Oil Leaks

hambone · Post by **hambone** » Sun Jul 19, 2009 7:30 am

Type1, 2500 miles thereabouts

The leaks started out innocently enough, a few drops from the front engine bottom after a run, also from the oil pump. During our recent trip I've now noticed a splattering of micro-drops on the driver side firewall. I can't find the source though...the engine tin seems dry. Leaking main seal or gallery plug are the likely suspects, but how is it getting on the firewall and such tiny droplets? Even a few up on the ceiling. Flywheel flinging it about at 65 MPH? I dunno.

The engine is running wonderfully otherwise. I see an engine drop in the future...I'm surprised at the leaks really, was very careful during assembly. Any thoughts or advice?

I started getting nervous, then realized you guys are out there! Thank God for the pseudo-Amish.

Bookwus · Post by **Bookwus** » Sun Jul 19, 2009 8:03 am

Hiya Bob,

hambone wrote:........Leaking main seal or gallery plug are the likely suspects, but how is it getting on the firewall and such tiny droplets? Even a few up on the ceiling. Flywheel flinging it about at 65 MPH? I dunno......

I'm thinking that such a leak, unless it were a real gusher, would simply trickle out behind the flywheel and leak out the weep holes at the bottom of the bellhousing. Is your bottom wet?

Any thoughts or advice?

Just a thought...........you mentioned that you had "micro-drops". To me that conveys the idea of a fine mist of oil. That, in turn would mean that the source of your leak would have to be exposed to a high volume of air movement. Possibly the oil cooler ?

I started getting nervous, then realized you guys are out there! Thank God for the pseudo-Amish.

Let's build a barn!

hambone · Post by **hambone** » Sun Jul 19, 2009 2:28 pm

It's been leaking from the bottom front like you'd expect.
The drops are more of a splatter than mist, and only a few form after a hard run, 20 or so, then drip down the firewall. There is a slight gap in the head tin where oil COULD come from, but it's not wet.
I guess the only way to know for sure is to pull the engine.

hambone · Post by **hambone** » Mon Jul 20, 2009 8:22 am

Well, we took a look last night. Most of the oil is coming from the main seal or cam plug, but nothing really excessive. Needs changing though.

Also, a pretty good amount is coming from behind the crank pulley. Remember those 1/4" of shims to align the pulleys? Apparently the oil slinger threads on the pulley are too far out from the case, causing oil to seep out and occasionally get flung around the engine compartment. It's not terrible, but I can imagine it making quite a mess in a few years. There is some oil pooled in the drip-tin below the crank pulley as well.

Also, there appears to be some blowby of sorts from the piston/head mating area. 1&2 have been stained by something dripping out. When started cold, the engine has always been very growly for about a minute until it warms up a little then goes away. The heads must have a compression leak when cold. Gypsie also noticed some noise coming from 3&4 head area when cold. I hope t he heads aren't damaged, but it has done this since the engine was installed and it seems to have plenty of power once warm.

I'm feeling a little bummed that my pretty new engine already has scabs and sores. Runs well otherwise...
I think it's time to pull the engine and retorque everything. Hopefully this can wait a few weeks?

The joys of antique aircraft. Bummer.

Bookwus · Post by **Bookwus** » Mon Jul 20, 2009 8:26 am

Hiya Bob,

hambone wrote: .....Most of the oil is coming from the main seal or cam plug, but nothing really excessive....

How the heck is it getting itself splattered on the firewall?

spiffy · Post by **spiffy** » Mon Jul 20, 2009 8:44 am

I have some leaks too, I figure it is just good measure to pull a fresh engine after the first few thousand miles to check everything.

I'll be pulling mine in august to install the new trans anyway.

fancy pants · Post by **fancy pants** » Mon Jul 20, 2009 9:48 am

Hambone, I am happy to help out when the time comes to pull it.

Just let me know...

hambone · Post by **hambone** » Mon Jul 20, 2009 10:53 am

Thanks John I will take you up on that.

Hey Spiff where is yours leaking? How is that dual lip main seal working? Recommended?

Mr. Bookwus, my theory is the crank pulley is flinging a random drop into the 65mph generated wind vacuum in the engine compartment, onto the firewall. That's the only thing I can figure right now.

spiffy · Post by **spiffy** » Mon Jul 20, 2009 11:48 am

hey Bob, it's leaking a drip drop by the oil pump cover. Tough place to get sealed perfectly.

The double lip seal seems to be doing very well. No leaks on that end of the engine.

hambone · Post by **hambone** » Mon Jul 20, 2009 12:13 pm

Where'd you get the seal?
Can't tell if mine is leaking at the pump cover or only from the pulley...

spiffy · Post by **spiffy** » Mon Jul 20, 2009 1:11 pm

hambone wrote:Where'd you get the seal?
Can't tell if mine is leaking at the pump cover or only from the pulley...

I think I got it from aircooled.net.

hambone · Post by **hambone** » Mon Jul 20, 2009 1:38 pm

Cripes!
Heck I never knew such a thing existed.

hambone · Post by **hambone** » Tue Oct 20, 2009 10:37 am

I have amassed all the parts, and some resolve and hope to drop the engine after this upcoming camp trip. The oil leak seems to be increasing and the engine bottom is moist with oil.
That 2-lip seal is actually 2 narrow seals. It will be a treat to try to get them to seat.
I will be needing some advice once I get to that point, I sure don't want to go thru this again...

sped372 · Post by **sped372** » Tue Oct 20, 2009 2:33 pm

I'm very interested in this... have to do the same thing in a couple weeks here. Hope all goes well.

hambone · Post by **hambone** » Tue Oct 20, 2009 3:14 pm

I'm hoping the source of the leaks is fairly obvious. It sure sucks to see a nice new engine all oily. VW Germany musta had it down.

Itinerant Air-Cooled

Itinerant Air-Cooled

Oil Leaks

Oil Leaks

Re: Oil Leaks