Technical My PCV wows fix .

And now for something challenging out of the shed of Shrappy's Originals , after hours of course , can't pay the bills doing homers !

So , I've been having a weeee issue with Oil Spray over the RH side wind screen , firewall , body etc at open road (100kph) speed on the 27 Roadster. Due to No PCV Valve system I suspect .
This Old Weiand manifold only has one small vacuum port , which is used for the distributor, and No vacuum port for a PCV Valve system. Im guessing the old Draft Tube was what was used back then , which results in an oily undercarriage.
From what I read up on , and what I learnt ( mostly from Tommys PCV Tech post ) , was that we definitely need a PCV system , but what I also knew , was that I didn't want to make any visible changes to the old Weiand manifold. Lots of options were on offer , but none to my liking.
After a weee while of giving the Grey Matter some late night work outs , , , this is my solution.
Basically a PCV Valve system , attached on the manifold plenum underside ( in the block valley ) out of sight.
Lots of pros , mostly the unseen on this manifold one , but the one Con ? If the PCV Valve starts playing up , it's manifold off to replace.
From here , the pics can do the talking ,

Bit hard to tell in this pic , but the RH side wind screen , firewall and body is well coated in a mist of engine oil.

The only vacuum port on this manifold. Used for distributor.

Screw in PCV Valve.
I made up a tube shield , to try and stop any direct splashes of oil getting into the PCV Valve.
Underside of the manifold plenum. Shield faceing the back of the block
PCV Valve screwed in place.
When I was drilling , taping and fitting the 1/4 bsp fitting to the underside of the manifold , I found the casting to be very Gummy and I lost faith in everything staying put for any length of time , so I decided to add a support bracket.
I also added a saddle over the Tee fitting. I used a Tee fitting for just in case the PCV Valve isn't big enough ( this was the biggest screw in type I could find and usually found on the side of a Nissan motor ) and I need to add another.
The fixings used are 3/16 Button head set screws ( they were fun to get in through the intake runner ! ) . I also added a screen just to be sure splash Oil won't land in/on the PCV Valve.
Result ? About An hour and a Halfs driving at our open road speed limit ( 100kph/60mph) and no oil mist over any part of the car .
MINT

Shrappy

 

Here's Tommys PCV TECH thread that helped me get a better understanding on the PCV Valve system.
Well worth a read through.

 

Good job! I am in the process of fitting a PCV to a 138 Grey motor (in an FB Holden,) that screw-in valve gives me an idea. The locknut on that bolt through the inlet manifold is a good idea, I wish I had put one on the bolt which fell into the inlet manifold (from the LP gas set-up on the carb,) and got swallowed by a piston.

 

Because I'm paranoid about small bits finding their way to the internals of the engine , I even hit the end of each set screw with a couple of Center Punch dots , right on the edge , to stop the nut coming off should it work its way lose ?


Shrappy

 

I would have just changed to a carb that had vacuum ports to hook up the PCV and vacuum advance

 

Hit the bolt at the top of the nut, then it won't back off at all.

 

Yeah , I thought about that , but if I need to modify this , I can just give the end of the bolt a zing with the sander to clean off the Center dot and get the nut off with ease ,
Cheers

 

I follow your thinking, but once you put the intake back on do you want it to come loose? I always think about the what if I want to take it apart side. However, I also look at how well it will hold up once finished. That strap is for support, if the nut backs off, no support and maybe a vacuum leak to boot.