Triumph Repair: Crankcase/Rocker cover vent, weber dcoe, free flow exhaust


Question
1971 spitfire
1971 spitfire  
QUESTION: Hey Jim, I have a 1971 Spit with a 1296 in it. I've added  a
4-2-1 header, free flow exhaust, Pertronix ignition, flame
thrower coil new plugs and wires, and a set of Weber DCOE's
with a cannon intake manifold. It runs really good. My
question to you is, should the rocker cover vent be hooked
to a vacuum somehow? I've since had an oil leak/head gasket
fail. Since the Webers don't have a vacuum hook up like the
original Zenith Stromberg, I just put a small air filter on
the rocker cover line. I've attached a picture so that you
can seee what I'm referring to. Any info on this would be
greatly appreciated. Thanks.

ANSWER: Jay,

What internal work was done to take advantage of the twin DCOEs?   And what kind of compression ratio are you running?   

Yeah, it'd be a good idea to pull the intake manifold and tap a fitting to help pull blowby out of the crankcase.  Either use the mechanical fuel pump hole (you're running electric pump, right?) or do like I did on my autocrosser and put a line on the dipstick tube.  

Not a bad idea to hang a small catch bottle between the block and intake to catch most of the oil that gets pushed up.  Otherwise instead of leaking you'll be burning.  For the catch bottle to be effective it needs to be sealed and able to hold some pressure/vacuum without collapsing.

Also you might check with someone like Ted Schumacher at TSI Imports for a better head gasket.  There are some better ones out there.


Cheers,

Jim


---------- FOLLOW-UP ----------

QUESTION: Jim, I haven't done any work yet to the internals of the
engine. I plan on a new cam, triple angle grind on the intake
valve seats, head flowed etc. Do you have any pics that I
could check out? Thanks  for the help.

Answer
Jay,

Sorry, no pics available at this moment.  

One friend took a salsa jar (literally), punched 2 holes in the lid and used hard steel pipe going in and out.  You don't want the pipe going to the intake going too far into the container as you don't want to suck oil into the intake.

You may find that when you rebuild the engine you'll eliminate the worst of the problem as what you're seeing is blowby from the cylinders pushing oil out of the various seams in the engine.  


Cheers,

Jim