Turning a $19 Valve Cover Gasket Into a $5,000 Engine Rebuild

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You know how this goes. You pull a thread on your favorite sweater and ten minutes later, you’re freezing cold, standing in a pile of yarn. That sums up my last few days with my 1965 Chevrolet Corvair.

I bought this car cheap last summer. A friend I went to college with implored me to visit with her dad, who had owned this car since 1995.

The good news was that it had been stored inside a garage, and the body was in pretty decent shape for an inexpensive classic car in New England.

The bad news was that it sat idle for a long, long time, and some of the issues that caused it to be relegated to permanent garage storage had never been addressed.

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With the help of my friends Jay Holdash and Max Hall, we got the car across town and into my garage. Within about an hour, we had pumped the varnish out of the fuel tank,  poured in five gallons of fresh gas, installed a new battery, put some air in the dry-rotted tires and — amazingly — with a few pumps of the accelerator and a turn of the key, had it running.

Instantly, though, it became obvious that the car needed some serious attention. This is a 1965 Corvair Monza, and as such, it has four Rochester H one-barrel carburetors bolted to the intake manifolds. Two of them — the secondary carburetors that open when anything more than about half throttle is applied — had stuck floats that wouldn’t shut off the fuel supply when the float bowls were full, so gasoline was pouring out of them at an alarming rate.

Last summer, for the sake of just getting the car running and driving a bit, I focused on new tires, blocking off the secondary carbs and running on the two primaries, which would be fine because I was just trying to assess its pros and cons and not running it around like the sports car it eventually will be. I had a blast with it last summer.

But a few issues became readily apparent.

The biggest issue was how badly it leaked oil. Most Corvairs leak, but this one was pouring pretty badly. It was leaking oil from the valve covers, from the oil pan, and from the most notorious source, the pushrod tube seals. It required a thorough sealing if I was going to drive it without leaving a cloud of smoke all over town, which was particularly embarrassing when I parked the car anywhere.


A few weeks ago, I set out to seal up most of the leaks, and then attack all four carburetors, which needed a good cleaning and rebuild.

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That’s where “While-You’re-In-There-Itis” really took hold. I started off with the pushrod tube seals. Replacing these 24 seals — one on each end of the flat six-cylinder engine’s pushrod tubes — means taking off the valve covers, removing each tube retainer and pushrod, and pulling off the old, dried up seals. It’s not a hard job, but pretty time-consuming. Next, I replaced the valve covers, which were easy enough to remove and seal up.

The oil pan in the Corvair is pretty simple to remove, and it’s just a simple, flat pan seal, not a complicated, multi-part seal like one you’d find in a Chevrolet 350.

Dropping the pan, though, resulted in work that will more than likely consume weeks of my spare time. If I had left the leak alone, I probably would never have found the remnants of the broken piston ring I found, stuck in a pile of nasty looking sludge at the bottom of the pan.

Not good.

Not good at all.

I messaged my friend Rob Siegel — who writes the popular Hack Mechanic column for the BMW Car Club of America’s Roundel magazine and lives a half-hour away — responded “As my friend Lindsey Brown, foreman at The Little Foreign Car Garage said to me, ‘Never go inside an engine unless you’re prepared to deal with what you find.'”

You’re a day late and a dollar short with that advice, Siegel.

Now, that busted ring leads to a whole lot of diagnosis, pondering, questioning, and decision-making that I really wasn’t planning on executing with this car.

The diagnosis part was supposed to answer a few questions, and it did, but none of the answers were any easier. Rob drove over to my garage to try and figure out exactly what was going on inside the engine, before we made the decision to take it all apart.

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We did a compression test which — as the name implies — tests how much air the piston can compress inside the piston. The number itself isn’t exactly important. What you’re looking for is consistency in all six cylinders.

That is — unfortunately — not what we got.

As you can see from my chicken scratch handwriting on this greasy sheet of paper, I’ve got some pretty wide, but not necessarily alarming variation between five of the cylinders, and one tired old cylinder that couldn’t blow out a birthday candle.

The variation in compression in the other five might be something I could live with. Rings get stuck when they sit for a while can free up with use and oil additives. Valves can be lapped for a better sealing surface without having to get into a full rebuild.

But then there was that big, fat zero next to cylinder #2.

The last time I saw a circle that scary, I couldn’t turn on the TV for a month:

Sooo, maybe I scour craigslist, all the local Corvair Society of America (CORSA) chapter newsletters and hope to find an engine that I can swap for something new and hot instead of spending time on the old wheezer I already have.

Trouble with that plan is, unless that engine comes from somebody who knows its condition and overall health, it could be as much of a time bomb as the one that’s already in the car, and end up costing a lot more money than what I’d dump into just the purchase price.

I could find a machine shop to Magnaflux the block and crank and do a full valve job on the engine I have, but the rest of it would be on my plate. How’s that gonna work?

Paying a professional to rebuild an engine in 2018 is kind of like painting a car. You used to be able to get away with a pretty decent paint job for $1,500. Those days are long gone. A rebuild on an engine like this requires finding somebody good, who knows these engines in particular. Based on the estimates I’m looking at, you’re talking anywhere between $3,000 and $5,000.

And that, friends, is how you get from changing a $19 valve cover gasket to a $5,000 engine rebuild.

But I’m not going to do that. Nope, I’m going to go the route that high school kids from the 1940s through the 1980s went.

Corvair engines are like early VW engines: air-cooled, horizontally opposed motors that are elegant in their simplicity. Each of the six cylinder jugs is independent of each other, meaning that if one is bad, you can swap it out for another.

I’m pulling the heads off and I’m going to get a good look at that #2 cylinder to see whats going on in there. Best case is that I can hone it, replace the rings and Bob’s your uncle. Maybe I’ll have to replace the piston. Worst case is that I have to replace the barrel. I can get a piston, rings and jug from Clark’s Corvair Parts for around $650.

While the heads are off, I’ll lap the valves so that they seal more effectively, and throw in a set of new valve springs.

Is it the best way to go? Probably not. But on its best day, this Corvair isn’t worth $5,000. Dropping that kind of coin on a new engine just isn’t happening.

Maybe I should just take up golf.

Craig Fitzgerald

Craig Fitzgerald

Writer, editor, lousy guitar player, dad. Content Marketing and Publication Manager at BestRide.com.