PCV valve nobbling tickover - solution?

[Nic Bowman]

Hi, my TR4a has a Positive Crancase Ventilation thing, (PCV - as they all do?) connecting the rocker cover to the inlet manifold. If you take the top off the PCV, the bit that is meant to block the vent hole is poorly guided, and often misses the hole. This causes an air leak, which causes the tickover to race.

 

The whole PCV idea seems a bit Heath Robinson to me.

 

I am inclined to put it in TR4 mode, pipe rocker cover to the air filters.

 

Is this a good idea? Any better fixes?

 

Ta

 

 

Nic

ps, new PCV's are also £54!!

[stuart]

Renewing the pipes (correctly shaped ones) and the diaphragm and giving it all a good clean should restore it to health.

Stuart.

[JJC]

Renewing the pipes (correctly shaped ones) and the diaphragm and giving it all a good clean should restore it to health.

Stuart.

 

Yes but is it easier to set the engine up by just venting the rocker cover to the open air? Obviously you need to blank the hole in the inlet manifold.

[Nic Bowman]

Hi, I am inclined to worry that the PCV lets air in at tickover and will always make the setup tricky, and thus dumping it is a good idea. Mine has all new pipes and is in good shape, just a poor design internally.

 

Does the vent to atmos of the rocker cover smell oily? The car smells enough already!

 

 

Cheers

 

 

Nic

[67_gt6]

Hi, I am inclined to worry that the PCV lets air in at tickover and will always make the setup tricky

 

 

If it is in a proper state of repair it doesn't

 

Andy

[Badfrog]

Hi,

 

A word of caution: the hose from the PCV goes into the manifold, after the carbs. So make sure you plug it right when removing the blasted gizmo.

Then, you can connect the rocker cover to an oil catch tank. BUT....

The TR4A engine has no crankcase breather (hence the PCV). So if you don't manage some form of breathing device, crankcase pressure will blow oil through any available leak or passage.

To avoid this, I have installed an electric fuel pump and used the pump location to ensure breathing with a metal plate bearing a bit of metal tubing, a "no-return" valve and a rubber tube to the oil catch tank (2 liters).

 

Badfrog

[ChrisR-4A]

Hi Nic, I removed the PCV assembly from my 4A over 10 years ago and vented the rocker cover with a plain piece of hose over the top of the carbs and down to just past the chassis, held there with a tie wrap. With ref to the aditional crankcase breather as used on a TR4, the hole to fit this is still there on a 4A but is pluged with a core plug. I removed my core plug while engine was still in car, a bit of a fiddle and fitted the breather pipe off a TR4 purchased second hand from one of the TR breakers. This setup works fine and always passes the MOT.

 

Chris

[Nic Bowman]

Cheers Chris and Badfrog.

 

Where is the blanked breather with the core plug in it? I dont want to fish out the wrong core plug!

 

Thanks

 

Nic

[Badfrog]

Cheers Chris and Badfrog.

Where is the blanked breather with the core plug in it? I dont want to fish out the wrong core plug!Thanks

Nic

 

 

Hi Nic,

 

It's down, left and rear of the engine, about 2 inches above the sump and the same from the end of the block (roughly). The pipe has a metal plate to be bolted on one of the sump bolts so you can't miss the right hole. Besides the pipe will fit tight in the plug hole (once the plug is removed of course).

 

Cheers,

 

Badfrog