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Posted

Hey guys,

 

Just wondering what kind of pressures to expect in the crank case.

Reason being is that I'm blowing the sump gasket repeatedly. I've tried using only the gasket

and I have also tried with gasket silicon + gasket. Both seem to sprout leaks.

 

It is not a major leak but enough to make a plate sized puddle in 10 mins at idle.

 

Basically as many of you may know I've gone EFI, but I was too lazy to make a blanking plate for the original fuel pump.

The fuel pump has been leaking about a drop of oil every 5 mins so it didn't really bother me too much at all.

I had a bit of free time recently so I made up a blanking plate and removed the pump just last night.

 

So this morning I warmed up the car ready for work and all looked good, not a drop of oil coming from the blanking plate.

I then give the engine a bit of a rev and splat, oil starts dripping down at the rate of a plate every 10 mins.

So now that the fuel pump is no longer releaving pressure it has gone through the weakest point at the sump gasket.

 

Now I am thinking that because I have used silicon along with a gasket it could of just had a bad seal that was holding on

good enough because it did not have too much pressure on it. So when the plate was put on all the pressure went on it and pop, off it went.

What I am planing to do is use something allot more sticky that will guarantee a seal but..... Did the seal pop because of too much pressure

in the crank case or just because it was a bad seal?

 

My car currently has only one line coming from the rocker cover which goes directly into the plenum so it is under vacuum the whole time.

Should I drill a hole into the blanking plate, put a fitting on it and run it into the intake? Or should I just seal up the sump and hope I don't blow a rear main?

 

Cheers!

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Posted (edited)

edit:

 

just re read. that crank case vent on the k motor usually goes to atmosphere pressure (or close to it) certainly not under heavy vacuum, maybe a little bit of vaccuum.

 

where exactly is it placed? between the throttle and the valves? if so how are you getting massive possitive pressure in the crank?

 

the little valve on the rocker cover stuck closed?

 

 

as for pressures...if the crank case is sealed up completely, i suspect the pressure could get very high......

 

funny story, we turboed a 12a rotary, and about 2yrs on, only just realised we have been pressurising the crank case with 19psi of pressure. sort of maybe forgot to put in a 1 way valve. happy to report no dramatic effects present, interestingly no leaks of any kind, not even from the sump gasket.

Edited by ke70dave
Posted

There is one connection on the top my rocker cover (4kEFI cover)

and that goes back to the intake, I think I might make another line from the blanking plate for good measure.

Posted

what about taking that current vent, and just venting it into the intake track somewhere (pre butterfly)

 

and blocking off the port in the intake manifold.

 

though i can't see why the current setup wouldnt get rid of any excess pressure?

 

surely if its connected from the rocker cover to the intake manifold, the vacuum in the intake manifold would suck all the excess air out of the crank case?

 

unless.....there is just too much air to suck? how are the rings/valve stem seals in the engine?

 

how much air comes out when you open the oil cap with engine running? thats a good test.

  • Upvote 1
Posted

Just a pointer, don't use silicon, use a non hardening gasket like Permatex number 5. Aand your sump bolts should be only slightly tighter than hand tight, it's very easy to pinch these gaskets.

Posted

This sounds a bit weird to me, does it still do it if the dipstick is pulled out, this would check whether it is actually positive pressurization? You might even be able to feel pressure from the dipstick tube. I'm with Philbey, you could well be ruining your sump gaskets, it doesn't take much.

Posted

Cheers for the feedback guys.

I would say that I've definitely over tightened them as I've gone far beyond hand torque.

So what I will do is get the new gasket on, hand tighten + quarter turn. For good measure I'll also add a barb fitting to

the blanking plate that will go back to the intake.

Posted

Three bond is the stuff to use,Japanese made and used by Toyota, also did you check your sump to see if it was straight before putting it on, they squish around the bolt holes and don't pull the sump down properly.

Posted

threebond is the BOMB! after 5 sump gaskets on 2 k motors i also found removing all the studs and using bolts and washers also help

 

just don't over tighten them!

Posted

Why hasn't anyone mentioned to remove the gasket and use silicone instead?

 

Are you sure it is coming from the sump and not comeing from the oil filter head and making it's way around the sump?

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