Just wanted to let you all know that my efforts to eliminate the intake of oil via the pcv system have not proven successful. I had tried inserting the crankcase filter material in the baffles but, as someone suggested, once it filled with oil, the oil made its way into the pcv and into the carb. I took a 225 mile cruise on Sunday and consumed 3/4 quart of oil. I am ready to resign myself to checking/filling oil weekly.

To date, tried:

breather instead of pcv/hose - detected some oil escaping block at rear of oil pan and the breather filter media became soaked with oil
pcv/hose with filter media in valve cover baffle- oil vapor soaks the filter media and still escapes via pcv

One item I haven't tried is the breather with pcv valve built in (not the $7 breather with the pcv 'nipple' that requires a monstrous hose to use). The item I'm looking at is $30 but I suspect it will show same/similar results as the pcv/hose with filter media in valve cover.

I am wondering if an OEM volume oil pump would be the answer. One concern I have is that the engine may not produce sufficient oil pressure with the stock pump if the aftermarket cam and bearings are not as 'tight' as the OEM setup was.

With the high volume Mellings oil pump and 5w30 after warm-up, I am pushing 25-30psi at idle (700rpm) and approx 45-50psi at cruising speeds (1500-2500rpm).




[Modified by TedH, 10:20 AM 3/23/2004]

 

Your pressures are fairly low. They're actually lower than mine with a stock pump (I'm at 40 idle, 55-60 at rpm). Don't think a stock pump is the answer.

I'm wondering if your problem isn't really the PCV system but rather badly sealing pistng rings? That would let pressure go into the crankcase whitch would greatly increase the amount of air pushed out the PCV system.

I would suggest a leakdown test to verify.

 

I have a pcv with no baffle and am experiencing some oil consumption too. I've followed your trials with this and will be watching this thread too. I have considered new valve covers with a baffle but if that won't stop oil consumption either...what's the point?

Brett :thumbs:

 

Markus,

Good suggestion. Will try a leakdown test this weekend.

 

I think that it might be a combination of both - bad sealing piston rings and oil comsumption through the PCV... However - the bad sealing rings can be a result of too much pressure building up in the crankcase... I personally fixed my problems with a crankcase evacuation system (no PCV - just a hose from the breathers to the collectors on the headers)... However - this system only works with open exhaust... The best option would be to either use open style breathers (not the restrictive type with only a few breathing holes on the bottom) or routing hoses from the breathers to a breathable overflow tank (just like forum member lotahp)..

 

I don't know if you have ever pulled the intake manifold off or not, but these engines had serious problems with oil pullover from the intake gaskets on the lifter gallery side of the manifold. No smoke, they just consumed a quart of oil every 200-400 miles. It didn't show up on the plugs either. If the gasket has never been off, you might consider this area.

 

Just replaced the intake gaskets along with generous amounts of gaskacinch gasket glue from Edelbrock. That was my first idea to correct the consumption problem. I'm pretty sure I have eliminated the intake gaskets as a potential problem.

 

You really need to leakdown test this engine. I've run covers without any baffle and didn't have any noticeable oil consumption. A HV pump will only make things worse since they move more oil through the engine and the last thing you need is more oil waiting to drain out of the heads.

 

Can't get worse, I already have the HV oil pump... :D