<VV> Overheating - Deflashing Heads

Mark Durham 62vair at gmail.com
Mon Jul 26 16:57:52 EDT 2010

Bill, I assume you are using a full synthetic oil, because a regular oil
will not sustain those temps for very long without coking up on you. A 10-40
or even a 15-40 or 45 would not be unreasonable in this high heat.

Also, you can gain some temp relief by leaving off the bottom tin until
cooler weather. Some say 20-30 degrees cooler. that takes a few minutes to
do, so if you plan on driving the car more, make sure it has the right oil
in it and take off the bottom tin right away.

The tin and all of its components need to be in place to provide efficient
cooling, there is a whole list of stuff to do to make sure your car and
engine is AC ready in Clarks books, if you didn't do some of those things,
its certainly worth a look.

Have you calibrated your temp guages for accuracy?

You might even find that is sufficient, and not have to deflash.

Deflashing the heads is easiest done from above. You will have to remove
whatever gets in the way to take the top tin off, then do a thorough
inspection with a light in between the fins. Take the bottom tin off so the
flashing falls out onto the floor, and make sure you blow out any that stick
in the lower baffles around the cyl bases.

The drill will work for some areas, but I also used a fine hacksaw blade in
a hand held holder and trimmed out some areas as well. The drill bit would
work as a stopping point. Drill at the end of a cleanup area and then clean
to that hole. I also used a fine thin small file and a thin round file to
finish off rough edges.

Its hard work but worth the effort.


Mark Durham

On Mon, Jul 26, 2010 at 1:18 PM, Bill H. <gojoe283 at yahoo.com> wrote:

>                                                       B"H
> Hi all...since I installed A/C in my Corvair it's been nothing but trials
> and
> tribulations!  Last week, maiden voyage past my 4 mile commute to/from
> work,
> temp outside was around 95 degrees and we got stuck on the FDR Drive in
> NYC,
> bumper to bumper for over an hour in the hot sun.  I had to go upstate to
> answer
> a traffic ticket.
> The oil temp gauge kept getting hotter and hotter, got past 260 degrees and
> onto
> 340, no place to pull over.
> I shut the A/C off before that point.  However, as we idled our way up the
> east
> side of Manhattan, the TEMP/PRESS light came on, and I gingered the car as
> best
> I could till we could pull over (there's no place to pull over until you
> cross
> the George Washington bridge and get onto the New Jersey side of the
> border).
> She was pinging loudly too, but as soon as we crossed the state line we
> stopped
> at a rest area and I let her cool off for a few minutes, and the sun went
> behind
> the clouds.
> The temp went down to around 260, we got back on the highway but now there
> was
> no traffic, so she stayed just under 260, I turned the A/C back on and
> there was
> no pinging, nor did the TEMP/PRESS light come back on either.
> Coming back, it was raining, hail, thunder/lightening, etc. but she ran
> ok.  In
> fact, the A/C was a godsend because at least the interior was cool and
> de-humidified.
> As soon as we got back into Brooklyn, hot weather and idle, idle, and idled
> our
> way home.  Temp went back up, TEMP/PRESS light back on, pinging, etc. even
> though the gauge indicated 250 degrees for the oil.
> It hit me that not de-flashing my cylinder heads was a B-I-G mistake, and I
> better do this before I take the car out again on a trip.  She still runs
> and I
> pray to the Al-mighty that I didn't damage her engine permanently.
> .
> So, does anyone have suggestions for the best (and least intrusive) way to
> deflash the heads?  I don't mind removing the top shrouds if it doesn't
> take all
> day to do, and if it makes de-flashing easier.  Can de-flashing be done
> from the
> top of the engine instead of getting under the car.
> I've heard that a long 1/8" drill bit is the best way to go.  If that's so,
> then
> I assume that this size bit will fit in between the fins?
> I'd appreciate any and all suggestions and thanks...Bill Hershkowitz 69
> Monza
> 110 PG
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