Too much pressure?, Still leaks some Options

[Wew]

Hi all
Engine is a 1973 2.0 with a 2056 build. I purchased a cam that was more aggressive for spirited driving no track and just large enough to maintain the car running fuel injection DJet. New heads with no vents.

purchased the oil tower and air box for a 1975/76 as the bigger breather opening was recommended.

I am still experiencing some oil leaks one that sits at the base of the head near the number 4 spark plug. Plug is not leaking. Also some oil on the thermostat spring mechanism.
Valve covers have had inner lip welded and 914 rubber cork gaskets.
I bought this canister to help with the pressure and hopefully remedy the oil leaks.



I have been unable to find an example of how to route the hoses for this when installed.

Any advice or pointing me in the right direction would be appreciated.

[mate914]

Hi all
Engine is a 1973 2.0 with a 2056 build. I purchased a cam that was more aggressive for spirited driving no track and just large enough to maintain the car running fuel injection DJet. New heads with no vents.

purchased the oil tower and air box for a 1975/76 as the bigger breather opening was recommended.

I am still experiencing some oil leaks one that sits at the base of the head near the number 4 spark plug. Plug is not leaking. Also some oil on the thermostat spring mechanism.
Valve covers have had inner lip welded and 914 rubber cork gaskets.
I bought this canister to help with the pressure and hopefully remedy the oil leaks.



I have been unable to find an example of how to route the hoses for this when installed.

Any advice or pointing me in the right direction would be appreciated.

The air vent next to oil fill.
Matt (IMG:style_emoticons/default/flag.gif)

[Wew]

Just splice the line of the big breather hose between the tower and the air cleaner?
Sheesh, I have been over thinking this.
Thanks for the info, much appreciated.

Hi all
Engine is a 1973 2.0 with a 2056 build. I purchased a cam that was more aggressive for spirited driving no track and just large enough to maintain the car running fuel injection DJet. New heads with no vents.

purchased the oil tower and air box for a 1975/76 as the bigger breather opening was recommended.

I am still experiencing some oil leaks one that sits at the base of the head near the number 4 spark plug. Plug is not leaking. Also some oil on the thermostat spring mechanism.
Valve covers have had inner lip welded and 914 rubber cork gaskets.
I bought this canister to help with the pressure and hopefully remedy the oil leaks.



I have been unable to find an example of how to route the hoses for this when installed.

Any advice or pointing me in the right direction would be appreciated.

The air vent next to oil fill.
Matt (IMG:style_emoticons/default/flag.gif)

[r_towle]

no vents on the heads may be a bit optimistic.
Lots of pressure up there that needs to go somewhere.

Its either out, or past the valve guides

[technicalninja]

Not enough info for me yet on this one to help.

Have you checked crankcase pressure?

Have you checked compression and LEAK DOWN!

How many miles on new engine?

Sounds like the root problem is oil leaks...

Quick test: Seal all engine vents, run engine at idle for a couple of minutes.

Remove oil cap.

Was it pressurized?

Can you feel pressure or pulses when you cover it with your hand?

Have someone raise the RPM to 3000.

Retest in the same manner.

You can also use a low-pressure vac/fuel pressure gauge in the vent with the engine sealed and running.

You're checking "blow by" here.

Most of the time, when you're having a problem, you will feel air blowing out of the fill tube or STRONG pulses when covering it with your hand. The longer you seal it the higher the pressure climbs.

Oil leaks can be caused by too much crankcase pressure.
They're more likely to be caused by other things...
Sounds like you have leaks on both sides.
I like the UV dye kits from TracerLine. Their LED based lights are awesome!

The pully bolt for the thermostat wire extends completely though the case and can be a source of leaks. Needs to be sealed at install IMO.

The rt side might be oil cooler/oil pressure sending unit.

What compression?
What cam?
What piston/barrels?
Exhaust?

