Help! My engine is blowing oil all over itself!

Hello,

I have a type III engine on a sandrail, recently rebuilt. The type III is the engine with the fan mounted to the crank (as opposed to the type I, which has the fan attached to the alternator/generator).

The engine ran fine for two weekends after the rebuild, but has recently developed a serious oil leak.

I'm getting oil leakage into the fan housing, which is blowing oil out all over the engine, dripping out the bottom of the fan housing, etc. I'd say it's going through something like 1/2qt per hour. This is with the engine initially filled to 2.5qts. Oil pressure is approx 25psi at idle, 50psi at 2500+ rpms.

Can someone explain to me what is supposed to seal the rear (pulley-end) of the VW engine? Looking at the back of the engine, there is the oil slinger (inside the case, of course), and then the fan, and then the pulley. Are the spiral threads on the fan responsible for keeping the oil from getting out?

My VW book (keeping your VW alive) says the threads "must be clean, or they will throw oil". Can anyone explain to me how these threads work? Is the leakage at all sensitive to the amount of torque that the pulley nut is torqued?

I'm not sure how the oil is leaking into the housing. If I take the fan off and run the engine (for a very short while), then of course oil slops out at a pretty good rate (I'm assuming that is normal with the fan/pulley removed), but if I put the fan in, I can't see where the oil is coming from.

Thanks, Scott (owner of the sandrail from hell)

Reply to
nospam
Loading thread data ...

Sounds like you got an oil cooler seal leaking... OR you could have blocked off the case vent... The spiral thread is there to keep the oil in, and is also the crank case air intake..

J.

Reply to
BergRace

If there is a problem with the rings, the additional case pressure will drive oil out past the slinger (among other places). A leak-down test will tell.

Max

Reply to
Max Welton

Hi.It sounds like your engine doesn't have a "sand seal pulley".For a motor in a buggy ,probably a good idea.Broken rings are another possibility,but try the easy way first.Steve

Reply to
Ilambert

Hello Steve,

Yes, I don't have a sand-sealed pulley. The engine is a type-III (fan on the crank instead of a pulley). Is it possible to put a sand seal on the type-III? The only sand-seal pulley's I have seen are for type-I/II.

I ran a compression check today, and this is what I got. The starter is broke, so these numbers are with two guys pushing the rail in third gear, and are thus a bit approximate.

dry: 60/90/90/90 wet: 80/100/100/100

The engine was overhauled approximately 10hrs ago. This leads me to believe that something has gone wrong with #1, maybe a broken ring?

Assuming it is a broken ring, does anyone know why it happened? When I rebuilt it (with new P&C), everything seemed to go together just fine.

The engine is also "stiffer" to turn than I think it should be (not having access to another engine, it's hard to tell), so maybe whatever is wrong with #1 has also stiffened things up.

I'm going to pull the head and have a look at #1 tomorrow.

Scott

Reply to
nospam

I think a sand seal pulley can be used.Isn't a T3 motor based on a T1?Maybe the Tinware is too different.I really don't know.Any T3 experts ?Steve

Reply to
Ilambert

To add a sand seal to a type 3 engine you would have to modify the oil return grooves on the type 3 fan. I don't know if there is anyone who does this, but it should not be any harder than on a type 1 pulley, as long as you have a lathe which can handle the larger diameter fan.

To be fair, though, this is probably NOT the root cause of your problem. Even if the oil IS coming out there, you need to figure out why.

It's more likely that in the process of adapting the type 3 engine for your application you no longer have any crankcase ventilation. This is a common problem with people who try to convert 72-3 type 3 engines without understanding them.

Is this a late type 3 engine? Are there 2 plastic plugs on top of the breather box?

-

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

-----------------------------------------------

Reply to
Jim Adney

Hello Jim,

I have one of the oil filler tubes with a crankcase vent on it (it has a little hose fitting, maybe for something around 1/2? diameter hose), and I installed one of the little k&n filters on it.

Removing the filter did lessen the oil leakage, but did not eliminate it. Pulling the oil filler cap reveals a lot of blowby at high rpm. This is a newly rebuilt engine.

After taking the heads off, I did find the gaps on the oil rings on the number 1 piston/cylinder directly aligned; I don't know how they got that way -- I believe I had put them 120 degrees apart, as recommended by my book.

I examined the cylinders, and no grooves, scratches, dings, dents, or anything else weird in the cylinders.

Also, as a possibly related thing, I found four bent pushrods when I pulled the heads (3 exhaust, 1 intake). The engine is completely stock (cam, rockers, etc). The pushrods were of the high-performance chromoly type. Any ideas anyone? They were bent just enough for the pushrods to start scraping the sides of the tubes.

And yes, I did look at the top of the pistons -- they look brand new, no evidence of a valve contacting a piston.

Thanks, Scott

Reply to
nospam

Your breather box should have a metal tube that goes down to that pipe and connects to it with a short length of hose. The breather box should have a vent pipe on it. If you don't have a vent up there, then you may have a problem. I'm not sure what will happen if you try to vent from the filler pipe as you describe. That striks me as awfully close to the oil level, so that oil might well be blown out there. You certainly don't get any of the oil mist separation that the breather box should provide.

I know experienced mechanics who claim that the gaps migrate around. Proof of this is that we don't see ridges in the cylinder walls where the gaps have been. If they stayed at the same place they would leave wear ridges.

Either sticky valves or poor quality pushrods. With your engine I'd stick to OE pushrods anyway. They expand correctly as they warm up, so you know how to set the valve lash. Stock valve lash settings certainly can't be right with steel pushrods. If it was just sticky valves, it is probably okay by now, so you should be able to drop in some OE pushrods (which are lighter anyway) and be back in business.

Good!

-

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

-----------------------------------------------

Reply to
Jim Adney

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.