The V8 Owners Forum -

The engine was rebuild a few years ago and was waiting for 5 years to be installed. In 2016 it was mounted and got a few test runs, all in all 50 miles. It runs fine, 3.5 with quad Dellortos, just back from the rolling road this week. What really disturbs me are the leaks. One leak is the back side of the oil pan. That will be solved when changing the oil again this month. The real problem is the leak at the dizzy stump. I changed from a dizzy bolt for the clamp to a stud, still leaking. I changed the O-ring, still leaking. I put an additional small gasket on top of the stump, still leaking. I disconnected the additional oil feed pipe from the oil pump for the dizzy, still leaking. I used an existing thread in the timing cover on top to mount a NPT adapter with a tube to give the "pressure" a way our, still leaking. I have dry valley clamps and seals front and rear, no leaking. I have 4 breathers on the rockers. So enough "breathing" I guess. Why is oil still coming out of the dizzy stump?
I have added some pics. The red fluffs are from a red rag I put in when driving a few miles to avoid oil over the front.

may I have a wrong dip stick and too much oil in? I don't want to risk an engine damage running too less oil. I have an oil pan with with one side wing and an additional oil cooler.








Thanks in advance for some replys.

It does sound like you have excess crankcase pressure. Have you tried removing the oil cap with the engine running? It should 'suck' slightly there rather than 'blow'.

What about the joint between the timing cover and the block at the very top. The last picture shows stains running down from that area.

DaveEFI wrote:It does sound like you have excess crankcase pressure. Have you tried removing the oil cap with the engine running? It should 'suck' slightly there rather than 'blow'.

How is there going to be a vacuum created in the crankcase?

Darkspeed wrote:

DaveEFI wrote:It does sound like you have excess crankcase pressure. Have you tried removing the oil cap with the engine running? It should 'suck' slightly there rather than 'blow'.

How is there going to be a vacuum created in the crankcase?

It is (should be) connected to the inlet manifold, so runs at negative pressure. If for any reason it runs at positive pressure, it is far more likely to leak.

DaveEFI wrote:

Darkspeed wrote:

DaveEFI wrote:It does sound like you have excess crankcase pressure. Have you tried removing the oil cap with the engine running? It should 'suck' slightly there rather than 'blow'.

How is there going to be a vacuum created in the crankcase?

It is (should be) connected to the inlet manifold, so runs at negative pressure. If for any reason it runs at positive pressure, it is far more likely to leak.

But he has quite clearly told us he's on quad Del's and they do not have manifold connects for crank PCV so will always run a slight positive which is why he has 4 breathers.

Sorry - not familiar with the plumbing on those. But the same principle applies. If pressure can build up inside the crankcase, it is more likely to leak oil.

DaveEFI wrote:Sorry - not familiar with the plumbing on those. But the same principle applies. If pressure can build up inside the crankcase, it is more likely to leak oil.

Agreed - sounds like it's always going to be prone to leaking.....

Chris.

DaveEFI wrote: If pressure can build up inside the crankcase, it is more likely to leak oil.

That's the problem, IMO.
Isn't it possible to route the breathers to a catch tank and then the exit of the catch tank vents via a venturi into the exhaust? That should give a negative pressure in the crankcase.

Thanks guys.

I have really thought of mounting this:

http://www.ebay.de/itm/401297688839?_tr ... EBIDX%3AIT

Will give it a new try with little oversized O-ring. But there will be still some pressure that will out I think

I ran a Chevy a few ago just with two breathers on the rockers. No PCV, no problems at all.

BTW the valle clamps and seals are really dry. It seems that there is a small line of oil but that is just from cleaning the mess.

Unless you have a chrome fetish, I'd say the standard set-up is more than capable of venting the block as long as it is connected to a source of negative pressure, in my opinion.

All you are going to do is pay for a bunch of kit that still needs to be plumbed in like the existing parts, so I would start by seeing if the current stuff will work and then get the shiny stuff if you want to later.

Would using a vacuum pump for diesel van brakes work and be easier to plumb in?

Ian

Other thing might be given the engine was rebuilt and only done a few miles is the rings may not have bedded in fully yet.

Try a bit of PTFE tape around the bolt threads.