Corvair Forum

This guy welded a nickel in under the accessory cover on his engine. IIRC there is a spring loaded fiber plate there on my '67 motor. Oil gallery?

He mentions the nickel at 0:10 like we know to look for it. Is that some recommended mod? https://youtu.be/Tjk_B74bzQ8?t=10

Why bypass the oil cooler bypass valve. Ok I get a plugged oil cooler and I do not want oil to go to the engine, but, just build pressure until a seal blows? There could be some reason to do this if using an external oil cooler maybe?

Hard to say what he was thinking. Maybe he just did not want to fix a broken oil cooler by-pass valve. The purpose of the valve is to ensure any restriction in the oil cooler will cause the by-pass open at a set pressure to ENSURE oil by-passes the cooler and goes directly to the engine oil galleries.

A weak or bad by-pass valve results in some or all oil by-passing the cooler to the engine galleries. A blocked by-pass with a restricted oil cooler causes a lack of oil to the engine galleries and ruined bearings. GM didn't spend money on that by-pass valve for no good reason.

Note there is also an oil filter by-pass valve.

The half as**d stuff I find in amateur engine rebuilds always amazes me.

I saw this on a guys page when installing an external oil cooler in the front of the car. He also modified the housing for external oil lines and removed the filter block as he mounted the oil filter remotely in the front of the car. He had some pretty big lines running to the front of the car, something like a 1/2 inch. Was also using a high flow high pressure oil pump. I think the reasoning was he needed to make sure as much oil as possible was flowing through the front oil cooler as possible to keep a highly modified engine cool.

Over the years I've seen some "imaginative" modifications that don't stand up to rigorous engineering evaluation.

66vairguy wrote: ↑Tue Nov 10, 2020 9:30 am Over the years I've seen some "imaginative" modifications that don't stand up to rigorous engineering evaluation.

I bought my '67 Monza in 1980. The previous owner of my car did a lot of "upgrades" to the car and 140 motor, based on his bible, Finch's "How to Keep Your Corvair Alive". Some were OK, Finch was an engineer and racer and pioneer. Pushrod tube painting & shields were more PITA than necessary for a street car with modern Viton O-rings. He "bored out" the secondary carbs but it was a very rough finish, maybe he just grabbed a giant drill bit and went for it. One of the worst things was that he "streamlined" the venturi clusters by hand. He went too far and holed through in several places, so he just patched them up with epoxy...

He put a Dupree electric fuel pump in but mounted near the motor. It buzzed whenever it got hot (hot day, stopped at a light) because the fuel was vaporizing in the pump.

He milled the 140 heads too far, CR was too high, I had to run spacers under the jugs for many years until I had the heads heliarced back up. We milled them out properly and CC'ed the CCs in Mattel's model shop using a Volstro rotary milling head.

Just some of the upgrades I've undone.

He patched holes in the gas tank with pop rivets and fiberglass. It worked (no leaks) but it always seemed halfass. Turns out fiberglass is legit, today there are several commercial tank repair kits which use fiberglass.

Racers do that when they run a remote cooler. I feel it is not needed and certainly not when you run a stock oil cooler. Hi-flow pumps are rarely justified either.

Over the years painting the pushrod tubes to block heat has come under a lot of discussion.

First argument is you want to block heat from the exhaust tubes into the pushrod tube that will heat up the oil returning from the heads to the block.

Second argument is the pushrod tubes need to radiate heat FROM the oil that flows from the heads back to the block.

Both valid points - what to do? Now SOME use a heat blocking paint (or material) ONLY at the area on the pushrod tube next to the exhaust tube. The rest of the pushrod tube is painted with a paint that will radiate heat to help cool the oil as it returns through the pushrod tube.

Without evaluating oil temperatures it difficult to say how effective this is. However if you are racing a Corvair even a little improvement that will lower oil temperature is worth the effort.

Installing the stock oil cooler end covers (used on factory A/C cars) also helps improve oil cooling.

66vairguy wrote: ↑Wed Nov 11, 2020 9:55 am Over the years painting the pushrod tubes to block heat has come under a lot of discussion.

First argument is you want to block heat from the exhaust tubes into the pushrod tube that will heat up the oil returning from the heads to the block.

Second argument is the pushrod tubes need to radiate heat FROM the oil that flows from the heads back to the block.

Both valid points - what to do? Now SOME use a heat blocking paint (or material) ONLY at the area on the pushrod tube next to the exhaust tube. The rest of the pushrod tube is painted with a paint that will radiate heat to help cool the oil as it returns through the pushrod tube.

Without evaluating oil temperatures it difficult to say how effective this is. However if you are racing a Corvair even a little improvement that will lower oil temperature is worth the effort.

Installing the stock oil cooler end covers (used on factory A/C cars) also helps improve oil cooling.

To block the absorption of heat you have to look at emmosivity. You would probably want the outside of the tube to be shiny if not chrome as this blocks the absorption of heat, while the inside you would want to be a flat black as flat black absorbs the most heat.

I actually laugh at people with chrome headers that they some how think the chrome on the outside of the header helps. Its the inside of the header that would need to be chrome to help the most with keeping the heat in the header and direction it further down the exhaust.

On my Spyder I'm looking at getting the inside of the exhaust manifolds Jet coated along with all the piping going to the turbo. I know a lot of people wrap them, but I hate the look of wrap and I hate how it seems to accelerate the rusting away of pipes.

Just for fun I tried a nickel in that hole today, expecting a satisfying, glove-like fit.

Too big, doesn't even fit. Boo!