[Roadsters] Valve Cover discovery...

[Daryl Smith]

Well, since I've been having problems in this area I guess it's my turn to 
log in.......

My early '66 1600 had the vent tube out the left rear of the block, and no 
valve cover outlet.
With the EFI conversion, I elected to block that off and use the later valve 
cover with the hose attachment tied to the intake (to lower emmissions 
direct to atmosphere).
I figured it would draw enough to eliminate the problem of blowby building 
pressure and causing oil leaks.....It's pretty much the same setup as the 
later SU cars, so it shouldn't be a problem......
3 oilpan gaskets later, I still have excessive leaking from the oil pan. 
Putting a vented oil filler cap has lessened the oil leak, so there does 
seem to be a pressure buildup problem there.
This is on a fairly fresh rebuild stroker engine with minimal blowby at 
idle...I haven't done a leakdown test, but compression test reads 185 -195 
psi.
Part of my oil leak problem may be a .010" height difference between the 
block and timing cover at the oilpan, but that should have been fine with 
gasket sealant etc. which I have used......

So, regardless of what setup you use, make sure there is sufficienct venting 
of the block!
Does it need to go to the aircleaner? No, that simply recirculates the 
blowby back thru the engine decreasing emissions directly to the atmosphere 
(recomended unless you are racing). A small filter on the vent tube should 
work, but you may find it dripping oil eventually........

Daryl

----- Original Message ----- 
From: <fairlady1964spl310 at yahoo.com>
Subject: Re: [Roadsters] Valve Cover discovery...


>I may know a little about this....
> It is my understanding, that there were a couple different configurations 
> for
> the crankcase ventilation on the early 1500 roadsters.  The earlier (63, 
> 64)
> have a breather tube that goes from the engine backing plate to the upper,
> left, rear corner of the block.  These used a breathable oil cap like on 
> the
> 1000 and 1200s....an odd looking, painted cap containing metal mesh as a
> filter. There was no rear hole in the valve cover.  The other 
> configuration,
> is a two piece oil cap (usually chrome) with a tube that connects to the 
> air
> cleaner.  Again, no hole in the valve cover.  The 1965, R16, I believe, 
> was
> when it changed to the vented valve cover we all know and love.  Regarding 
> the
> mechanical purpose of "crankcase ventilation", I've no clue.
> Patti