3.0 liter Corvair Buggy motor with possible ring issues

[Matt E.]

This is my first post here since the migration ( exodus) from the CCF. I purchased this 3.0 Liter monster at an estate buyout. The executor knew very little about this engine except he thought the deceased owner had it running only briefly. All indicators are that it's been run, but not much. It doesn't look like its ever been installed in a vehicle. The engine didn't have a carburetor, distributor, idler pulley or belt. I made the engine whole, spun up the oil pressure and it fired up. It idles with very little smoke, but when you bring the throttle up it smokes a LOT on the right (passenger bank). I Shut it down and did a compression check. One cylinder at 145-the rest at 160. I suspected oil ring at this point. I pulled the exhaust log on that side and started it up.Smoke and oil were spewing out of # 1 only so I suspect the problem lies there. My question is threefold: Is my diagnosis correct? Since the engine appears newish maybe it wasn't broken in correctly. Is there something I can try that won't hurt anything? If I need to replace the rings do I do just #1 or the whole right bank? I don't know what I'm going to do with this engine ultimately, but I'm having fun playing with it. And by the way...it sounds fantastic!

[cnicol]

I'd pull the head and #1 barrel and look at the rings and cylinder wall. Probably a cracked ring, possibly scored barrel. Tight or loose ring gaps?

Welcome to the friendly forum.

[joelsplace]

I might be tempted to run it a little longer. Possibly he was over zealous with the assembly lube?

[RexJohnson]

Maybe stick a bore scope down number 1 and see if there is any scoring from a possible broken ring. If there is, probably don't want to run it anymore. If none then it probably wouldn't hurt to run it.

[Spectre]

The lower compression is on #5, but the smoke at #1. Perhaps the engine isn’t broken in at all if it was never installed.

[Matt E.]

First, thanks for your replies,Craig, Rex, Joel and David. It is nice to feel right at home with familiar names from the CCF. Your help is much appreciated! I was able to inspect the piston tops and cylinder walls with a bore scope. The engine appears to be new. Cylinder #1, and # 3 have some oil pooled at the bottom. To the degree I could maneuver the bore scope I didn't see any defects in any cylinder wall, just crosshatching. Cylinder #3 even still has some builder's felt pen marks! All of this leads me to believe that possibly the engine was never broken in properly. What do you think? I've never broken in a new engine before and I don't want damage this one if possible. Can you explain the procedure or point me to your preferred method in Corvair literature? I have access to a library of Corvair Manuals/Literature. Thank you.

[Dennis66]

That's a lot of oil in there. It could be that the engine was put in storage and they added oil to the cylinders. I'd bring it up to near TDC to pool the oil and take an absorbent rag and a long skinny screwdriver and see if I could soak up a little excess oil. Then I'd run it a while. Dennis

[Spectre]

Looks like that engine was possibly never run. It might just need a proper break in.

[Brizo]

Oil was "spewing from #1 cylinder" ? You might run it a while longer at about 1K rpm and see if it decreases, stays the same or gets worse. And then based on what it does, consider removing the head and #1 cylinder first to see what you find . Normally,, a new engine shouldnt be smoking at all.

[joelsplace]

I would pretend like it hasn't been run and do a 30 minute cam break in run.

[kmart356]

...snipped...All of this leads me to believe that possibly the engine was never broken in properly. What do you think? I've never broken in a new engine before and I don't want damage this one if possible. Can you explain the procedure or point me to your preferred method in Corvair literature? I have access to a library of Corvair Manuals/Literature. Thank you.

Here is a good read - Breaking in a new engine from Corvair Autocross Page by Bryan Blackwell

[66vairguy]

I haven't seen this mentioned, may have missed it, but did you verify the engine oil level? An engine with too much oil in it will leak into cylinders, especially if the car sits on an angle. It seems you don't have a manual fuel pump that can fill up the crankcase and thin the oil. A carburetor with a stuck float, or incorrect bowl level, will thin the oil. Did you smell the oil for gasoline?

I used the chrome plated rings on one engine and it took a few thousand miles for those to seat! On the next engine I asked the guy that did my machining work about rings and he said "Over the years I tried a lot of different types and brands of piston rings per customers requests. Some rings were of such poor quality the were OUT OF ROUND in the cylinder. Others took several thousand miles to seat in. If the cylinder cross hatch is not correct, some rings will never seat. If you want my recommendation, then use a quality cast iron piston ring for daily driving. They seat fast and are more than adequate for up to 80,000 miles. How many miles will you put on the engine in ten years?"

I used the GRANT cast iron rings (no plating) that California Corvair sells. They sealed quickly. No oil use after a few hundred miles. Compression is good, crankcase blow-by is minimal. Grants has a good reputation.

The most problematic rings, according to posters over the years, are Deeves.

Of course any ring can be improperly gaped or damaged during piston installation.

[Matt E.]

I tried following the break in procedure outlined in this thread and it is still smoking when revved.It's been a little over a week since I ran it so oil seems to have pooled in the barrels during that time. I was waiting on a new phone based bore scope to get a better look inside.BTW, they are inexpensive and work great! The scope showed significant oil in cylinder #1 and cylinder # 5. Cylinder 5 seems to have collected a brown oil sludge on the piston top that none of the other cylinders seem to have.The oil level is full, but not overfull. My intention has always been to sell this engine, so unless anyone has another idea, I will sell it as is rather than tear into it.I live near Tacoma, WA. Read the entire thread for compression numbers and other suggestions given. PM if you have an interest.

[belaraphon]

No one has mentioned the head. You may be pulling a lot of oil past the valves. The intake valves should have an oil seal on them, the exhaust don't. If the seals are there and in good shape I would pull the valve springs off those two cylinders and check for valve stem clearance. Put a dial indicator on the valve stem and wiggle it back and forth to check the clearance. The valve stem or guide could be bad/worn.

[66vairguy]

No one has mentioned the head. You may be pulling a lot of oil past the valves. The intake valves should have an oil seal on them, the exhaust don't. If the seals are there and in good shape I would pull the valve springs off those two cylinders and check for valve stem clearance. Put a dial indicator on the valve stem and wiggle it back and forth to check the clearance. The valve stem or guide could be bad/worn.

Good comments. A crude test is to let the engine idle a minute (high manifold vacuum) and open the throttle. If the oil smoke is abundant at first, but then lessens, it would suggest looking at the intake valve seals and guides.

[joelsplace]

I can't see how anything but a high oil level would cause that much oil in a cylinder from sitting.