I just rebuilt an engine for my Bronco and I am having a strange problem. It is a 289 with 70 351W heads, roller cam, roller rockers.

The heads were rebuilt, a Machine Shop bored honed and assembled the short block. My friend who is a mechanic and I installed the head rockers, oil pump and oil pan.

We tried 3 oil pans, 3 oil pumps, and three pickups to get a good combination. I have an early bronco that needs a rear sump pan with a dipstick tub provision in the pan. The pan I used is an econoline pan from the early 80s.

What happens is when I am driving on local routes at speed and changing direction, elevation, or both, I get a giant smoke screen. The way to describe it is like dumping oil down the carb. It is that white blue and has the smell of oil, and I am loosing oil in the pan. Then it goes away, back to normal.

Otherwise no problems.

My friend who helped my put the engine together is pretty sure it is windage from what he has seen and experience.

Just wanted to see if anybody can give me an idea before I pull the pan and install the pan off the old 289 I pulled out.

 

Windage is the power loss caused by the friction of the oil in the engine coming into contact with the moving parts inside the engine in a non-lubricating capacity. This is generally oil splashing against the counterweights of the crank as it spins, and doesn't involve oil being drawn into the combustion chambers and burned. For this to happen, you'd have to have pretty bad rings. But what may be going on is that with all the different combos of pans, pumps and pickups you've used, you may have wound up with a dipstick that's incorrect for your engine and have too much oil in the sump. How many quarts are you putting in to fill it? Also, are you running a PCV valve, is it new and is it plumbed correctly? That's the most likely connection between the crankcase (valve covers, actually, but there's oil in there too) and the intake.

Perhaps the oil drainback holes in the heads aren't allowing the oil to return to the crankcase quickly enough and when you change direction as you indicated above, the oil in the valve covers sloshes into the PCV valve and is sucked into the intake.

 

In response to you message. My mechanic friend and I did a compression test before we fired over the engine and the guage indicated normal, that is per him, because he does have more experience than I do. I also personally know the machine shop that did the work, and they have a good reputation in the area and do a lot of work for performance shops. Took a drive with one od the guys at the shop and we couldn't get it to smoke on that drive. I don't think I have bad rings..... They are simple ahsing powerflex, which is what KB recommends with the pistons I have.

The engine that was in there before, the original 289 had bad rings. The engine has been in there three months, and usually with blow by you oil pan and intake gaskets start leaking hard and fast in less than that time. The engine smokes all the time... And puffs on acceleration. I don't have the problems. Even the old engine with blow by, and it was bad... didn't smoke like this. This is a go-go gadget smoke screen! Huge!


Interesting what you said about PCV valves. I am running the motorsports high rise valve covers. They have the baffles installed. The PCV valve is in great shape. Put I did notice that there was oil on the bottom of it when I checked it this weekend. So maybe what you are saying about the drain holes is correct, especially since I got windsor heads on a 302 block. But I don't know if that is a common problem with this combo. Somebody told me to stick the PCV in a breather to raise it up a little and that might help with the situation you are talking about. What are your thoughts?

Also heard that windage can be caused by oil sloshing up the pan and hitting the counterweights of the crank. Then the crank slings the oil all over the engine, especially up the cylinder walls on the right hand side since engines spin clockwise, usually..... The amount of oil is usually too much to wipe away for the oil ring on one stroke and therefore you get smoke.

I know it's usually a racing problem when you are hard cornering.... but the 289 does have bigger counterweights than a 302.... the main girdle I have laying around from my mustang days wouldn't work because the counterweights hit it in two or three places.... I figured that would be the most likely culprit, or at least my mechanic friend thinks so.

I always fill the pan with 5 quarts, which I got at the capacity for an 81-84 econoline pan.

Stock Bronco pan has a significantly deeper sump in the rear than the econoline's middle sump....

So... to check the oil drain holes what should I do? I just want to do all the simple stuff before I recondition the old pan, pull this one and see what that does!!