[technicalninja]

no vents on the heads may be a bit optimistic.
Lots of pressure up there that needs to go somewhere.

Its either out, or past the valve guides

They share atmosphere through the pushrod tubes. Actual pressure in the valve cover should be exactly the same as at the fill tube.

Now, he's RIGHT!!!!

You should have circulation throughout the engine!
Actively reducing crankcase pressure ALWAYS help any engine...
High end drag race set ups will often have a dedicated vacuum pump (that dumps to the atmosphere-not for emissions at all!).
This pump reduces crankcase pressure to assist in the sealing of the rings.
They pull pretty HARD!

I'm planning on running the head ports as inlets and the crankcase port as suction.
I want fresh air in at heads and out at fill tube/dedicated crankcase port high on the motor.
The output I'd run to a catch can as you have now.
I'm planning on venting the catch can (vapor side only) to manifold vacuum through either a fixed orifice or maybe a PCV valve.
This set up only works properly with a plenum-based intake.
ITB guys have more trouble with this.
I'd normally just vent to atmosphere through catch can with ITBs.

Venting the catch can to atmosphere is the easy button...

[Jack Standz]

Might find this useful (from Len Hoffman and Jake Raby):

https://newsite.hamheads.com/2016/12/10/typ...tests-analysis/

And this:

http://www.914world.com/bbs2/lofiversion/i...hp?t296921.html

We don't vent the heads on ours. We run an AN -12 (?) From the oil filler tower to a catch can & that's it.

[technicalninja]

Bingo! That's a great article!

Only one GLARING difference on that engine though...

He's dry-sumped!

He's got a built-in vacuum pump!

Dry sumping any engine changes the "hurricane inside".

Now the bit about venting the heads was worth its weight in gold...

Just created another question for me.

Anyone created a dedicated drain back from the heads to the crankcase?

Pumping all the oil in the engine up into the head IS a problem for early American V8 stuff. I always hog the shit out of the drain back ports on those. This is even more critical with high rpm and high flow oil pumps.

Another thing, just remembered...
Every single dry sump equipped engine I've seen has a vacuum relief valve (sometimes adjustable!) somewhere in the engine case. Normally valve cover based in most examples.
I thought that was SOP for a dry sump.

[Jack Standz]

Some increase the size I f the drains on the windage tray (or remove some louvers) and/or grind the case in the attempt to improve draining back to the sump.

Maybe the later type iv motors didn't have a windage tray? (Can't remember for sure). In other words, removing it may help drain back more than any negative effects to windage?

[technicalninja]

One thing I noticed in a Raby video where he demonstrates the difference between cases was ALL of his prepared cases had an extra hole, looked 3/4 diameter. in the oil tower wall, up high, looked like it would be just under the tin in line with the fan housing.

Only thing I could come up with was crankcase ventilation...

I'd LOVE to know what they are for...

Every case had it. It's not stock. He didn't say anything about them.

[Jack Standz]

Wow, good catch. I've seen that video before and just rewatched it. Somehow missed it the last time.

It's hard to tell, but the one he says he's putting in a 356 doesn't seem to have the hole (middle case of the 3). I agree that it's probably some kind of crankcase ventilation. It's pretty much at the highest point on the case, which is where you want to vent the case. It's where we have ours (on the plastic housing that has the oil fill cap on top. Some run a fitting or hose to/through the oil fill cap, but that seems like a pain to remove every time you need to add oil.

One other possibility is that it could be a way to add oil to the motor if you're running either an upright system or a flat fan system. But, since he's said that the head vents (if available on your motor or valve covers) should be plugged, I'm voting for it being crankcase ventilation. Because where else would you p ut a vent??

BTW our next motor is a 2615, have all the parts. Just need the time to work on it. Of the 1.7, 1.8 and 2.0 liter cases in the hoard, we have 3 core 1.7 liter cases and two of them are "W" cases. The plan is for the 2615 project to use a "W" case because it's the strongest of them.