actually had oil coming out of the riser tube for the dip stick on my '73. I followed poolboy's recommendations for crankcase ventilation and my oil problems went away!

 

[sundown]

I do have the crankcase venting into the carbs. Although the only vent going to the CC is the gas tank. I did way with the tee that goes from the carb and crankcase that feeds into the CC could this be a problem? Could be another way to vent the blow by?

 

[poolboy]

No..I don't think that's the issue. Instead of having the carbs suck on the valve cover and the cc, you have the carbs just sucking on the valve cover which should make the relief of crankcase pressure by the carbs even more effective.
There is another way, which does not use the evacuation ability of the carbs.
Some people with ZS carbs have used it, so have people who replaced their ZS carbs with SU's or Weber DGV carbs.

This :
https://www.goodparts.com/shop/index.php?productID=253

Installed like so:


When I rebuilt one of my engines, I had oil show up where you described, but after the rings broke in and sealed, it stopped.
Your engine isn't new, is it ? Or was this something that just started 'out of the blue' ?

 

[sundown]

I did just replaced the valve cover gasket after I adjusted the valves . The engine has been rebuilt rings,bearings, thrust washer, etc not too long ago maybe has 10,000miles on it. I just started to notice this issue

 

[poolboy]

It might be a good idea to do a compression test..see if the rings are containing the pressure or allowing more blow by than normal.

 

[sundown]

I did a vacuum test and the needle was steady around 16-17 indicating from the reading on the gauge normal motor

 

[poolboy]

Not necessarily. What you did was like trying to take a persons temperature with a stethoscope.
What you did not test was compression.